Cloning and Sequence Analysis on cDNA of Growth Hormone Releasing Hormone Receptor Gene from Wuzhishan Miniature Pig

[Objective] cDNA of growth hormone releasing hormone （GHRH） receptor gene from Wuzhishan miniature pig was cloned and its sequence was also analyzed. [Method] Using genomic DNA extracted from porcine ear tissues of Wuzhishan miniature pig as the template, three pairs of primers were designed by the reported cDNA sequence of porcine GHRH, and cDNA was also amplified by RT-PCR. After being recovered and purified, PCR products were ligated to pMD18-T and then transformed into Escherichia coli DH5a. The transformation products were analyzed by PCR and double enzyme digestion to screen positive clones, and the positive clones were sequenced after identification in LB liquid medium. [ Result] cDNA of Wuzhishan miniature pig GHRH receptor gene was obtained successfully, and its length was 1 577 bp coding 423 amino acids. BLAST analysis showed that there were only 23 nuoleotides in difference between this fragment and pomine GHRH receptor gene, and its homology was 98%. However, both GHRH receptor genes were constituted by 423 amino acids with the sequence homology of 96%. [ Conclusion] This study provides theoretical basis for further studies on the dwarf mechanism of Wuzhishan miniature pig.

Isolation of Growth Hormone-Releasing Hormone and Its Receptor Genes from Scatophagus argus and Their Expression Analyses

The teleost Scatophagus argus is a species whose females grows faster than males.Growth hormone(gh)mRNA abundance in females pituitary is higher than that in males;however the mechanism underlining such differential is still unknown.Growth hormone(GH)is tightly associated with GH-releasing hormone(Ghrh)in vertebrates.In this study,Ghrh gene(ghrh)and its receptor gene,ghrhr,were isolated from S.argus.Tissue expression analysis showed that ghrh and ghrhr were mainly expressed in hypothalamus while ghrhr was expressed in pituitary and gh was predominantly expressed in pituitary.Twenty cultured S.argus individuals were used to compare ghrh,ghrhr and gh mRNA abundances,120 g and 181 g average weight for male(n=11)and female(n=9),respectively.Real-time PCR indicated that the ghrh and ghrhr mRNA abundances in male hypothalamus were significantly higher than those in female hypothalamus while that of gh mRNA abundance was significantly higher in female pituitary than in male pituitary.The ghrh and ghrhr mRNA abundances were significantly up-regulated in female hypothalamus 3 h after injection of 0.1 mg kg^-1 body weight Ghrh while pituitary ghrhr and gh mRNA abundances were not affected.In female hypothalamus,ghrh and ghrhr m RNA abundances were not affected at 6 h post-injection of 4 mg kg^-1 body weight 17α-methyltes-tosterone(17α-MT)or 17β-Estradiol(E2).In female pituitary,ghrhr m RNA abundance was down-regulated by 17α-MT while that of gh m RNA abundance was up-regulated by E2.Our findings indicated that E2,rather than Ghrh,plays an important role in up-regulating the expression of gh in female S.argus,which should aid to understand the sexual dimorphism of teleost growth.

Gastric motor effects of ghrelin and growth hormone releasing peptide 6 in diabetic mice with gastroparesis

