The effects of ovine placental lactogen and bovine growth hormone on hepatic and mammary gene expression in lactating sheep

The ability of ovine placental lactogen (oPL) to bind to the growth hormone receptor (GHR) raises the possibility that oPL may exert a growth hormone (GH)-like action on galactopoiesis. We have compared the effects of treating lactating ewes for 5 days with an equimolar dose (0.1 mg/kg/day, administered as two equal doses 12 hourly) of either bovine growth hormone (bGH) (n = 10), oPL (n = 10) or saline (n = 9) on hepatic and mammary GHR, insulin-like growth factor-I (IGF-I) and IGF-binding protein-3 (IGFBP-3) gene expression and hepatic GHR number. Hepatic GHR and IGFBP-3 mRNA were unaltered by bGH or oPL treatment. Hepatic IGF-I mRNAs increased following bGH (P < 0.05) but not oPL treatment. GHR gene expression was greater in liver compared to mammary gland extracts. There was no effect of either bGH or oPL treatment on mammary GHR, IGF-I or IGFBP-3 mRNA or hepatic GHR number. These studies confirm the galactopoietic effects of bGH in lactating ruminants and suggest that the mechanism of this action is not via increased hepatic GHR number or gene expression. In addition, the increase in hepatic but not mammary IGF-I mRNA with bGH treatment suggests an endocrine action of IGF-I on milk synthesis. These studies also demonstrate that an equimolar dose of oPL is not galactopoietic or somatogenic in the lactating ewe.     

重组人生长激素治疗青春期前生长激素缺乏症的临床观察

目的探讨重组人生长激素（ｒｈＧＨ）对青春期前特发性生长激素缺乏症（ＩＧＨＤ）患者的疗效。方法对３家医院的６３例ＩＧＨＤ以ｒｈＧＨ进行治疗,每晚临睡前皮下注射０．１ＩＵ／ｋｇ共６个月。结果６３例患儿身高平均增加（７．０±１．６）厘米,年生长速度由治疗前的（２．９±０．９）厘米／年,增加到（１４．０±３．２）厘米／年,身高标准差计分（ＳＤＳ）由治疗前的（－４．８±１．７）变为（－３．９±１．６）;体重也明显增加,但对骨龄无明显促进作用。治疗期间有３９．７％的患儿出现亚临床甲状腺功能低减,２２．４％的患儿于注射局部曾出现短暂的红肿或痒等,７．９％的患儿出现血清ＡＬＴ轻度升高,但所有这些现象均未影响患儿体格的线性增长。结论ｒｈＧＨ是治疗ＩＧＨＤ的一种安全、有效的促生长药物。     

Activity of alkylated prolactin and human growth hormone in receptor and cell assays

The disulfide bonds of two lactogenic hormones, ovine prolactin (oPRL) and human growth hormone (hGH), were reduced with dithiothreitol under denaturing conditions and alkylated with iodoacetic acid. The modified hormones were assayed for their ability to bind the plasma membrane-bound receptor for lactogenic hormone found in the rabbit mammary gland. S-Carboxymethylated ovine prolactin (SCM-oPRL) with all six cysteine residues modified had a nearly 300-fold decrease in binding as compared to native oPRL in a competitive binding assay using [125I]ovine prolactin. The S-carboxymethylated human growth hormone (SCM-hGH) had all four of its cysteine residues modified. It showed only a slightly reduced ability to bind the rabbit mammary gland prolactin receptor in a competitive binding assay with [125I]ovine prolactin. The two modified hormones were assayed for their ability to stimulate proliferation of the lactogen-dependent Nb 2 lymphoma cell line. SCM-oPRL required concentrations greater than 1 X 10(5) that of native oPRL to stimulate 50% of the maximum cell growth. SCM-hGH retained a significant amount of its ability to stimulate the Nb 2 lymphoma cells.     

