OBJECTIVE: To study the value of serum insulin-like growth factor binding protein-3 (IGFBP-3) levels in differential diagnosis of growth hormone deficiency (GHD). METHODS: To measure serum IGFBP-3 levels by RIA in nor...OBJECTIVE: To study the value of serum insulin-like growth factor binding protein-3 (IGFBP-3) levels in differential diagnosis of growth hormone deficiency (GHD). METHODS: To measure serum IGFBP-3 levels by RIA in normal children and adolescents, GHD children and short-stature children without GHD. RESULTS: Serum level of IGFBP-3 in 129 children with untreated GHD and with no pubertal development was 1.6 +/- 0.9 mg/L, which was less than that in normal group of the same age, but overlapped with the normal children in Tanner stage I. After six-month treatment with recombinant human growth hormone (rhGH), serum level of IGFBP-3 in 59 GHD significantly increased from 1.3 +/- 0.7 mg/L to 2.7 +/- 0.9 mg/L, accompanied by an increase of body heights, growth velocities and serum level of IGF-1. Serum level of IGFBP-3 in 55 short-stature children without GHD was 3.3 +/- 2.2 mg/L, which was not significantly different from that in normal group. CONCLUSION: Serum IGFBP-3 level can reflect the status of GH secretion in children with GHD and is a useful marker for differential diagnosis of GHD.展开更多
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 es...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.展开更多
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&#...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.展开更多
Objective To evaluate physicians' attitude and knowledge about the management of adult growth hormone deficiency(AGHD) at Peking Union Medical College Hospital and impact factors associated with better decision-ma...Objective To evaluate physicians' attitude and knowledge about the management of adult growth hormone deficiency(AGHD) at Peking Union Medical College Hospital and impact factors associated with better decision-making.Methods A 21-question anonymous survey was distributed and collected at Peking Union Medical College Hospital,a major teaching hospital in Chinese Academy of Medical Sciences.Data of physicians' educational background,clinical training,patient workload per year and continuing medical education in AGHD were collected.Factors associated with appropriate answers were further analyzed by multivariate regression models.Results One hundred and eighteen internal medicine residents,endocrine fellows,attending physicians and visiting physicians responded to the survey.Among them,44.9% thought that AGHD patients should accept recombinant human growth hormone replacement therapy.Moreover,56.8% selected insulin tolerance test and growth hormone-releasing hormone-arginine test for the diagnosis of AGHD.Logistic regression analysis of physician demographic data,educational background,and work experience found no consistent independent factors associated with better decision-making,other than continued medical education,that were associated with treatment choice.Conclusions The physicians' reported management of AGHD in this major academic healthcare center in Beijing was inconsistent with current evidence.High quality continued medical education is required to improve Chinese physician management of AGHD.展开更多
To evaluate the therapeutic effect of China-made recombinant human growth hormone (r-hGH) in children with growth hormone deficiency (GHD) and to investigate the utilities of various biochemical parameters in GHD diag...To evaluate the therapeutic effect of China-made recombinant human growth hormone (r-hGH) in children with growth hormone deficiency (GHD) and to investigate the utilities of various biochemical parameters in GHD diagnosis and treatment. Methods Our study comprises of 30 normal children and 71 GHD children treated with China-made r-hGH substitution therapy 0.1 IU·kg-1·d-1 for 6 months. Serum insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein 3 (IGFBP-3), bone turnover markers (Ost, ICTP), and anti-growth hormone antibody (GHAb) were detected before and after r-hGH treatment. Results After the first 3 and 6 months of treatment, growth velocities of GHD children were significantly increased (13.1 ± 3.7 and 12.6 ± 3.6 cm/year) compared with pretreatment values (2.9 ± 0.8 cm/year, P < 0.01). GHD Children had obviously reduced serum levels of IGF-1, IGFBP-3, and bone turnover markers (Ost, ICTP) compared with normal controls (P < 0.01), and these biochemical parameters improved significantly after treatment (P < 0.01). Growth hormone antibodies were positive in 17 of 45 cases after treatment by binding capacity detection. The binding percentage of growth hormone an-tibody which was increased more than 30% after the treatment showed a negative correlation with growth velocity (P < 0.01). Conclusions (1) The growth stimulating effect and safety were confirmed in using China-made r-hGH in the treatment of GHD children for 6 months. (2) The measurements of serum IGF-1 and IGFBP-3 may serve as useful parameters in the diagnosis of GHD. (3) Serum Ost and ICTP are useful laboratory criteria for evaluating the effect of r-hGH therapy in the early stage. (4) It is necessary to monitor serum levels of GHAb during r-hGH therapy.展开更多
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).T...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.展开更多
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 ...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.展开更多
Acromegaly is an insidious endocrine disease character- ized by chronic elevation of growth hormone （GH） and insulin-like growth factor-1 （IGF-1）.Ell Persistent excess se- cretion of GH and IGF-1 damages both card...Acromegaly is an insidious endocrine disease character- ized by chronic elevation of growth hormone （GH） and insulin-like growth factor-1 （IGF-1）.Ell Persistent excess se- cretion of GH and IGF-1 damages both cardiac structure and function, leading to acromegalic cardiomyopathy, which is one of the most common causes of increased mortality in acromegaly and can result in an average of 10-year reduction in life expectancy.I2＇31 In patients with acromegaly, approximately 3% have been reported having a unique cardiomyopathy characterized by biventricular hypertrophy, myocardial necrosis, lymphocytic infiltration, interstitialfibrosis.展开更多