AIM:To investigate the potential therapeutic significance of ghrelin and growth hormone releasing peptide 6 (GHRP-6) in diabetic mice with gastric motility disorders. METHODS: A diabetic mouse model was established by intraperitoneal (ip) injection of alloxan. Diabetic mice were injected ip with ghrelin or GHRP-6 (20-200 μg/kg), and the effects on gastric emptying were measured after intragastric application of phenol red. The effect of atropine, NG-nitro-L-arginine methyl ester hydrochloride (L-NAME) or D-Lys3-GHRP-6 (a growth hormone secretagogue receptor (GHS-R) antagonist) on the gastroprokinetic effect of ghrelin or GHRP-6 (100 μg/kg) was also investigated. The effects of ghrelin or GHRP-6 (0.01-10 μmol/L) on spontaneous or carbachol-induced contractile amplitude were also investigated in vitro, in gastric fundic circular strips taken from diabetic mice. The presence of growth hormone secretagogue receptor 1a transcripts in the fundic strips of diabetic mice was detected by reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: We established a diabetic mouse model with delayed gastric emptying. Ghrelin and GHRP-6 accelerated gastric emptying in diabetic mice with gastroparesis. In the presence of atropine or L-NAME, which delayed gastric emptying, ghrelin and GHRP-6 (100 μg/kg) failed to accelerate gastric emptying. D-Lys3-GHRP-6 also delayed gastric emptying induced by the GHS-R agonist. Ghrelin and GHRP-6 increased the carbachol-induced contractile amplitude in gastric fundicstrips taken from diabetic mice. RT-PCR confirmed the presence of GHS-R mRNA in the strip preparations. CONCLUSION: Ghrelin and GHRP-6 increase gastric emptying in diabetic mice with gastroparesis, perhaps by activating peripheral cholinergic pathways in the enteric nervous system.

Associations of Gonadotropin-Releasing Hormone Receptor (GnRHR) and Neuropeptide Y(NPY) Genes’Polymorphisms with Egg-Laying Traits in Wenchang Chicken

Single nucleotide polymorphisms （SNP） of chicken gonadotropin-releasing hormone receptor （GnRHR） and neuropeptide Y （NPY） were selected to identify the genotypes of Wenchang （Chinese indigenous breed） chicken with restricton fragment length polymorphisms. The associations of the SNPs with the total egg production （NE）, average days of continual laying （ADCL）, and number of double-yolked eggs （DYE） traits were analyzed. The frequency of restriction enzyme A/a alleles in the population was for GnRHR 0.69 （Bpu1102 Ⅰ A） and 0.31 （Bpu1102 Ⅰ a） and for NPY 0.46 （Dra Ⅰ B） and 0.54 （Dra Ⅰ b）. Trait data from a total of 120 hens, which were purebred introduced from Hainan Province, China from one generation were recorded. Two significant effects of genes＇ marker were found： for GnRHR and number of eggs （dominant; t= 2.67, df= 116） and NPY and number of eggs （additive; t= 1.97, df= 116）. The current research supports the effects of GnRHR and NPY genes on egg-laying traits of chickens.

Artificial Cycle with or without a Depot Gonadotropin-releasing Hormone Agonist for Frozen-thawed Embryo Transfer： An Assessment of Infertility Type that Is Most Suitable

The clinical outcomes of five groups of infertility patients receiving frozen- thawed, cleavage-stage embryo transfers with exogenous hormone protocols with or without a depot gonadotropin-releasing hormone （GnRH） agonist were assessed. A retrospective cohort analysis was performed on 1003 cycles undergoing frozen-thawed, cleavage-stage embryo transfers from January 1, 2012 to June 31, 2015 in the Reproductive Medicine Center of Wuhan General Hospital of Guangzhou Military Region. Based on the infertility etiologies of the patients, the 1003 cycles were divided into five groups： tubal infertility, polycystic ovary syndrome （PCOS）, endometriosis, male infertility, and unexplained infertility. The main outcome was the live birth rate. Two groups were set up based on the intervention： group A was given a GnRH agonist with exogenous estrogen and progesterone, and group B （control group） was given exogenous estrogen and progesterone only. The results showed that the baseline serum hormone levels and basic characteristics of the patients were not significantly different between groups A and B. The live birth rates in groups A and B were 41.67% and 29.29%, respectively （P〈0.05）. The live birth rates in patients with PCOS in groups A and B were 56.25% and 30.61%, respectively （P〈0.05）. The clinical pregnancy, implantation and on-going pregnancy rates showed the same trends as the live birth rates between groups A and B. The ectopic pregnancy rate was significantly lower in group A than in group B. We concluded that the live birth rate was higher and other clinical outcomes were more satisfactory with GnRH agonist co- treatment than without GnRH agonist co-treatment for frozen-thawed embryo transfer. The GnRH agonist combined with exogenous estrogen and progesterone worked for all types of infertility tested, especially for women with PCOS.