Neuropeptides of the pituitary adenylate cyclase-activating polypeptide/vasoactive intestinal polypeptide/growth hormone-releasing hormone/secretin family in testis

Mammalian testicular development and the maintenance of spermatogenesis are hormone-dependent processes that are controlled by the pituitary gonadotropins and testosterone. Recent studies have demonstrated the presence of many neuropeptides and their receptors in the testis, suggesting that these peptides operate as local regulators of testicular germ cell development and function. Among these testicular neuropeptides, the peptides that belong to the pituitary adenylate cyclase-activating polypeptide (PACAP) family, particularly growth hormone-releasing hormone and secretin, appear to show some unique common features in terms of intratesticular localization and the time of expression during the spermatogenic cycle. However, their precise physiologic roles and mechanisms of action remain unknown. This review analyzes the available information on the functional interactions among the testicular cells that appear to be mediated by locally produced neuropeptides, with a special emphasis on the peptides of the PACAP family.     

Binding sites of human growth hormone and ovine and bovine prolactins in the mammary gland and the liver of lactating dairy cow

Membrane preparations and Triton X-100 solubilized fractions from the mammary gland and liver of the lactating dairy cow were capable of specific binding of [125I]hGH and [125I]oPRL. The specific binding of the latter was significantly lower and could not be increased by higher receptor levels. Displacement studies of [125I]hGh by hGH, bPRL and oPRL revealed that the two latter hormones have a 20-40-fold lower affinity for the receptor than hGH, although strong indications exist that they all bind or the same sites. This feature is unique for cows and does not exist or is much less pronounced in rodents.     

重组人生长激素体外干预对人胃癌细胞膜GHR密度的影响

目的 观察重组人生长激素（rhGH）体外干预人胃癌细胞膜生长激素受体（GHR）密度变化及意义。方法采用免疫细胞化学法半定量检测人胃癌细胞株SGC-7901、BGC-823细胞膜表面GHR阳性表达状态;各胃癌细胞株根据不同处理方式分为四组,A、B、C组分别采取25、50、100ng／ml rhGH干预,D组未处理。采用放射性受体分析法定量检测四组GHR表达情况（饱和位点Bmax）。结果细胞株SGC-7901呈GHR高表达状态;A、B、C、D组胞膜表面GHR位点数分别为（3．733±0．101）、（4．035±0．419）、（3．865±0．265）、（2．968±0．425）10^4／cell,A、B、C较D组明显增加;细胞株BGC-823未表达GHR,各浓度rhGH干预后均未出现GHR表达情况。结论rhGH能明显增加GHR高表达细胞株SGC-7901胞膜表面GHR密度。     

Ancient origin of placental expression in the growth hormone genes of anthropoid primates

In anthropoid primates, growth hormone (GH) genes have undergone at least 2 independent locus expansions, one in platyrrhines (New World monkeys) and another in catarrhines (Old World monkeys and apes). In catarrhines, the GH cluster has a pituitary-expressed gene called GH1; the remaining GH genes include placental GHs and placental lactogens. Here, we provide cDNA sequence evidence that the platyrrhine GH cluster also includes at least 3 placenta expressed genes and phylogenetic evidence that placenta expressed anthropoid GH genes have undergone strong adaptive evolution, whereas pituitary-expressed GH genes have faced strict functional constraint. Our phylogenetic evidence also points to lineage-specific gene gain and loss in early placental mammalian evolution, with at least three copies of the GH gene present at the time of the last common ancestor (LCA) of primates, rodents, and laurasiatherians. Anthropoid primates and laurasiatherians share gene descendants of one of these three copies, whereas rodents and strepsirrhine primates each maintain a separate copy. Eight of the amino-acid replacements that occurred on the lineage leading to the LCA of extant anthropoids have been implicated in GH signaling at the maternal-fetal interface. Thus, placental expression of GH may have preceded the separate series of GH gene duplications that occurred in catarrhines and platyrrhines (i.e., the roles played by placenta-expressed GHs in human pregnancy may have a longer evolutionary history than previously appreciated).     

