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.

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.

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.

Study on pig growth hormone gene polymorphisms in western meat-type breeds and Chinese local breeds

Chinese Meishan and Jiangquhai pigs are two of the most prolific pigs in the world, but their growth rate is lower than that of Duroc, Landrace and Pietrain pigs. It is suggested that growth rate is regulated by growth hormone. The objective of the current study was to analyze the porcine growth hormone (p GH ) gene polymorphisms based on the polymerase chain reaction restriction fragment length polymorphism method (PCR RFLP) for three western meat type breeds (Duroc, Landrace and Pietrain) and two local Chinese pigs (Meishan and Jiangquhai). Five polymorphic restriction sites were detected with the Apa I, Msp I, Bsp I and Hha I restriction enzymes in two amplified fragments (605 bp, -119 to +486; 506 bp, +206 to +711). Breed difference was found only in the 506 bp fragment. There was no difference in allelic frequencies of Bsp I and Hha I restriction sites among the five breeds ( P >0.05). Landrace and Meishan pigs lacked allele G 3 of Msp I site. The allele G 3 frequency of restriction Msp I site of the 506 bp fragment in Pietrain pigs was higher than that in Duroc and Jianquhai pigs ( P <0.001). For Apa I site, the Meishan pigs lacked allele G1 ; no difference was found in allelic frequencies among Pietrain, Duroc, Landrace and Jiangquhai pigs ( P > 0.05 ). This new and rapid PCR RFLP typing method is an attractive tool for analysis of porcine growth hormone gene restriction sites. The differences in Msp I and Apa I restriction sites may explain the growth difference between the foreign meat type breeds above mentioned and local Chinese pigs.

EFFECT OF INTERLEUKIN-1β ON GROWTH HORMONE GENE EXPRESSION AND ITS POSSIBLE MOLECULAR MECHANISM IN RAT MtT/S SOMATOTROPH CELLS

Objective To elucidate the effect of interleukin-1β （IL- 1β） on human growth hormone （hGH） gene expression in a rat somatotropic pituitary cell line MtT/S. Methods Stably transfected MtT/S cells were firstly established by transfecting 484-Lucl plasmid which contained hGH gene promoter --484 to ＋30 bp and luciferase reporter gene. The effect of IL-1β on hGH gene expression was determined by assaying the luciferase activities. RT-PCR method was also used to determine whether IL-1 recepor mRNA was expressed in MtT/S cells. Results The 10^3 U/mL IL-1β stimulated secretion and synthesis of GH, and promoted the 5＇-promoter activity of GH gene in stably transfected MtT/SGL cells with the action of 1.38 times above the control. Among inhibitors of signaling transduction pathways, mitogen-activated protein kinase kinase （MAPKK/MEK） inhibitor PD98059 （40 μmol/L） and p38 mitogen-activated protein kinase （MAPK） inhibitor SB203580 （5 μmol/L） completely blocked the stimulatory effect of IL-1μ, and phosphatidylinositol-3-kinase （PI3-K） inhibitor LY294002 partly abolished the effect of IL-1μ. Western blot analysis further confirmed the activation of phosphorylated MEK and p38 MAPK in MtT/SGL cells. Neither over-expression of Pit- 1 nor inhibition of Pit- 1 expression affected induction of hGH promoter activity by IL-1μ. A series of deletion constructs of hGH promoter were created to identify the DNA sequence that mediated the effect of IL-1β, and results showed that the stimulatory effect of IL-1β was abolished following deletion of the --196 to -- 132 bp fragment. Conclusions IL-1β promotes GH secretion and synthesis in rat MtT/S somatotroph cells. The stimulatory effect of IL-1β on hGH gene promoter appears to require the activation of MEK, p38 MAPK, PI3-K, and a fragment of promoter sequence that spans the -196 to -132 bp of the gene, but it may be unlinked with Pit-1 protein.