Expression of hippocampal corticosteroid receptors,as well as corticotrophin-releasing hormone and vasopressin in the hypothalamic paraventricular nucleus,in fornix transected rats

BACKGROUND： The hippocampus regulates the hypothalamic-pituitary-adrenal axis through negative feedback. The hypothalamic paraventricular nucleus receives neuronal input from the hippocampus via the fomix, OBJECTIVE： To explore whether the negative feedback effect of the hippocampus on the hypothalamic-pituitary-adrenal axis is contributed to the inhibitory effect of mineralocorticoid receptor （MR） and glucocorticoid receptor （GR） in the hippocampus on the paraventricular nucleus via the fornix. DESIGN, TIME AND SETTING： Randomized, controlled, animal experiment. The study was performed at the Department of Histology and Embryology, China Medical University between September 2006 and September 2008. MATERIALS： Rabbit anti-rat anti-MR and rabbit anti-rat anti-GR antibodies were purchased from Santa Cruz Biotechnology, USA. Rabbit anti-rat anti-corticotrophin releasing hormone （CRH） and rabbit anti-rat anti-arginine vasopressin antibodies were purchased from Wuhan Boster. METHODS： A total of 90 male, Wistar rats were randomly divided into model and sham-surgery groups （n = 45）. Fornix transection was performed in the model group, while the sham-surgery group underwent surgery, but no fornix transection. MAIN OUTCOME MEASURES： Immunohistochemistry was used to examine MR and GR expression in the hippocampus, as well as CRH and anti-arginine vasopressin in the paraventricular nucleus. Western blot was used to measure alterations in MR, GR, and CRH protein expression following fomix transection. RESULTS： Compared with the sham-surgery group, there were no obvious changes in MR and GR expression in the hippocampus, or CRH and anti-arginine vasopressin expression in the paraventdcular nucleus within 4 days of fornix transection. However, after 7-10 days, significantly decreased MR and GR expression in the hippocampus, and increased CRH and anti-arginine vasopmssin expression in the paraventricular nucleus were observed （P 〈 0.05-0.01）. CONCLUSION： Negative feedback from the hippocampus on the hypothalamic-pituitary-adrenal axis might be mediated through the fornix, and the corticosterene actions mediated by hippocampal corticosteroid receptors indirectly modulated the hypothalamic-pituitary-adrenal axis.

Long-term effectiveness of luteinizing hormone-releasing hormone agonist or antiandrogen monotherapy in elderly men with localizect prostate cancer （T1-2） ： a retrospective study

Aim： To evaluate the long-term effectiveness, side effects and compliance rates of two types of drugs （luteinizing hormone-releasing hormone [LHRH] agonist and antiandrogen） that were used individually to treat patients with localized prostate cancer （T1-2） at our institution. Methods： Ninety-seven patients who were diagnosed in the period from April 1997 to January 2000 as having clinically localized prostate cancer （T1-2） received either LHRH agonist （leuprolide acetate 7.5 mg/month） monotherapy （group 1, n = 62） or antiandrogen monotherapy （group 2, n = 35; 18 received bicalutamide 50 mg q.d., 13 received nilutamide 150 mg t.i.d, and 4 received flutamide 250 mg t.i.d.）. The mean age in both groups was 76 years. Results： The mean follow-up time was （50.8 ±8.5） months in group 1 and （43.1 ± 2.2） months in group 2. Prostate-specific antigen （PSA） levels rose in only 1 of the 62 patients （1.6%） in group 1, and in 20 of the 35 patients （57.1%） in group 2. In group 2, 10 of the 20 patients （50 %） with increasing PSA levels were treated with LHRH salvage therapy, and eight （80%） responded. Hot flashes （54.8%） and lethargy （41.9%） were the most common side effects in group 1. In contrast, nipple-tenderness （40%） and light-dark adaptation （17.1%） were more often seen in group 2. Only 1 of the 62 patients （1.6%） in group 1 switched to another medication because of adverse side effects; whereas 8 of the 35 patients （22.9%） in group 2 did so. Conclusion： Unlike antiandrogen monotherapy, LHRH agonist monotherapy provided long-term durable control of localized prostate cancer （T1-2）. It can also be an effective treatment option for patients whose disease failed to respond to antiandrogen monotherapy. The limitations of our study are the lack of health outcomes analysis and a small sample size.