重组人生长激素对荷人胃癌细胞SGC-7901裸鼠移植瘤生长及VEGF表达的影响

目的:探讨重组人生长激素frhGH)对荷人胃癌细胞株SGC-7901裸鼠移植瘤生长及VEGF表达的影响.方法:免疫细胞化学染色法鉴定SGC-7901细胞株GHR表达状态,30只接种皮下移植瘤的裸鼠随机分为:对照组(生理盐水0.2 mL/d).低剂量rhGH组[0.5 U/(kg·d)],高剂量rhGH组[2.5 U/(kg·d)],连续给药14 d,观察并记录裸鼠体质量和肿瘤体积,酶联免疫吸附法测定血清VEGF含量,免疫组织化学法检测胃癌组织中VEGF蛋白表达,RT-PCR检测VEGFmRNA表达.结果:SGC-7901细胞株GHR呈强阳性表达.自rhGH给药第3天起,rhGH给药组与对照组肿瘤体积相差悬殊(P＜0.05),且高剂量rhGHVg低剂量rhGH促肿瘤生长效应更加明显(P＜0.05),3组间裸鼠体质量差别不明显(P＞0.05).裸鼠血清VEGF含量,与对照组和低剂量rhGH组相比,高剂量rhGH组血清中VEGF水平明显升高,差别具有统计学意义(252.94 ng/L±15.32ng/L VS 49.94 ng/L4±5.73 ng/L,167.60 ng/L±9.54 ng/L.均P＜0.05).肿瘤组织VEGF蛋白的表达,对照组VEGF表达呈中度阳性;低剂量rhGH组和高剂量rhGH组VEGF表达量高,呈强阳性.肿瘤组织VEGF mRNA表达水平,高剂量rhGH组VEGF相对表达量明显高于对照组和低剂量rhGH组,差别具有统计学意义(0.647±0.0447 vs 0.3234±.0258,0.412±0.035 1.均P＜0.05).结论:rhGH能促进GHR阳性表达的SGC-7901移植瘤生长,并促进VEGF表达.     

Human placental lactogen (hPL-A) activates signaling pathways linked to cell survival and improves insulin secretion in human pancreatic islets

The search for factors either promoting islets proliferation or survival during adult life is a major issue for both type 1 and 2 diabetes mellitus. Among factors with mitogenic activity on pancreatic β-cells, human placental lactogen (hPL) showed stronger activity when compared to the other lactogen hormones: growth hormone (GH) and prolactin (PRL). The aim of the present work is to elucidate the biological and molecular events of hPL isoform A (hPL-A) activity on human cultured islets. We used pure human pancreatic islets and insulinoma cell lines (βTC-1 and RIN, murine and rat respectively) stimulated with hPL-A recombinant protein and we compared hPL-A activity with that of hGH. We showed that hPL-A inhibits apoptosis, both in insulinoma and human islets, by the phosphorylation of AKT protein. Indeed, the antiapoptotic role of hPL-A was mediated by PI3K, p38 and it was independent by PKA, Erk1/2. Compared with hGH, hPL-A modulated at different intervals and/or intensity by the phosphorylation of JAKs/STATs and MAPKinases. Moreover, hPL-A induced PDX-1 intracellular expression, improving beta cell activity and ameliorating insulin secretion in response to high glucose stimulation. Our data support the idea that hPL-A is involved in the regulation of beta cells activity. Importantly, we found that hPL-A can preserve and improve the ability of purified human pancreatic islets cultured to secrete insulin in vitro.     