MEK AND p38 MAPK-DEPENDANT PATHWAYS ARE INVOLOVED IN THE POSITIVE EFFECT OF INTERLEUKIN-6 ON HUMAN GROWTH HORMONE GENE EXPRESSION IN RAT MtT/S SOMATOTROPH CELLS

Objective To investigate the effect of interleukin-6(IL-6)on the human growth hormone(hGH)gene expression in a rat somatotropic pituitary cell line MtT/S.Methods The plasmids containing various lengths of hGH gene 5'-promoter fragments were constructed.Stably transfected MtT/S cells were created by cotransfecting the above plasmids and pcDNA3.1(+)with DMRIE-C transfection reagent.After the administration of these cells with IL-6 and/or various inhibitors of signaling transduction pathways,the luciferase activities in MtT/S cells lysis were assayed to demonstrate the effects of IL-6 on hGH gene promoter activity and possibly involved mechanism.Results The 103 U/mL IL-6 stimulated GH secretion and synthesis,and promoted the 5'-promoter activity of GH gene in stably transfected MtT/SGL cells with the action of 1.69 times above the control.Among inhibitors of signaling transduction pathways,mitogen-activated protein kinase kinase(MAPKK/MEK)inhibitor PD98059(40 μmol/L)and p38 mitogen-activated protein kinase(MAPK)inhibitor SB203580(5 μmol/L)completely blocked the stimulatory effect of IL-6.Western blot analysis further confirmed the activation of phosphorylated MEK and p38 MAPK in MtT/SGL cells.Neither over-expression of Pit-1 nor inhibition of Pit-1 expression affected IL-6 induction of hGH promoter activity.A series of deletion constructs of hGH promoter were created to identify the DNA sequence that mediated the effect of IL-6.The results showed that the stimulatory effect of IL-6 was abolished following deletion of the-196 to-132 bp fragment.Conclusions IL-6 promotes GH secretion and synthesis by rat MtT/S somatotroph cells.The stimulatory effect of IL-6 on hGH gene promoter appears to require the activation of MEK and p38 MAPK,and a fragment of promoter sequence that spans the-196 to-132 bp of the gene,but may be unlinked with Pit-1 protein.

Association of growth rate with hormone levels and myogenic gene expression profile in broilers

Background： The growth rate often varies among individual broilers of the same breed under a common management condition. To investigate whether a variation in the growth rate is associated with a difference in hormone levels and myogenic gene expression profile in broilers, a feeding trial was conducted with 10,000 newly hatched Ross 308 chicks in a commercial production facility under standard management. At 38 d of age,30 fast-, 30 medium-, and 30 slow-growing broilers were selected among 600 healthy male individuals. The levels of insulin-like growth factor-1（IGF-1）, triiodothyronine（T3）, thyroxine（T4）, and growth hormone in the serum or breast muscle were assayed by ELISA or RIA kits, and the expression levels of several representative pro-and anti-myogenic genes in the breast muscle were also measured by real-time PCR.Results： Results showed that both absolute and relative weights of the breast muscle were in linear positive correlations with the body weight of broilers（P 〈 0.001）. Fast-growing broilers had higher concentrations of IGF-1 than slow-growing broilers（P 〈 0.05） in both the serum and breast muscle. The serum concentration of T3 was significantly higher in fast-growing birds than in slow-growing birds（P 〈 0.05）. However, no difference was observed in growth hormone or T4 concentration among three groups of birds. Additionally, a decreased expression of an anti-myogenic gene（myostatin） and increased expressions of pro-myogenic genes such as myogenic differentiation factor 1, myogenin, muscle regulatory factor 4, myogenic factor 5, IGF-1, and myocyte enhancer factor 2B, C, and D were observed in fast-growing broilers（P 〈 0.05）, relative to slow-growing broilers.Conclusions： Collectively, these findings suggested that the growth rate is linked to the hormone and myogenic gene expression levels in broiler chickens. Some of these parameters such as serum concentrations of IGF-1 and T3 could be employed to breed for enhanced growth.

Molecular cloning and analysis of the partial sequence of Rhinopithecus roxellanae growth hormone gene

Growth hormone gene (GH) ofRhinopithecus roxellanae was amplified by PCR based on the sequences of the reported mammalian growth hormone gene for the first time. The amplified fragment was about 1.8 kb. It was cloned and its upper stream was sequenced. This sequencing region consists of a 5′flanking regulatory region, exon I and part of exon II, intron I of growth hormone gene. Comparing the corresponding sequences of growth hormone gene betweenRhinopithecus roxellanae and the porcine, we concluded that the homology reached 81% in the region, and there was high conservation in the 5′flanking sequence. The kinds of amino acids of exon I and exon II for about 90% were the same to those in pig. Many mutations occurred in the degenerate site of the triplet code. In the nucleotides of intron I, there were only 72% homologies with those in pig. It means that introns and 3′flanking sequence maybe play an important part in growth hormone gene regulation of the different animals.

