Role of bisphosphonates in osteoporosis caused by adult growth hormone deficiency

In recent years,growth hormone and insulin-like growth factors have become key regulators of bone metabolism and remodeling,crucial for maintaining healthy bone mass throughout life.Studies have shown that adult growth hormone deficiency leads to alterations in bone remodeling,significantly affecting bone microarchitecture and increasing fracture risk.Although recombinant human growth hormone replacement therapy can mitigate these adverse effects,improving bone density,and reduce fracture risk,its effectiveness in treating osteoporosis,especially in adults with established growth hormone deficiency,seems limited.Bisphosphonates inhibit bone resorption by targeting farnesyl pyrophosphate synthase in osteoclasts,and clinical trials have confirmed their efficacy in improving osteoporosis.Therefore,for adult growth hormone deficiency patients with osteoporosis,the use of bisphosphonates alongside growth hormone replacement therapy is recommended.

Growth hormone promotes the reconstruction of injured axons in the hypothalamo-neurohypophyseal system

Previous studies have shown that growth hormone can regulate hypothalamic energy metabolism, stress, and hormone release. Therefore, growth hormone has great potential for treating hypothalamic injury. In this study, we established a specific hypothalamic axon injury model by inducing hypothalamic pituitary stalk electric lesions in male mice. We then treated mice by intraperitoneal administration of growth hormone. Our results showed that growth hormone increased the expression of insulin-like growth factor 1 and its receptors, and promoted the survival of hypothalamic neurons, axonal regeneration, and vascular reconstruction from the median eminence through the posterior pituitary. Altogether, this alleviated hypothalamic injury-caused central diabetes insipidus and anxiety. These results suggest that growth hormone can promote axonal reconstruction after hypothalamic injury by regulating the growth hormone-insulin-like growth factor 1 axis.

Growth hormone improves insulin resistance in visceral adipose tissue after duodenal-jejunal bypass by regulating adiponectin secretion

BACKGROUND The mechanism of improvement of type 2 diabetes after duodenal-jejunal bypass(DJB)surgery is not clear.AIM To study the morphological and functional changes in adipose tissue after DJB and explore the potential mechanisms contributing to postoperative insulin sensitivity improvement of adipose tissue in a diabetic male rat model.METHODS DJB and sham surgery was performed in a-high-fat-diet/streptozotocin-induced diabetic rat model.All adipose tissue was weighed and observed under microscope.Use inguinal fat to represent subcutaneous adipose tissue(SAT)and mesangial fat to represent visceral adipose tissue.RNA-sequencing was utilized to evaluate gene expression alterations adipocytes.The hematoxylin and eosin staining,reverse transcription-quantitative polymerase chain reaction,western blot,and enzyme-linked immunosorbent assay were used to study the changes.Insulin resistance was evaluated by immunofluorescence.RESULTS After DJB,whole body blood glucose metabolism and insulin sensitivity in adipose tissue improved.Fat cell volume in both visceral adipose tissue(VAT)and SAT increased.Compared to SAT,VAT showed more significantly functional alterations after DJB and KEGG analysis indicated growth hormone(GH)pathway and downstream adiponectin secretion were involved in metabolic regulation.The circulating GH and adiponectin levels and GH receptor and adiponectin levels in VAT increased.Cytological experiment showed that GH stimulated adiponectin secretion and improve insulin sensitivity.CONCLUSION GH improves insulin resistance in VAT in male diabetic rats after receiving DJB,possibly by increasing adiponectin secretion.

Effect of growth hormone on colonic anastomosis after intraperitoneal administration of 5-fluorouracil, bleomycin and cisplatin: An experimental study