单纯促性腺激素释放激素类似物或联合重组人生长激素治疗青春期矮小患儿的疗效分析

Objective To assess the efficacy of gonadotropin-releasing hormone analogue(GnRHa)with or without recombinant human growth hormone(rhGH)treatment in Chinese short pubertal children with non-growth hormone deficiency.Methods Of 42 short pubertal children(14 males,28 females)without growth hormone deftcieney,the average age was(11.6±0.8)year.30 children were treated with slow release GnRHa with initial dose (100μg·kg-1·d-1,28d)and maintenance dose(60-80μg·kg-1·d-1,28d)labd rgGH with initial dose(0.15IU·kg-1·d-1)and maintenance dose(0.10-0.15IU·kg-1·d-1)for at least 1year.16 of them were still ongoing till the end of the second year.12 children were treated with GnRHa alone by initial dose(100μg·kg-1·d-1,28d)and maintenance dose (60-80μg·kg-1·d-1,28d),and 7 of them remained on it for 2 years.Dynamic changes including annual growth velocity(GV),bone age(BA)/chronologic age(CA)ratio,Tanner stage,height SDS for CA (HtSDSCA),height SDS for BA(HtSDSBA),and predicted adult height (PAHSDS)were observed.Results By the end of the first year tretment with combination therapy,the following parameters:GV,HtSDSCA,HtSDSBA,and PAHSDS all increased significantly(all P<0.05).Treatment with GnRHa alone did not yield significant changes in GV,HtSDSCA,HtSDSBA,and PAHSDS(all P>0.05).Changes in GV,HtSDSBA,and PAHSDS between these two groups were statistically significant(all P<0.05).By the end of the second year treatment,in the combination group,GV slowed from 6.7 to 5.5 cm/year(P<0.05).HtSDSCA,HtSDSBA,PAHSDS increased(all P<0.05).In the group with GnRHa treatment alone,GV slowed from 4.0 to 3.6 cm/year(P>0.05).HtSDSCA,HtSDSBA,PAHSDS increased(all P>0.05).Changes in GV,HtSDSCA,HtSDSBA,and PAHSDS between these 2 groups were statistically significant respectively(all P<0.05).Conclusion This combined treatment regimen significantly impreved the growth by increasing growth rate and delaying bone matumtion in pubertal chidren without growth hormone deficiency.Further study is needed to verify beneficial effects on the final height gain.     

单纯促性腺激素释放激素类似物或联合重组人生长激素治疗青春期矮小患儿的疗效分析

Objective To assess the efficacy of gonadotropin-releasing hormone analogue(GnRHa)with or without recombinant human growth hormone(rhGH)treatment in Chinese short pubertal children with non-growth hormone deficiency.Methods Of 42 short pubertal children(14 males,28 females)without growth hormone deftcieney,the average age was(11.6±0.8)year.30 children were treated with slow release GnRHa with initial dose (100μg·kg-1·d-1,28d)and maintenance dose(60-80μg·kg-1·d-1,28d)labd rgGH with initial dose(0.15IU·kg-1·d-1)and maintenance dose(0.10-0.15IU·kg-1·d-1)for at least 1year.16 of them were still ongoing till the end of the second year.12 children were treated with GnRHa alone by initial dose(100μg·kg-1·d-1,28d)and maintenance dose (60-80μg·kg-1·d-1,28d),and 7 of them remained on it for 2 years.Dynamic changes including annual growth velocity(GV),bone age(BA)/chronologic age(CA)ratio,Tanner stage,height SDS for CA (HtSDSCA),height SDS for BA(HtSDSBA),and predicted adult height (PAHSDS)were observed.Results By the end of the first year tretment with combination therapy,the following parameters:GV,HtSDSCA,HtSDSBA,and PAHSDS all increased significantly(all P<0.05).Treatment with GnRHa alone did not yield significant changes in GV,HtSDSCA,HtSDSBA,and PAHSDS(all P>0.05).Changes in GV,HtSDSBA,and PAHSDS between these two groups were statistically significant(all P<0.05).By the end of the second year treatment,in the combination group,GV slowed from 6.7 to 5.5 cm/year(P<0.05).HtSDSCA,HtSDSBA,PAHSDS increased(all P<0.05).In the group with GnRHa treatment alone,GV slowed from 4.0 to 3.6 cm/year(P>0.05).HtSDSCA,HtSDSBA,PAHSDS increased(all P>0.05).Changes in GV,HtSDSCA,HtSDSBA,and PAHSDS between these 2 groups were statistically significant respectively(all P<0.05).Conclusion This combined treatment regimen significantly impreved the growth by increasing growth rate and delaying bone matumtion in pubertal chidren without growth hormone deficiency.Further study is needed to verify beneficial effects on the final height gain.     