Stocking density affects the growth performance and metabolism of Amur sturgeon by regulating expression of genes in the GH/IGF axis

The effects of stocking density on the growth and metabolism of Amur sturgeon were assessed. Amur sturgeon were grown for 70 days at three dif ferent stocking densities(low stocking density, LSD: 5.5 kg/m^3; medium stocking density, MSD: 8.0 kg/m^3; and high stocking density, HSD: 11.0 kg/m^3), and the biometric index, muscle composition, and serum biochemical parameters were evaluated. In addition, pituitary, liver, and muscle samples were collected for gene cloning and expression analyses. After 70 days of growth, the fish maintained at HSD had significantly lower fi nal body weight and specifi c growth rate, and a higher feed conversion ratio than those of the fish in the MSD and LSD groups. The HSD group had the lowest lipid and protein concentrations in serum and muscle. The serum cortisol concentration increased significantly in the HSD group, indicating that the stress-response system was activated in these fish. There was no change in the concentration of serum insulin-like growth factor 2(IGF-2), while the concentrations of serum growth hormone(GH) and insulin-like growth factor 1(IGF-1) decreased in the HSD group. The full-length cDNAs of G H and IGF-2 genes(995-bp and 1 207-bp long, respectively), were cloned and analyzed. In the HSD group, the expressions of GH in the pituitary and growth hormone receptor( GHR) and IGF-1 in the liver were down-regulated at the end of the 70-day experiment. In the HSD group, the transcript level of IGF-2 significantly decreased in the liver, but did not change in muscle. Overall, our results indicated that a HSD negatively af fects the growth performance and leads to changes in lipid and protein metabolism in Amur sturgeon. The down-regulated expression of genes related to the GH/IGF axis may be responsible for the poor growth performance of Amur sturgeon under crowding stress.

Growth hormone therapy for children with KBG syndrome:A case report and review of literature

BACKGROUND The incidence of short stature in KBG syndrome is relatively high.Data on the therapeutic effects of growth hormone(GH)on children with KBG syndrome accompanied by short stature in the previous literature has not been summarized.CASE SUMMARY Here we studied a girl with KBG syndrome and collected the data of children with KBG syndrome accompanied by short stature from previous studies before and after GH therapy.The girl was referred to our department because of short stature.Physical examination revealed mild dysmorphic features.The peak GH responses to arginine and clonidine were 6.22 and 5.40 ng/mL,respectively.The level of insulin-like growth factor 1(IGF-1)was 42.0 ng/mL.Genetic analysis showed a c.2635 dupG(p.Glu879fs)mutation in the ANKRD11 gene.She received GH therapy.During the first year of GH therapy,her height increased by 0.92 standard deviation score(SDS).Her height increased from-1.95 SDS to-0.70 SDS after two years of GH therapy.There were ten children with KBG syndrome accompanied by short stature who received GH therapy in reported cases.Height SDS was improved in nine(9/10)of them.The mean height SDS in five children with KBG syndrome accompanied by short stature increased from-2.72±0.44 to-1.95±0.57 after the first year of GH therapy(P=0.001).There were no adverse reactions reported after GH treatment.CONCLUSION GH treatment is effective in our girl and most children with KBG syndrome accompanied by short stature during the first year of therapy.

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.

Understanding Growth Hormone Secretion and Short Stature

Short stature is a clinical challenge in the daily practice of pediatric endocrinology, regarding the several technical, cultural and economic factors associated with its approach. This article intends to review the physiology of growth hormone secretion, the endocrine regulation of human growth and the clinical aspects of the diagnosis and treatment of short stature. It specifically analyses the treatment of short stature with growth hormone, along with its side effects, cost/benefit analysis and possible risks. A clinical case from a medical school is also described, intending a better understanding of this frequent ambulatory situation in endocrinology and pediatrics.