BACKGROUND Growth hormone(GH)plays a crucial role in wound healing and tissue repair in postoperative patients.In particular,colonic anastomosis healing following colorectal surgery is impaired by numerous chemotherapy agents.AIM To investigate whether GH can improve the healing of a colonic anastomosis following the adverse effects of intraperitoneal administration of 5-fluorouracil(5-FU),bleomycin and cisplatin.METHODS Eighty Wistar rats underwent laparotomy and a 1 cm-resection of the transverse colon,followed by an end-to-end anastomosis under general anesthesia.The rats were blindly allocated into four equal groups and administered a different daily intraperitoneal therapeutic regimen for 6 days.The control group(A)received normal saline.Group B received chemotherapy with 5-FU(20 mg/kg),bleomycin(4 mg/kg)and cisplatin(0.7 mg/kg).Group C received GH(2 mg/kg),and group D received the aforementioned combination chemotherapy and GH,as described.The rats were sacrificed on the 7th postoperative day and the anastomoses were macroscopically and microscop-ically examined.Body weight,bursting pressure,hydroxyproline levels and inflammation markers were measured.RESULTS All rats survived until the day of sacrifice,with no infections or other complications.A decrease in the body weight of group D rats was observed,not statistically significant compared to group A(P=1),but significantly different to groups C(P=0.001)and B(P<0.01).Anastomotic dehiscence rate was not statistically different between the groups.Bursting pressure was not significantly different between groups A and D(P=1.0),whereas group B had a significantly lower bursting pressure compared to group D(P<0.001).All groups had significantly more adhesions than group A.Hydroxyproline,as a measurement of collagen deposition,was significantly higher in group D compared to group B(P<0.05),and higher,but not statistically significant,compared to group A.Significant changes in group D were recorded,compared to group A regarding inflammation(3.450 vs 2.900,P=0.016)and fibroblast activity(2.75 vs 3.25,P=0.021).Neoangiogenesis and collagen deposition were not signifi-cantly different between groups A and D.Collagen deposition was significantly increased in group D compared to group B(P<0.001).CONCLUSION Intraperitoneal administration of chemotherapy has an adverse effect on the healing process of colonic anastomosis.However,GH can inhibit the deleterious effect of administered chemotherapy agents and induce colonic healing in rats.

Effects of different doses of long-acting growth hormone in treating children with growth hormone deficiency

BACKGROUND With the improvement of economy and living standards,the attention paid to short stature in children has been increasingly highlighted.Numerous causes can lead to short stature in children,among which growth hormone deficiency(GHD)is a significant factor.AIM To investigate the long-term efficacy and safety of different doses of long-acting polyethylene glycol recombinant human growth hormone(PEG-rhGH)in the treatment of GHD in children.METHODS We selected 44 pediatric patients diagnosed with GHD who were treated at Wuhu First People's Hospital from 2014 to 2018.Total 23 patients were administered a high dose of long-acting PEG-rhGH at 0.2 mg/kg subcutaneously each week,forming the high-dose group.Meanwhile,21 patients were given a lower dose of long-acting PEG-rhGH at 0.14 mg/kg subcutaneously each week,establishing the low-dose Group.The total treatment period was 2 years,during which we monitored the patients’height,annual growth velocity(GV),height standard deviation score(HtSDS),chronological age(CA),bone age(BA),and serum levels of insulin-like growth factor-1(IGF-1)and insulin-like growth factor-binding protein-3(IGFBP-3)before treatment and at 6 mo,1 year,and 2 years after treatment initiation.We also monitored thyroid function,fasting plasma glucose,fasting insulin,and other side effects.Furthermore,we calculated the homeostatic model assessment for insulin resistance.RESULTS After 1 year of treatment,the GV,HtSDS,IGF-1,BA,and IGFBP-3 in both groups significantly improved compared to the pre-treatment levels(P<0.05).Moreover,when comparing GV,HtSDS,IGF-1,BA,and IGFBP-3 between the two groups,there were no statistically significant differences either before or after the treatment(P>0.05).During the treatment intervals of 0-1.0 years and 1.0-2.0 years,both patient groups experienced a slowdown in GV and a decline in HtSDS improvement(P<0.05).CONCLUSION The use of PEG-rhGH in treating GHD patients was confirmed to be effective,with similar outcomes observed in both the high-dose group and low-dose groups,and no significant differences in the main side effects.