siRNA-targeted inhibition of growth hormone receptor in human colon cancer SW480 cells

AIM:To determine the effects of RNAi-mediated inhibition of the growth hormone receptor(GHR)gene on tumors and colon cancer cells in vivo.METHODS:Construction of a eukaryotic vector for human GHR expression,the pcDNA 6.2-GW/EmGFPsmall interfering RNAs(siRNAs)-GHR plasmid,was used to inhibit GHR expression.Thirty-six BALB/c nude mice were randomly divided into groups and treated with normal saline(NS),recombinant plasmid(G2),growth hormone(GH),5-fluorouracil(FU),G2+FU or G2+FU+GH.Each nude mouse was subcutaneously inoculated with 1×107human colon cancer SW480 cells;the nude mice were weighed before inoculation and on the 2nd,5th,8th,11th,14thand 17thday after inoculation.All nude mice were sacrificed after 17 d.Each subcutaneous tumor was removed and studied.Tumor volume was measured on the 5th,8th,11th,14thand 17thday after inoculation.The expression of GHR protein in the tumor tissue was detected by Western blotting analysis,and the differences in GHR mRNA expression in the tumor tissue were detected by real-time quantitative reverse transcription-polymerase chain reaction.RESULTS:Compared to the control group,the weights of the inoculated nude mice on the 17thday after inoculation were:G2:21.60±0.71 g,GH:21.64±0.45 g,FU:18.94±0.47 g,FU+G2:19.40±0.60 g,G2+FU+GH:21.04±0.78 g vs NS:20.68±0.66 g,P<0.05;the tumor volumes after the subcutaneous inoculation were:G2:9.71±3.82 mm3,FU:11.54±2.42mm3,FU+G2:11.42±1.11 mm3,G2+FU+GH:10.47±1.02 mm3vs NS:116.81±10.61 mm3,P<0.05.Compared to the GH group,the tumor volumes were significantly decreased in the experimental groups.The GHR protein expression(G2:0.39±0.02,FU:0.40±0.02,FU+G2:0.38±0.01,G2+FU+GH:0.39±0.01 vs NS:0.94±0.02,P<0.05)and the GHR mRNA expression(G2:14.12±0.10,FU:15.15±0.44,FU+G2:16.46±0.27,G2+FU+GH:15.37±0.57 vs NS:12.63±0.14,P<0.05)were significantly decreased and increased,respectively,in the experimental groups.CONCLUSION:Inhibition of GHR in human colon cancer SW480 cells resulted in anti-tumor effects in nude mice.

Effect of growth hormone-releasing peptide on cardiac cholinergic nerve fiber density distribution in a rat model of heart failure