Selective modification at the N-terminal region of human growth hormone that shows antagonistic activity

A new analogue of recombinant human growth hormone (hGH), hGH des(1–6,14) was expressed in Escherichia coli, refolded and purified to homogeneity. The mutation decreased the hormone's ability to bind lactogenic and somatogenic receptors through its site 1, and almost completely abolished its ability to bind these receptors through site 2, as evidenced by both binding and gel-filtration experiments. More specifically, the binding to prolactin receptors (PRLRs) from various species or their soluble recombinant extracellular domains (ECDs) was decreased 1.5–4-fold, whereas the binding to hGH receptor (hGHR) was decreased 10–85-fold. These changes caused an almost total loss of hormone agonistic activity in several in vitro bioassays and subsequently, the hGH des(1–6,14) analogue acquired antagonistic properties. This antagonistic activity was dependent upon modification of site 1. In those cases in which the binding was reduced only slightly, e.g. binding to rabbit PRLRs, hGH des(1–6,14) acted as a strong antagonist, whereas in others in which the binding of site 1 was reduced to a higher degree, such as other PRLRs and, in particular, hGHR, the antagonistic activity was correspondingly weaker. Circular dichroism spectra of the analogue suggested that these changes do not result from a decrease in overall -helix content, but rather from minor local structural modifications at the N-terminus.     

Interactions of growth hormone secretagogues and growth hormone-releasing hormone/somatostatin

The class of novel synthetic compounds termed growth hormone secretagogues (GHSs) act in the hypothalamus through, as yet, unknown pathways. We performed physiologic and histochemical studies to further understand how the GHS system interacts with the well-established somatostatin (SRIF)/growth hormone-releasing hormone (GHRH) neuroendocrine system for regulating pulsatile GH secretion. Comparison of the GH-releasing activities of the hexapeptide growth hormone-releasing peptide-6 (GHRP-6) and GHRH administered intravenously to conscious adult male rats showed that the pattern of GH responsiveness to GHRP-6 was markedly time-dependent, similar to that observed with GHRH. Immunoneutralization of endogenous SRIF reversed the blunted GH response to GHRP-6 at trough times, suggesting that GHRP-6 neither disrupts nor inhibits the cyclical release of endogenous hypothalamic SRIF. By striking contrast, passive immunization with anti-GHRH serum virtually obliterated the GH responses to GHRP-6, irrespective of the time of administration. These findings suggest that the GHSs do not act by altering SRIF release but, rather, stimulate GH release via GHRH-dependent pathways. Our dual chromogenic and autoradiographic in situ hybridization experiments revealed that a subpopulation of GHRH mRNA-containing neurons in the arcuate (Arc) nucleus and ventromedial nucleus (VMN) of the hypothalamus expressed the GHS receptor (GHS-R) gene. These results provide strong anatomic evidence that GHSs may directly stimulate GHRH release into hypophyseal portal blood, and thereby influence GH secretion, through interaction with the GHS-R on GHRH- containing neurons. Altogether, these findings support the notion that an additional neuroendocrine pathway may exist to regulate pulsatile GH secretion, possibly through the influence of the newly discovered GHS natural peptide, ghrelin.     

Development of heterologous down-regulation of lactogen receptors in the rat testis

Gonadotropin-induced loss (down-regulation) of testicular lactogen receptors was studied in 5–60-day-old rats. An i.m. injection of 600 IU/kg of hCG elicited in 5-day-old animals a 38–56% increase in testicular lactogen binding, measurable between 6 and 72 h after the hormone injection. In contrast, at the age of 60 days the same hCG dose decreased lactogen receptors by 75% at 24 h, which loss recovered in 2–3 days. When the amount of lactogen receptors was measured 24 h after the hCG injection (600 lU/kg) at different ages, the binding increased on average by 50% between ages 5 and 20 days, no effect on binding was seen at day 30, and a loss of binding by 50% was evident in animals of 40 days of age and older. The present results indicate that the plasma-membrane events elicited by gonadotropin binding to neonatal Leydig cells are clearly different from those occurring in the adult, and that down-regulation and functional coupling of LH and lactogen receptors are accompaniments of functional differentiation of the Leydig cell during pubertal maturation.     