Growth hormone and gastrointestinal malignancy:An intriguing link

Growth hormone(GH)excess is associated with several systemic complications,one of which is the increased risk of neoplastic processes particularly of the gastrointestinal(GI)tract.Among the GI neoplasms,the most reported association is with benign and malignant neoplasms of the colon.In the majority of published literature,an increased incidence of GI neoplasms,both colonic adenomas as well as colorectal carcinoma is reported.However,the studies on colon cancer-specific mortality rate are conflicting with recent studies reporting similar cancer-specific mortality rates in comparison to controls.Many studies have reported an association of colorectal neoplasms with GH levels.Pathogenic mechanisms put forward to explain this association of GH excess and GI neoplasms primarily involve the increased GH-insulin-like growth factor 1(IGF-1)signaling.Both GH and IGF-1 have proliferative,anti-apoptotic,and angiogenic effects on the systemic tissues leading to cellular proliferation.Other contributing factors to the increased risk of GI neoplasms include slow intestinal transit with a redundant large bowel,altered bile acids,deranged local immune response,shared genetic susceptibility factors and hyperinsulinemia.In view of the increased risk association,most guidelines for the care of acromegaly patients recommend an initial screening colonoscopy.Recommendations for further follow-up colonoscopy differ but broadly,the guidelines agree that it depends on the findings at first colonoscopy and state of remission of GH excess.Regarding the concern about the risk of colorectal cancers in patients receiving recombinant GH therapy,most cohort studies do not show an increased risk.

Salt Stress Affects the Growth and Yield of Wheat (Triticum aestivum L.) by Altering the Antioxidant Machinery and Expression of Hormones and Stress- Specific Genes

Understanding physiological responses in saline agriculture may facilitate wheat breeding programs.Based on a screening test,the Ningmai-14(NM-14)and Yangmai-23(YM-23)wheat cultivars were selected for further experiments to understand the underlying salinity tolerance mechanism.This study investigated the effects of five salinity levels such as Control(CK)=0(without NaCl stress),S1=0.20%,S2=0.25%,S3=0.30%and S4=0.35%of NaCl concentrations of soil on wheat plants.The results showed that increased salinity concentration reduced the growth and yield of wheat cultivars(NM-14 and YM-23).However,YM-23(12.7%)yielded more than NM-14 at maximum salinity stress.The higher salinity(S4)increased the concentration of Na^(+)(4.3 to 5.8-fold)and P contents(2.5 to 2.2-fold),while reducing the average concentrations of K^(+),Cu,and K^(+)/Na^(+)ratio.The higher salinity(S4)reduced the spikelet length by 21.35%(followed by grain spike−1),and the starch content by 18.81%.In the YM-23 cultivar,higher salinity increased superoxide dismutase(SOD),total antioxidant capacity(TAC),and amylase.Compared to NM-14,induced expression of TaYUC2,6,and TaGA13ox,20ox genes were recorded in YM-23.Similarly,in YM-23 the stress-specific genes such as TaHSP70,90 were enhanced whereas,TaSOS1,2 were suppressed.Overall,our study revealed that salt tolerant cultivars modulate hormonal and antioxidant activities,thus maintaining high 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.

GHRP-6 Induces CREB Phosphorylation and Growth Hormone Secretion via a Protein Kinase Cσ-dependent Pathway in GH3 Cells

This study examined the effect of GHRP-6, a known GHSs receptor agonist, on the phosphorylation of cAMP-responsive element-binding protein （CREB） and the tmderly mechanism. GH3 cells were cultured and subjected to different treatments as follows： GHRP-6, GHRP-6 plus GHRH, phorbol ester （PMA）, an activator of PKC, alone or in combination with GHRP-6, G66983, a general inhibitor of PKCs, in the presence or absence of GHRP-6, rottlerin, an inhibitor of PKCs, alone or plus GHRP-6. The cells were transiently transfected with PKCσ-specific siRNA and then treated with GHRP-6. GH level was measured by enzyme-linked immunosorbent assay （ELISA）. The expression of phosphor-CREB, PKCσ, PKC0 and phosphor-PKCo was determined by Western blotting. The results showed that GHRP-6 stimulated GH secretion in both time- and dose-dependent manners and enhanced the effect of GHRH on GH secretion. GHRP-6 was also found to induce CREB phosphorylation. Moreover, GH secretion was enhanced by the PKC activator PMA and reduced by the PKC inhibitors （G66983, rottlerin） and knockdown of PKCσ. PKCσ could be activated by GHRP-6. It is concluded that PKC, especialiy PKCσ, mediates CREB phosphorylation and GHRP-6-induced GH secretion.