BACKGROUND： Changes in the cardiac autonomic nerve are considered to be important factors in the mechanisms of heart failure. It is possible to reduce or slow down nerve degeneration and necrosis, provided that patients take effective neuroprotectants during the early stages of heart failure. Moreover, it is possible to relieve the pathological process and reduce the risk of death. OBJECTIVE： To study the effect of growth hormone releasing peptide （GHRP） on cardiac cholinergic nerve fiber density distribution in a rat model of heart failure, and verify whether GHRP can ameliorate denervation. DESIGN, TIME AND SETTING： A randomized controlled study was performed at the Key Laboratory of Anatomy, Harbin Medical University, between June and October 2009. MATERIALS： Fifty adult, healthy, female, Wistar rats, weighing （200± 20） g, were randomly divided into GHRP （n = 30）, model （n = 10）, and sham operation （n = 10） groups. GHRP-2 was made in Shanghai, China （batch No. z071212-03）. METHODS： Acute myocardial infarction was established by ligating the left anterior descending coronary artery in the GHRP and model groups. Five weeks later, myocardial function was detected using color ultrasound electrocardiograph a successful marker of chronic heart failure models Ejection fraction 〈 60% was considered to be However, the left anterior descending coronary artery was not ligated in the sham operation group. The GHRP group was injected with 100 μ g/kg GHRP-2, and the other two groups were injected with the same volume of physiological saline, once per day. MAIN OUTCOME MEASURES： After 4 weeks, pathological changes in cardiac cholinergic nerve fibers were detected under optic microscopy following hematoxylin/eosin staining. In addition, density distribution was measured using a multi-function color pathological image system. RESULTS： In the sham operation group, myocardial cells were regular, uniformly stained, and no inflammatory cells were present. In the model group, myocardial cells were unevenly stained, exhibited nuclear atrophy, degeneration, dissolution, or disappearance. In the GHRP group, myocardial damage was less than in the model group; cardiac muscle fibers exhibited slight degeneration. The myocardium in the sham operation group was serried, spreading the cholinergic innervations along the cardiac fiber. In the model group, there was a decreased number of cholinergic nerve fibers decreased, which also became shorter and smaller, compared with the sham operation group （P 〈 0.01）. In the GHRP group, cholinergic positive nerve fibers were significantly increased compared with the model group （P 〈 0.01）, but still less than the sham surgery group （P 〈 0.05）. CONCLUSION： GHRP delayed denervation and reduced nerve reconstitution following heart failure in rats.

Growth hormone receptor expression in human primary gastric adenocarcinoma

The aim of this study was to determine the expression of growth hormone receptor（GHR） in patients with pri-mary gastric adenocarcinoma.We investigated 48 specimens of primary gastric adenocarcinoma and their cor-responding normal gastric mucosa.Immunohistochemistry and reverse transcription-polymerase chain reaction（RT-PCR） were used to detect the expression of GHR.Immunohistochemical analyses revealed that GHR was expressed in human primary gastric adenocarcinoma（36/48,75.0%） and appeared to be upregulated,compared to the normal mucosa（28/48,58.3%,P 〈 0.001）.A significant correlation was found between GHR expression and tumor stage（P 〈 0.001） and tumor differentiation（P 〈 0.001）.The average positive rate of ki-67 in GHR-positive tumors was 16.06%,while the positive rate in GHR-negative tumors was 6.17%（P 〈 0.01）.The average apoptosis index（AI） of GHR-positive tumors was 3.36%,which was significantly lower than that（7.33%） of GHR-negative tumors.In addition,27 of 48 cases of tumors had GHR mRNA expression,while only 17 of all 48 cases of normal mucosa did so.Our results indicate that the frequency of GHR was significantly higher in primary gastric adeno-carcinoma than that in normal gastric mucosa.GHR expression was significantly correlated with tumor differen-tiation and tumor grade.This finding supported a possible role of growth hormone in primary gastric adenocarci-noma pathophysiology.