Analysis on Polymorphisms of GHR Gene in Improved Hybrid Yellow Cattle Groups from Liupan Mountain Area in Ningxia

[Objective] The paper aimed to analyze the polymorphism of the growth hormone receptor （GHR） in improved hybrid yellow cattle group from Liupan Mountain area in Ningxia Autonomous Region,so as to provide technological basis for hybrid improvement. [Method] Polymerase chain reaction-restriction fragment length polymorphisms （PCR-RFLP） technology was carried out to examine polymorphisms of GHR gene of 70 individuals. [Result] The target fragment of 338 bp was amplified. The PCR product digested by restriction enzyme Alu I showed polymorphisms. The frequencies of the two genotypes （AA,BB） were 75.71% （53 individuals） and 24.29% （17 individuals）,respectively. [Conclusion] Two genotypes of GHR gene were detected in improved hybrid yellow cattle groups from Liupan Mountain area in Ningxia.

Construction of Eukaryotic Expression Vector for Pig Ghrelin Gene

[Objective] This study aimed to investigate the functions of transgenic growth related gene in pig growth. [Method] A pair of primers containing Nhe I and Hind Ⅲ restriction sites were designed by referring to the pig Ghrelin mRNA sequence published in Genbank. Total RNA was extracted from the small intestine tissue of 13/17 Robertson translocation heterozygous pig, and then was purified and used as the template in later RT-PCR reaction to amplify the full-length pig Ghrelin gene. The correct pig Ghrelin gene fragment was cloned into the pMD19-T simple vector for sequencing analysis. The obtained full-length cDNA of pig Ghrelin gene fragment was digested with both Nhe I and Hind Ⅲ, and then was linked into the eukaryotic expression vector pEGFP-N1 to obtain the recombinant plasmid pEGFPGhrelin. The recombinant plasmid was transected into the fibroblast cells to detect the fluorescence labeled gene expression. [Result] The nucleotide sequence extracted from 13/17 Robertson translocation heterozygous pig was the same as expected; and the eukaryotic expression vector pEGFP-Ghrelin was successfully constructed. [Conclusion] The eukaryotic expression vector constructed in this study can be further used in research on transgenic pigs, but also lays foundation for research on the regulatory mechanism of Ghrelin gene.

GH基因SNPs与宁都黄鸡睾丸性状的关联分析

为探索生长激素基因(Growth hormone,GH)部分序列单核苷酸多态位点及其单倍型对宁都黄公鸡睾丸性状的影响,寻找地方鸡种睾丸性状选育的分子标记,试验选取499只16周龄宁都黄公鸡为研究材料,采用PCR直接测序法筛选GH基因5′-flanking和内含子1区域的单核苷酸多态性(Single nucleotide polymorphism,SNP)位点,利用SAS(Statistical analysis system)分析睾丸性状关联的SNP位点,利用PHASE软件对多态位点进行单倍型分析,并使用在线软件对关联位点的转录因子结合类型进行预测。结果显示:GH基因上游序列存在6个多态性位点,即T1272755C、G1272611A、C1272225T、C1271211T、C1271025A和A1271024C,均对睾丸性状的影响达到显著水平(P<0.05);与睾丸性状相关的优势基因组合为TGCCAC/TGCTAC;转录因子预测结果显示在一些转录因子的结合位点会随着等位基因变异而发生特异性变化,如AR(Androgen receptor)、PR(Progesterone receptor)、Sox2(sex determining region Y-box 2)、SRY(Sex determining region Y)、HNF-3beta(Hepatocyte nuclear factor 3-beta)等。研究表明C1271211T为宁都黄鸡睾丸性状的关键候选分子标记,CC基因型个体的睾丸性状显著高于TT型,推测原因为上述5种转录因子之间相互作用,调控GH表达,共同影响睾丸性状。