Analysis of SNPs in the Promoter Region of the Growth Hormone(GH) Gene in Mini-pigs

Single nucleotide polymorphisms(SNPs) of the growth hormone(GH) gene were investigated in six pig breeds,consisting of four mini-pig breeds(Wuzhishan,Bama,Xiang and Tibet pig),and two others(Dahlan and Landrace pig).Three pairs of primers for promoter regions of the GH gene were designed on the basis of the pig genomic sequence and SNPs were detected by the PCR-SSCP method.The results indicated three mutations in the 5’-flanking region.The analysis results showed that the frequencies of allele A and D in four mini-pig breeds were higher than that in other breeds at a locus within the 5’-flanking region(P【0.05).These results suggest that differences in body size may be associated with these SNPs of 5’-flanking region and amino acid mutation of the signal peptide of GH in these pig breeds.

Changes in Serum Leptin Levels during r-hGH Treatment in Growth Hormone-Deficient Children

To observe the effect of growth hormone on serum leptin levels, serum leptin concentrations were measured by enzyme immunoassay in 12 prebutal children with growth hormone deficiency 1, 3 and 6 months before and after the treatment with recombinant human growth hormone (r hGH). For comparison, 34 normal prepubertal children were also investigated. Relationship between leptin levels and body mass index (BMI) was observed at the same time. Our results showed that serum leptin level in normal prepubertal children was 1.22±0.34 ng/ml; the pretreatment serun leptin levels in GHD children was 3.08±2.41 ng/ml, which was significantly different from those 1, 3 and 6 months after GH treatment (i.e. 1.64±1.37 ng/ml,1.57±1.40 ng/ml and 1.35±0.89 ng/ml respectively) (all P <0.001). Our results suggested that r hGH has a suppressive effect on leptin expression.

Construction of Controllable Expression Vector of Mus musculus Growth Hormone (GH) shRNA and Its Gene Si- lencing Efficiency Detection

Growth hormone （GH） is a polypeptide hormone secreted by the pituitary, which promotes animal growth, muscle development, metabolism regulation and other important physiological functions. In this study, a pair of mGH short hairpin RNA （shRNA） was designed according to mouse （ Mus musculus） GH mRNA sequence; pSingle-tTS-mGH shRNA-RFP, an integrated controllable expression vector of mGH shRNA, was constructed successfully. The recombinant vector was transfected into mouse pituitary tumor cell line AtT-20. After addition of doxycyelin （ DOX）, the expression of red fluorescent protein （RFP） was observed un- der a fluorescent microscope. The expression level of mGH in cells was detected by quantitative Realtime PCR （qRT-PCR） and Western blot. After DOX induction, the relative expression level of GH mRNA in cells transfected with GH shRNA was reduced by about 70% compared with that in DOX-free group and other control groups, exhibiting extremely significant differences （P 〈 0.01 ） ; moreover, the relative expression level of GH protein was reduced by about 90% ; the expression level of GH mRNA and GH protein exhibited no significant difference among other groups （P 〉 0.05）. In this study, a controllable expression vector of GH shRNA with high gene silencing efficiency was constructed successfully, which could be used to reveal GH autocfine / paracrine interactions and analyze functions of GH gene in growth, development and disease occurrence of animals by regulating GH expression levels.

Cloning and Bioinformatics Analysis of Donkey Growth Hormone Gene cDNA

[Objective] The paper aimed to study the donkey GH gene features and functions.[Method] A pair of specific PCR primers was designed for cloning the coding sequence of the donkey GH gene from liver tissue.[Result] 706 bp fragment was got by RT-PCR amplification.The sequence included a complete open reading frame and encoded 216 amino acids.The protein encoded by donkey GH gene had seven hydrophobic region,seven transmembrane regions and a signal peptide;it＇s secondary structure had α-helix and irregular curl and three-dimensional solution structure composed of 27-215 amino acids.[Conclusion] GH gene of donkey was very conservative in evolution.The phylogenetic tree constructed basing on CDS sequence is consistent with the results of comparative morphology and comparative physiology.