Identification and sequencing of preprothyrotropin-releasing hormone and its receptor in rat testis

Objective: To investigate the expression regulation of thyrotrophin-releasing hormone (TRH) and its receptor (TRH-R) in rat testis and their function in the reproduction and development. Methods: Total RNA of fat testicular tissues was used as template. The oligonucleotide primers were designed from the sequence of rat hypothalamus prepro(pp)TRH and pituitary TRH-R cDNA for reverse transcription- polymerase chain reaction (RT- PCR ). Specific fragments of ppTRH and TRH-R cDNA were cloned and sequenced. Results: DNA sequence analysis indicated that cDNA Sequences of ppTRH and TRH-R from rat testis were consistent with those of hypothalamus ppTRH and pituitary TRH-R cDNA. Conclusion: TRH may function as a new autocrine or paracrine regulator of testicular function via a transmembrane receptor very similar or identical to that in pituitary.

Immunohistochemical Localization and Receptor Expression of Gonadotropin-Releasing Hormone in Pituitary of Guangxi Swamp Buffaloes

[ Objective] To locate gonadotropin-releasing hormone （GnRH） in pituitary of Guangxi swamp buffaloes and to provide a theoretical ba- sis for cloning and sequence analysis of GnRH receptor gene. [ Method] GnRH in pituitary were immunohistochemically stained by avidin biotin complex method. The GnRH expression was analyzed with image system. The GnRH receptor gene was amplified by real-time PCR. [ Result] Many GnRH positive cells were detected in pars distalis of adenohypophysis. GnRH were distributed in cytoplasm but not in nuclei. No positive sig- nal was observed in neurohypophysis. In addition, the GnRH receptor gene, 920 bp in size, was amplified. [ Conclusion] A large number of GnRH and GnRH receptor were found in pars distalis of adenohypophysis, which indicates that anterior pituitary is an important tissue for functions of hypo- thalamus-pituitary-gonadal axis and other endocrine axes.

The role of endotoxin,TNF-α,and IL-6 in inducing the state of growth hormone insensitivity

AIM: Critical illnesses such as sepsis, trauma, and burns cause a growth hormone insensitivity, which leads to an increased negative nitrogen balance. Endotoxin is generously released into blood under these conditions and stimulates the production of proinflammatory cytokines such as TNF-alpha, IL-6, and IL-1, which may play a very important role in inducing the growth hormone insensitivity. The objective of this current study was to investigate the role of endotoxin, TNF-alpha and IL-6 in inducing the growth hormone insensitivity at the receptor and post-receptor levels. METHODS: Spague-Dawley rats were injected with endotoxin, TNF-alpha, and IL-6, respectively and part of rats injected with endotoxin was treated with exogenous somatotropin simultaneously. All rats were killed at different time points. The expression of IGF-I, GHR, SOCS-3 and beta-actin mRNA in the liver was detected by RT-PCR and the GH levels were measured by radioimmunoassay, the levels of TNF-alpha and IL-6 were detected by ELISA. RESULTS: There was no significant difference in serous GH levels between experimental group and control rats after endotoxin injection, however, liver IGF-I mRNA expression had been obviously down-regulated in endotoxemic rats. Liver GHR mRNA expression also had a predominant down-regulation after endotoxin injection. The lowest regulation of liver IGF-I mRNA expression occurred at 12h after LPS injection, being decreased by 53% compared with control rats. For GHR mRNA expression, the lowest expression occurred at 8h and had a 81% decrease. Although SOCS-3 mRNA was weakly expressed in control rats, it was strongly up-regulated after LPS injection and had a 7.84 times increase compared with control rats. Exogenous GH could enhance IGF-I mRNA expression in control rats, but it did fail to prevent the decline in IGF-I mRNA expression in endotoxemic rats. Endotoxin stimulated the production of TNF-alpha and IL-6, and the elevated IL-6 levels was shown a positive correlation with increased SOCS-3 mRNA expression. The liver GHR mRNA expression was obviously down-regulated after TNF-alpha iv injection and had a 40% decrease at 8h, but the liver SOCS-3 mRNA expression was the 4.94 times up-regulation occurred at 40 min after IL-6 injection. CONCLUSION: The growth hormone insensitivity could be induced by LPS injection, which was associated with down-regulated GHR mRNA expression at receptor level and with up-regulated SOCS-3 mRNA expression at post-receptor level. The in vivo biological activities of LPS were mediated by TNF-alpha and IL-6 indirectly, and TNF-alpha and IL-6 may exert their effects on the receptor and post-receptor levels respectively.