In order to describe the magnetic resonance imaging (MRI) findings in hypothalamic-pituitary area and its clinical relevance in patients with idiopathic growth hormone deficiency (IGHD), the MR imagings of 26 patients...In order to describe the magnetic resonance imaging (MRI) findings in hypothalamic-pituitary area and its clinical relevance in patients with idiopathic growth hormone deficiency (IGHD), the MR imagings of 26 patients with IGHD were analyzed. On MRI, 24 out of 26 cases (92. 3%) showed apparent pituitary upper margin depression; 8 out of 26 cases (30. 8%) showed definite pituitary stalk transection; 22 out of 26 cases (84. 6%) showed absence of the normal posterior pituitary bright spot. The bright lipidlike signal on T1W1 images at the median eminence distal to the breaking point (so-called ectopic posterior lobe) was found in 4 out of 26 cases (15. 4%). According to the MRI findings of the pituitary stalks, the 26 cases were divided into three groups; group A of 8 cases (31%) characterized by the definite transaction of stalk; group B of 13 cases (50%) defined by the possible stalk transection; and group C of 5 cases (19%) with no definite stalk transection.MRI findings were consistent with the clinical and endocrine tests. The stalk transection was statistically significantly difference in insulin test, L-dopa/p test, and height standard deviation score (P< 0.05). The MRI of hypothalamic-pituitary area may differentiate partial IGHD form stalk-transected, doubtful transection and without transection.展开更多
Hexarelin, a synthetic growth hormone-releasing peptide, can bind to and activate the growth hormone secretagogue receptor （GHSR） in the brain similar to its natural analog ghrelin. However, the peripheral distribut...Hexarelin, a synthetic growth hormone-releasing peptide, can bind to and activate the growth hormone secretagogue receptor （GHSR） in the brain similar to its natural analog ghrelin. However, the peripheral distribution of GHSR in the heart and blood vessels suggests that hexarelin might have direct cardiovascular actions beyond growth hormone release and neuroendocrine effects. Furthermore, the non-GHSR CD36 had been demonstrated to be a specific cardiac receptor for hexarelin and to mediate its cardioprotective effects. When compared with ghrelin, hexarelin is chemically more stable and functionally more potent. Therefore, it may be a promising therapeutic agent for some car-diovascular conditions. In this concise review, we discuss the current evidence for the cardiovascular action of hexarelin.展开更多
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 wa...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.展开更多
文摘OBJECTIVE: To study the value of serum insulin-like growth factor binding protein-3 (IGFBP-3) levels in differential diagnosis of growth hormone deficiency (GHD). METHODS: To measure serum IGFBP-3 levels by RIA in normal children and adolescents, GHD children and short-stature children without GHD. RESULTS: Serum level of IGFBP-3 in 129 children with untreated GHD and with no pubertal development was 1.6 +/- 0.9 mg/L, which was less than that in normal group of the same age, but overlapped with the normal children in Tanner stage I. After six-month treatment with recombinant human growth hormone (rhGH), serum level of IGFBP-3 in 59 GHD significantly increased from 1.3 +/- 0.7 mg/L to 2.7 +/- 0.9 mg/L, accompanied by an increase of body heights, growth velocities and serum level of IGF-1. Serum level of IGFBP-3 in 55 short-stature children without GHD was 3.3 +/- 2.2 mg/L, which was not significantly different from that in normal group. CONCLUSION: Serum IGFBP-3 level can reflect the status of GH secretion in children with GHD and is a useful marker for differential diagnosis of GHD.
文摘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.
文摘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.
基金Supported by National Natural Science Foundation of China(81400774)PUMC Youth Fund(33320140164 and 3332016128)
文摘Objective To evaluate physicians' attitude and knowledge about the management of adult growth hormone deficiency(AGHD) at Peking Union Medical College Hospital and impact factors associated with better decision-making.Methods A 21-question anonymous survey was distributed and collected at Peking Union Medical College Hospital,a major teaching hospital in Chinese Academy of Medical Sciences.Data of physicians' educational background,clinical training,patient workload per year and continuing medical education in AGHD were collected.Factors associated with appropriate answers were further analyzed by multivariate regression models.Results One hundred and eighteen internal medicine residents,endocrine fellows,attending physicians and visiting physicians responded to the survey.Among them,44.9% thought that AGHD patients should accept recombinant human growth hormone replacement therapy.Moreover,56.8% selected insulin tolerance test and growth hormone-releasing hormone-arginine test for the diagnosis of AGHD.Logistic regression analysis of physician demographic data,educational background,and work experience found no consistent independent factors associated with better decision-making,other than continued medical education,that were associated with treatment choice.Conclusions The physicians' reported management of AGHD in this major academic healthcare center in Beijing was inconsistent with current evidence.High quality continued medical education is required to improve Chinese physician management of AGHD.