重组人生长激素治疗重症乙型肝炎的临床研究

[目的]研究重组人生长激素(rhGH)对重症乙型肝炎(重肝)的治疗作用.[方法]选择42例住院的重肝患者,随机分成rhGH组20例和对照组22例,rhGH组给予rhGH 10 U隔日1次或3 U每日1次,肌肉注射,连续2周,观察治疗前和治疗后1、2及4周肝功能、总胆红素(TB)和血清白蛋白(Alb)水平.[结果]rhGH组治疗后肝功能、TB和Alb显著改善,与对照组和治疗前相比差异有统计学意义(P＜0.01～0.05).[结论]rhGH能有效的改善重肝的肝功能,降低胆红素和纠正低蛋白血症.     

Efficacy and safety of individualized growth hormone treatment in adult Japanese patients with growth hormone deficiency

OBJECTIVE: The aim of the study was to evaluate the efficacy and safety of growth hormone (GH) treatment in Japanese adult patients with GH-deficiency. In the extension of the efficacy study, the effect of individualized-dosing (ID), based on insulin-like growth factor-I (IGF-I) levels, and fixed-dose (FD) GH regimens on body composition, were compared in Japanese GH-deficient adults. DESIGN: Randomized, double-blind (DB), placebo-controlled, 24-week treatment period followed by 48-week, open-label study in 43 endocrinology clinics in Japan. Patients received DB treatment with GH (0.012 mg/kg/day; n=57) or placebo (n=60) followed by open-label GH in an ID (n=75) or FD (0.012 mg/kg/day; n=38) regimen. SUBJECTS: Adult Japanese GH-deficient patients (peak GH<3 ng/mL). MEASUREMENTS: Trunk and total body fat (BF), lean body mass (LBM), and adverse events were determined. RESULTS: Percentage trunk fat was reduced significantly more in GH- than in placebo-treated patients at 24 weeks (-16.2 vs. 1.7%, p<0.0001). Open-label treatment with an ID or FD GH regimen provided similar reductions in percentage trunk fat (-8.12 vs. -9.35%), and total BF (-0.92 vs. -0.70 kg) and a comparable increase in LBM (1.032 vs. 0.97 kg). Mean+/-SD GH doses (mg/kg/day) at 48 weeks were significantly lower with the ID GH regimen (ID, 0.0082+/-0.0050; FD, 0.0095+/-0.0033; p<0.05). The safety profile was comparable between ID and FD groups. CONCLUSIONS: Treatment with GH was associated with a significant reduction in trunk fat and improvement in serum lipid profile in Japanese adult GH-deficient patients. The improvement in body composition and tolerability were comparable between ID and FD GH regimens despite a significantly lower daily GH dose with the ID regimen.     

重组人生长激素治疗不同生长激素分泌状态青春前期矮小患儿追赶性生长模式分析

目的 比较不同生长激素(GH)分泌状态矮小患儿重组人生长激素(rhGH)治疗后的初始追赶性生长模式,初步探讨其机制.方法 回顾性分析62例青春前期不同GH分泌状态矮小患儿对rhGH治疗1年半的追赶性生长模式并定期监测体格指标、促生长素轴的血清指标和骨龄.结果 各组在初始追赶性生长的幅度相似,特发性矮小(ISS)组比完全性生长激素缺乏症(GHD)组更早出现生长减速,并与生长激素结合蛋白(GHBP)水平降低和胰岛素样生长因子结合蛋白3的标准差分数(SDS)增值较小显著相关.GH激发峰值(Ghmax)>7μg/L的部分性GHD组与ISS组有类同的生长追赶的模式.结论 GH受体的降调节和受体后效应的降低可能是ISS组较早出现生长减速的机制.以Ghmaxμg/L作为GHD诊断的界值并相应选择rhGH治疗剂量有更充分的依据和临床意义.