Effect of sericin on diabetic hippocampal growth hormone/insulin-like growth factor 1 axis

Previous studies have shown that sericin extracted from silk cocoon significantly reduces blood glucose levels and protects the nervous system against diabetes mellitus. In this study, a rat type 2 diabetes mellitus model was established by intraperitoneal injection of 25 mg/kg streptozotocin for 3 successive days, following which the rats were treated with sericin for 35 days. After treatment, the blood glucose levels of the diabetic rats decreased significantly, the growth hormone level in serum and its expression in the hippocampus decreased significantly, while the insulin-like growth factor-1 level in serum and insulin-like growth factor-1 and growth hormone receptor expression in the hippocampus increased significantly. The experimental findings indicate that sericin improves disorders of the growth hormone/insulin-like growth factor 1 axis to alleviate hippocampal damage in diabetic rats.

Optimization of the Purification Methods for Recovery of Recombinant Growth Hormone from Paralichthys olivaceus

This study aimed to optimize the purification of recombinant growth hormone from Paralichthys olivaceus. Recombinant flounder growth hormone （r-fGH） was expressed by Escherichia coli in form of inclusion body or as soluble protein under different inducing conditions. The inclusion body was renatured using two recovery methods, i.e., dilution and dialysis. Thereafter, the refolded protein was purified by Glutathione Sepharase 4B affinity chromatography and r-fGH was obtained by cleavage of thrombin. For soluble products, r-fGH was directly purified from the lysates by Glutathione Sepharase 4B affinity chromatography. ELISA-receptor assay demonstrated that despite its low receptor binding activity, the r-fGH purified from refolded inclusion body had a higher yield （2.605 mg L^-1） than that from soluble protein （1.964 mg L^-l）. Of the tested recovery methods, addition of renaturing buffer （pH 8.5） into denatured inclusion body yielded the best recovery rate （17.9%）. This work provided an optimized purification method for high recovery of r-fGH, thus contributing to the application of r-fGH to aquaculture.

Preclinical therapy of benign prostatic hyperplasia with neuropeptide hormone antagonists

Benign prostatic hyperplasia(BPH)is a pathologic condition of the prostate described as a substantial increase in its number of epithelial and stromal cells.BPH may significantly reduce the quality of life due to the initiation of bladder outlet obstruction and lower urinary tract syndromes.Current medical therapies mostly consist of inhibitors of 5α-reductase orα1-adrenergic blockers;their efficacy is often insufficient.Antagonistic analogs of neuropeptide hormones are novel candidates for the management of BPH.At first,antagonists of luteinizing hormone-releasing hormone(LHRH)have been introduced to the therapy aimed to reduce serum testosterone levels.However,they have also been found to produce an inhibitory activity on local LHRH receptors in the prostate as well as impotence and other related side effects.Since then,several preclinical and clinical studies reported the favorable effects of LHRH antagonists in BPH.In contrast,antagonists of growth hormone-releasing hormone(GHRH)and gastrin-releasing peptide(GRP)have been tested only in preclinical settings and produce significant reduction in prostate size in experimental models of BPH.They act at least in part,by blocking the action of respective ligands produced locally on prostates through their respective receptors in the prostate,and by inhibition of autocrine insulin-like growth factors-Ⅰ/Ⅱand epidermal growth factor production.GHRH and LHRH antagonists were also tested in combination resulting in a cumulative effect that was greater than that of each alone.This article will review the numerous studies that demonstrate the beneficial effects of antagonistic analogs of LHRH,GHRH and GRP in BPH,as well as suggesting a potential role for somatostatin analogs in experimental therapies.