文摘To evaluate the therapeutic effect of China-made recombinant human growth hormone (r-hGH) in children with growth hormone deficiency (GHD) and to investigate the utilities of various biochemical parameters in GHD diagnosis and treatment. Methods Our study comprises of 30 normal children and 71 GHD children treated with China-made r-hGH substitution therapy 0.1 IU·kg-1·d-1 for 6 months. Serum insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein 3 (IGFBP-3), bone turnover markers (Ost, ICTP), and anti-growth hormone antibody (GHAb) were detected before and after r-hGH treatment. Results After the first 3 and 6 months of treatment, growth velocities of GHD children were significantly increased (13.1 ± 3.7 and 12.6 ± 3.6 cm/year) compared with pretreatment values (2.9 ± 0.8 cm/year, P < 0.01). GHD Children had obviously reduced serum levels of IGF-1, IGFBP-3, and bone turnover markers (Ost, ICTP) compared with normal controls (P < 0.01), and these biochemical parameters improved significantly after treatment (P < 0.01). Growth hormone antibodies were positive in 17 of 45 cases after treatment by binding capacity detection. The binding percentage of growth hormone an-tibody which was increased more than 30% after the treatment showed a negative correlation with growth velocity (P < 0.01). Conclusions (1) The growth stimulating effect and safety were confirmed in using China-made r-hGH in the treatment of GHD children for 6 months. (2) The measurements of serum IGF-1 and IGFBP-3 may serve as useful parameters in the diagnosis of GHD. (3) Serum Ost and ICTP are useful laboratory criteria for evaluating the effect of r-hGH therapy in the early stage. (4) It is necessary to monitor serum levels of GHAb during r-hGH therapy.
基金supported by National Natural Special Scientific and Techndogical Resources Sharing Platform (No.2005DKA21101)the 11th Five-year Plan of National Science and Technology Support(No.2006BAD73B08)the 15th Key Project"Chinese Experimental Miniature Pig Resources Development and Research Applications"Ministry of Science and Technology(No.2004BA717B- 01)
文摘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.
文摘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.
文摘Acromegaly is an insidious endocrine disease character- ized by chronic elevation of growth hormone （GH） and insulin-like growth factor-1 （IGF-1）.Ell Persistent excess se- cretion of GH and IGF-1 damages both cardiac structure and function, leading to acromegalic cardiomyopathy, which is one of the most common causes of increased mortality in acromegaly and can result in an average of 10-year reduction in life expectancy.I2＇31 In patients with acromegaly, approximately 3% have been reported having a unique cardiomyopathy characterized by biventricular hypertrophy, myocardial necrosis, lymphocytic infiltration, interstitialfibrosis.
文摘In order to describe the magnetic resonance imaging (MRI) findings in hypothalamic-pituitary area and its clinical relevance in patients with idiopathic growth hormone deficiency (IGHD), the MR imagings of 26 patients with IGHD were analyzed. On MRI, 24 out of 26 cases (92. 3%) showed apparent pituitary upper margin depression; 8 out of 26 cases (30. 8%) showed definite pituitary stalk transection; 22 out of 26 cases (84. 6%) showed absence of the normal posterior pituitary bright spot. The bright lipidlike signal on T1W1 images at the median eminence distal to the breaking point (so-called ectopic posterior lobe) was found in 4 out of 26 cases (15. 4%). According to the MRI findings of the pituitary stalks, the 26 cases were divided into three groups; group A of 8 cases (31%) characterized by the definite transaction of stalk; group B of 13 cases (50%) defined by the possible stalk transection; and group C of 5 cases (19%) with no definite stalk transection.MRI findings were consistent with the clinical and endocrine tests. The stalk transection was statistically significantly difference in insulin test, L-dopa/p test, and height standard deviation score (P< 0.05). The MRI of hypothalamic-pituitary area may differentiate partial IGHD form stalk-transected, doubtful transection and without transection.
文摘Hexarelin, a synthetic growth hormone-releasing peptide, can bind to and activate the growth hormone secretagogue receptor （GHSR） in the brain similar to its natural analog ghrelin. However, the peripheral distribution of GHSR in the heart and blood vessels suggests that hexarelin might have direct cardiovascular actions beyond growth hormone release and neuroendocrine effects. Furthermore, the non-GHSR CD36 had been demonstrated to be a specific cardiac receptor for hexarelin and to mediate its cardioprotective effects. When compared with ghrelin, hexarelin is chemically more stable and functionally more potent. Therefore, it may be a promising therapeutic agent for some car-diovascular conditions. In this concise review, we discuss the current evidence for the cardiovascular action of hexarelin.
文摘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.