Cloning and Functional Analysis of the Porcine Growth Hormone Gene Promoter

[Objective] This study aimed to clone the porcine growth hormone gene promoter and determine the core promoter sequences and the cis-acting elements. [Method] Sequence of the 5＇flanking region of porcine growth hormone gene was searched out and downloaded from the NCBI website. According to the targeted se- quence, primers were designed and synthesized for the PCR amplification. The 1 882 bp （-1 821 bp-＋61 bp） fragment was amplified by PCR. Nine promoter frag- ments with different lengths were obtained by genome-walking deletion method and then cloned into luciferase reporter vectors. Relative transcriptional activities of these 5＇ terminal-deleted plasmids in pituitary and non-pituitary cells were determined by transient transfection of the rat pituitary adenoma cell （GH3）, porcine lilac endotheli- um cell （PIEC） and porcrne Kidney-15 （PK15） with the constructed dual-luciferase vectors. [Result] Result of DNA sequencing showed that the 1 882 bp fragment of GH 5＇ promoter was successfully cloned. Nine luciferase reporter gene plasmids were constructed. DuaI-Luciferase reporter assay indicated that the promoter inserted into reporter gene vector had very strong cell specificity. [Conclusion] Porcine growth hormone gene specifically expresses in pituitary cells. The minimal promoter of the porcine growth hormone gene is mapped at the region -110 bp-＋61 bp. Promoter regions 218 bp--110 bp and -429 bp--218 bp contain positive regulatory elements.

淇河鲫生长激素(growth hormone)全长cDNA的克隆与序列分析

用RT-PCR法和3′、5′RACE(Rapid amplification of cDNAends)法从淇河鲫脑垂体RNA克隆出生长激素(Growth hormone,GH)cDNA.此cDNA全长1191 nt(含Poly(A)14 nt),其5′端非编码区长55 nt、阅读框(Open readingframe,OAF)长633 nt,3′端非编码区长503 nt.其推导的GH由210个氨基酸组成,其中氮端前22个氨基酸为信号肽部分.氨基酸序列比较表明:淇河鲫与同目的鲫鱼、鲤鱼、团头鲂和斑马鱼的同源性分别为98.6%,96.2%,91.5%和88.6%;与不同目鱼的胡子鲇和鳗鲡的同源性分别为74.6%和49.5%;与哺乳类的家鼠和人等的同源性低于40%.

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.

Single nucleotide polymorphisms in intron 1 and intron 2 of Larimichthys crocea growth hormone gene are correlated with growth traits

The growth hormone gene (GH) affects animal growth and is a potential target for genetic studies of variation related to growth traits. In this study, we analyzed single nucleotide polymorphisms (SNPs) in GH intron regions and their associations with growth traits in large yellow croaker, Larimichthys crocea, from Zhejiang and Fujian stocks. The results of PCR-single strand conformation polymorphism showed two haplotypes of intron 1, named AA and AB genotypes, in Zhejiang stock. AB exhibited an SNP at position 196 (G A) that was negatively correlated with body height and positively correlated with standard length/body height (P 0.05). Two different genotypes, CC and CD, were identified in intron 2 in Fujian stock, with CD showing an SNP at position 692 (T C). The CD genotype had a significantly positive correlation with both weight and total length (P 0.01). These basic data highlight the potential for using GH as a genetic marker of fish growth in marker assisted selection.

Hepatic steatosis,low-grade chronic inflammation and hormone/growth factor/adipokine imbalance

Non-alcoholic fatty liver disease (NAFLD), a further expression of metabolic syndrome, strictly linked to obesity and diabetes mellitus, is characterized by insulin resistance (IR), elevated serum levels of free fatty acids and fatty infi ltration of the liver, which is known as hepatic steatosis. Hepatocyte apoptosis is a key feature of this disease and correlates with its severity. Free-fatty-acidinduced toxicity represents one of mechanisms for the pathogenesis of NAFLD and hormones, growth factors and adipokines influence also play a key role. This review highlights the various pathways that contribute to the development of hepatic steatosis. Circulating concentrations of inflammatory cytokines are reckoned to be the most important factor in causing and maintaining IR. Low-grade chronic inflammation is fundamental in the progression of NAFLD toward higher risk cirrhotic states.

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.