ENDOCRINE CHANGES OF PARALICHTHYS OLIVACEUS AFTER ORAL ADMINISTRATION WITH EXOGENOUS GROWTH HORMONE

Recombinant salmon growth hormone contained in yeast was given for 5 months to flounder in its diet. Both free and total specific binding sites for the growth hormone were examined in liver membranes of control and treated fish. The association constants of both free and total specific binding sites were of the same order (1 nM 1 ), and no significant difference was found between any two groups in the capacity of their free binding sites. The capacity of total binding sites in the liver of treated fish increased significantly compared with that of control. Insulin like growth factor I (IGF I) levels in the plasma of treated fish increased by 22.61% (P<0.05), compared with that of control. While the T 4 levels in plasma did not increase significantly (from 1.35±0.91 ng/ml to 2.29±1.13 ng/ml), T 3 levels were elevated significantly (from 1.78±1.14 ng/ml to 4.87±1.22 ng/ml, P<0.01), as compared with that of control.

Kisspeptin regulates gonadotropin-releasing hormone secretion in gonadotropin-releasing hormone/enhanced green fluorescent protein transgenic rats

Kisspeptin is essential for activation of the hypothalamo-pituitary-gonadal axis. In this study, we established gonadotropin-releasing hormone/enhanced green fluorescent protein transgenic rats. Rats were injected with 1, 10, or 100 pM kisspeptin-10, a peptide derived from full-length kisspeptin, into the arcuate nucleus and medial preoptic area, and with the kJsspeptJn antagonist peptJde 234 into the lateral cerebral ventricle. The results of immunohistochemical staining revealed that pulsatile luteinizing hormone secretion was suppressed after injection of antagonist peptide 234 into the lateral cerebral ventricle, and a significant increase in luteinizing hormone level was observed after kisspeptin-10 injection into the arcuate nucleus and medial preoptic area. The results of an enzyme-linked immunosorbent assay showed that luteinizing hormone levels during the first hour of kisspeptin-10 infusion into the arcuate nucleus were significantly greater in the 100 pM kisspeptin-10 group than in the 10 pM kisspeptin-10 group. These findings indicate that kisspeptin directly promotes gonadotropin-releasing hormone secretion and luteinizing hormone release in gonadotropin-releasing hormone/enhanced green fluorescent protein transgenic rats. The arcuate nucleus is a key component of the kisspeptin-G protein-coupled receptor 54 signaling pathway underlying regulating luteinizing hormone pulse secretion.

Stimulating effect of thyroid hormones in peripheral nerve regeneration:research history and future direction toward clinical therapy

Injury to peripheral nerves is often observed in the clinic and severe injuries may cause loss of motor and sensory functions.Despite extensive investigation,testing various surgical repair techniques and neurotrophic molecules,at present,a satisfactory method to ensuring successful recovery does not exist.For successful molecular therapy in nerve regeneration,it is essential to improve the intrinsic ability of neurons to survive and to increase the speed of axonal outgrowth.Also to induce Schwann cell phenotypical changes to prepare the local environment favorable for axonal regeneration and myelination.Therefore,any molecule that regulates gene expression of both neurons and Schwann cells could play a crucial role in peripheral nerve regeneration.Clinical and experimental studies have reported that thyroid hormones are essential for the normal development and function of the nervous system,so they could be candidates for nervous system regeneration.This review provides an overview of studies devoted to testing the effect of thyroid hormones on peripheral nerve regeneration.Also it emphasizes the importance of combining biodegradable tubes with local administration of triiodothyronine for future clinical therapy of human severe injured nerves.We highlight that the local and single administration of triiodothyronine within biodegradable nerve guide improves significantly the regeneration of severed peripheral nerves,and accelerates functional recovering.This technique provides a serious step towards future clinical application of triiodothyronine in human severe injured nerves.The possible regulatory mechanism by which triiodothyronine stimulates peripheral nerve regeneration is a rapid action on both axotomized neurons and Schwann cells.