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.

Effect of recombinant growth hormone on expression of growth hormone receptor, insulin-like growth factor mRNA and serum level of leptin in growing pigs

Sixteen Large White ?Landrace castrated male pigs were allotted into treatment and control group. The treatment group was injected intramuscularly with recombinant porcine growth hormone (rpGH, 4 mg·d-1) and the control group with vehicle for 28 days. Animals were slaugh-tered 4 h after final injection for liver, longissimus dorsi (LD) muscle and blood sampling. Serum concentration of insulin-like growth factor 1 (IGF-I) and leptin were determined by RIA. The total RNA was extracted from tissues to measure the abundance of growth hormone receptor (GHR), IGF-I mRNA by RT-PCR with 18S rRNA internal standard. Results showed that rpGH enhanced the average daily weight gain by 26.1% (P < 0.05), the serum IGF-I concentration by 70.94% (P < 0.01), decreased serum leptin by 34.8% (P < 0.01). The relative abundance of GHR and IGFmRNA in liver were increased by 24.45% (P < 0.05) and 45.30% (P < 0.01), respectively, but no difference of GHR (P > 0.05) and IGF-I mRNA (P > 0.05) in LD between GH treated and control group was found. These results suggest that rpGH can up-regulate hepatic GHR and IGF-I gene expression and improve animal growth. However the effect of rpGH on GHR and IGF-I gene ex-pression are tissue-specific.

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.

绵羊肝脏生长激素受体基因表达的发育性变化研究

[Objective] To detect the expression of liver growth hormone receptor gene （GHR） during the eady development of Kazak sheep and Xinjiang fine-wool sheep, and thus provide information for the research about the early growth and development of sheep. [ Method] With real-time quantitative PCR, the liver GHR mRNA level was separately detected in two varieties of sheep at 2, 30, 60, 90 and 120 days old. Then the data was analyzed with SPSS software. E Result] The liver GHR gene was highly expressed in 2 day-old sheep, but the expression level fell to the lowest point at 30 days old and then rose continuously; the change trend after 30 days old was positively correlated with the cumulative growth curves of sheep （ P 〈0.05） ; GHR mRNA level was lower in Kazak sheep than in Xinjiang fine-wool sheep during 2 -90 days old, but the difference was ex- tremely significant （P 〈0.01 ） only at 2 days old and 90 days old. [ Conclusion] The male Kazak sheep and Xinjiang fine-wool sheep have similar model of developmental changes of liver GHR mRNA and the differences are smaller between these two species; GHR gene may play an important role in the regulation of sheep growth.

The effects of growth hormone on therapy resistance in cancer

Pituitary derived and peripherally produced growth hormone(GH)is a crucial mediator of longitudinal growth,organ development,metabolic regulation with tissue specific,sex specific,and age-dependent effects.GH and its cognate receptor(GHR)are expressed in several forms of cancer and have been validated as an anti-cancer target through a large body of in vitro,in vivo and epidemiological analyses.However,the underlying molecular mechanisms of GH action in cancer prognosis and therapeutic response had been sparse until recently.This review assimilates the critical details of GH-GHR mediated therapy resistance across different cancer types,distilling the therapeutic implications based on our current understanding of these effects.

Sequencing and Analysis of G HR Gene from Genomic DNA Pools of Mink

In order to study the single nucleotide polymorphisms （SNPs） of growth hormone receptor （GHR） gene in mink populations, genomic DNA pools of Minghua black minks and silver-blue minks were constructed, and the 10^th exon of GHR gene was PCR amplified from the two DNA pools and sequenced. The results showed that two SNPs were found at position 209 （T/C） and position 533 （C/A） of the 10^th exon of GHR gene in the two mink populations.

Therapeutic effects of ghrelin and growth hormone releasing peptide 6 on gastroparesis in streptozotocin-induced diabetic guinea pigs in vivo and in vitro

Background Diabetic gastroparesis is a disabling condition with no consistently effective treatment. In normal animals, both ghrelin and its synthetic peptide, growth hormone releasing peptide 6 （GHRP-6）, increase gastric emptying. Thus, we investigated the potential therapeutic significance of ghrelin and GHRP-6 in diabetic guinea pigs with gastric motility disorders. Methods A diabetic guinea pig model was produced by intraperitoneal （i.p.） injection of streptozotocin （STZ, 280 mg/kg）. Diabetic guinea pigs were injected i.p. with ghrelin or GHRP-6 （10-100 μg/kg）, and the effects on gastric emptying were measured after intragastric application of phenol red. The effect of atropine or a growth hormone secretagogue receptor （GHS-R） antagonist, D-Lys^3-GHRP-6, on the gastroprokinetic effects of ghrelin or GHRP-6 （100 μg/kg） was also investigated. Further, the in vitro effects of ghrelin or GHRP-6 （0.01-10 μmol/L） on spontaneous or carbachol-induced contractile amplitude in gastric fundic circular strips taken from diabetic guinea pigs were examined. Growth hormone secretagogue receptor transcripts in the fundic strips of diabetic guinea pigs were detected by reverse transcriptase polymerase chain reaction （RT-PCR）. Results We established a guinea pig model of delayed gastric emptying. Ghrelin （20, 50, or 100 μg/kg） and GHRP-6 （20, 50, or 100 μg/kg） accelerated gastric emptying in diabetic guinea pigs with gastroparesis （n=6, P 〈0.05）. In the presence of atropine, which delayed gastric emptying, ghrelin and GHRP-6 （100 μg/kg） failed to accelerate gastric emptying （n=6, P 〈0.05）. D-Lys^3-GHRP-6 also delayed gastric emptying induced by the GHS-R agonist （n=6, P 〈0.05）. Ghrelin and GHRP-6 increased the carbachol-induced contractile amplitude in gastric fundic strips taken from diabetic guinea pigs （n=6, P〈0.05）. RT-PCR confirmed the presence of GHS-R mRNA in the strip preparations. Conclusions Ghrelin and GHRP-6 increased gastric emptying in diabetic guinea pigs with gastroparesis, potentially, by activating the peripheral cholinergic pathways in the enteric nervous system.