宁都黄鸡GH基因SNP与鸡冠性状的关联分析

【目的】研究宁都黄鸡GH基因(Growth hormone,GH)5’-侧翼和内含子1区域单核苷酸多态性(Single nucleotide polymorphism,SNP)与鸡冠性状的关联性,以期筛选地方鸡种鸡冠性状的早期选育分子标记。【方法】以499只宁都黄鸡公鸡为研究对象,测定7个不同周龄的冠高、冠长、冠厚、肉垂长、肉垂厚以及冠齿数指标,利用SAS(Statistical analysis system)分析GH基因部分序列SNP与鸡冠性状的关联性。【结果】有13个SNP与冠高性状指标显著关联(P<0.05),即C1272225T、G1272611A、C1271211T、C1270902T、A1270769G、G1270640C、T1270578C、G1270503C、T1270451C、C1270032T,其中A1270769G与7个周龄冠高指标均显著关联;G1272611A与5个周龄冠高指标显著关联;有10个SNP与冠长性状显著关联(P<0.05),即C1272225T、G1272611A、C1271211T、C1270902T、A1270769G、G1270640C、T1270578C、G1270503C、T1270451C、C1270032T,其中C1271211T与6个周龄冠长指标显著关联,G1272611A与5个周龄冠长指标显著关联。G1272611A位点与5个连续周龄冠长或冠高性状指标均显著关联,该位点在该群体中对应GG和GA 2种基因型,GG基因型个体的5个连续周龄冠高或冠长均显著高于GA基因型个体。【结论】G1272611A位点可作为宁都黄鸡冠高和冠长性状选育重要候选分子标记。

Developmental Changes of GHR Gene Expression in Multiple Tissues of Mink

[Objective] The paper was to explore the changes of GHR gene expression in different tissues of mink.[Method] With American mink as the research object, the expression volumes of GHR gene in heart, liver, spleen, lung, kidney, intestine and skin tissues at different growth stages(45, 90, 120, 150 and 180 days of age) were detected by real-time PCR, and comparative analysis was performed.[Result] The GHR gene expressions in heart, liver and spleen tissues at 180 days of age were extremely higher than those at other days of age( P<0.01). The GHR gene expression in lung tissue at 120 days of age was extremely higher than those at other days of age( P<0.01). The GHR gene expressions in intestine tissue at 45 and 120 days of age were extremely higher than those at other days of age(P<0.01), but no significant difference was observed between 45 and 120 days of age(P>0.05). The GHR gene expression in kidney tissue at 150 days of age was significantly higher than those at other days of age( P<0.05).The GHR gene expression in skin tissue was extremely higher than that those at other days of age( P<0.01). The GHR gene expressions in intestinal tissue at 45 and 120 days of age were extremely higher than those in other tissues(P<0.01). The GHR gene expressions in skin tissue at 90 days of age was extremely higher than those in other tissues(P<0.01). The GHR gene expressions in intestine, spleen and kidney tissues at 150 days of age were extremely higher than those in other tissues(P<0.01). The GHR gene expressions in spleen tissue at 180 days of age was extremely higher than those in other tissues(P<0.01).[Conclusion] The expression of GHR gene in mink showed obvious spatio-temporal specificity.

THE ROLE OF CALCIUM ION IN THE PATHOGENESIS OF HUMAN PITUITARY GH－SECRETING ADENOMAS

To study the role of Ca2+ in the pathogenesis of pituitary growth hormone secreting adenomas, the function of Ca2+ in 23 cases of human Prturtary GH-secreting adenoma was investigated in monolayer cell culture. It was found that Ca2+ channel blockers nicardipin and nifedipin inhibrted basal and growth hormone releasing hormone (GRH)stimulated GH secretion in 87. 5 % and 100. 0 % of the GH adenomas . respectively, demonstrating that in most human pituitary GH adenomas, the basal and GRH regulated GH secretion is Ca2+ dependent. The GRH and sometostatin (SRIF) agonist octreotide regulated the processes of GH secretion via Ca2+ had defects in different steps including receptor ,postreceptor Ca2+ channel and Ca2+GH secreting coupling in 6 (66. 6%) and 5 (55. 5 % ) cases of 9 GH adenomas respectively. Among them,the defects in GRH receptor and SRIF regulated Ca2+ channel are the main causes of the dysfunction of GH adenomas. These defects may be related to GH hypersecretion in GH adenomas. Our data provides advance evidences for intrinsic defects of GH adenomas.