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...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.展开更多
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 m...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.展开更多
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 g...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.展开更多
N-hydroxysuccinimide (HOSU) active esters have gained wide application in peptide synthesis, especially in the synthesis of longer peptides by segment conden sation, for they can avoid racemization during coupling pro...N-hydroxysuccinimide (HOSU) active esters have gained wide application in peptide synthesis, especially in the synthesis of longer peptides by segment conden sation, for they can avoid racemization during coupling processes. However, the HOSU active ester method is prone to side reactions, forming undesirable by-products such as succinimide-oxycarbonyl-alanine N-hydroxysuccinimide ester (Ⅰ) in activating steps and compound (Ⅱ) in the coupling steps sterically hindered by amino acids (proline, valine, isoleucine, etc.).展开更多
基金National Nature Science Foundation of China, No. 30400429
文摘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.
基金sponsored by the Natural Science Foundation of Hebei Province,H2012406018,H2013406096a grant from Hebei Province Department of Education,No.2006301
文摘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.
文摘目的探讨不同病因矮小症患儿血清生长激素释放肽(Ghrelin)、胰岛素样生长因子-1(insulinlike growth factor-1,IGF-1)水平变化及其临床意义。方法选取2016年1月至2022年1月南通大学附属医院如皋分院收治的212例矮小症患儿,根据不同病因分为生长激素缺乏症组(n=60)、特发性矮小症组(n=46)、Turner综合征组(n=38)、先天性甲状腺功能减退症组(n=32)和宫内发育迟缓组(n=36),另选取同期于本院行体检证实身高同性别、同年龄标准范围内的106例健康儿童作为对照组。比较不同病因矮小症患儿与对照组的人口学特征和骨龄年龄差(bone age difference,BAD)、身高标准差分值(heightstandard deviation score,Ht SDS)、年生长速率(growth velocity,GV)和生长激素(growth hormone,GH)峰值等生长发育指标及青春前期和青春期的血清Ghrelin、IGF-1水平。采用受试者操作特征(receiveroperating characteristic,ROC)曲线分析血清Ghrelin、IGF-1水平对特发性矮小症的鉴别诊断价值。统计学方法采用单因素方差分析、LSD-t检验及χ^(2)检验。结果特发性矮小症组青春期患儿比例为65.2%,明显高于其他4组(P值均<0.05),其中青春期患儿比例从高至低依次为宫内发育迟缓组(41.7%)、先天性甲状腺功能减退症组(40.6%)、生长激素缺乏症组(35.0%)和Turner综合征组(31.6%);特发性矮小症组BAD为(1.4±0.3)岁,明显高于其他4组(P值均<0.05),其中BAD值从高至低依次为生长激素缺乏症组[(1.2±0.2)岁]、先天性甲状腺功能减退症组[(1.1±0.2)岁]、Turner综合征组[(0.7±0.1)岁]和宫内发育迟缓组[(0.3±0.1)岁]。特发性矮小症组GV值为[(3.7±0.8)cm/年],明显高于其他4组(P值均<0.05),其中GV值从高至低依次为生长激素缺乏症组[(2.2±0.7)cm/年]、宫内发育迟缓组[(2.1±0.6)cm/年]、先天性甲状腺功能减退症组[(1.7±0.5)cm/年]和Turner综合征组[(1.2±0.4)cm/年]。生长激素缺乏症组GH峰值为[(6.4±0.3)μg/L],明显低于其他4组(P值均<0.05),其中GH峰值从低至高依次为宫内发育迟缓组[(13.4±3.2)μg/L]、Turner综合征组[(14.2±2.1)μg/L]、特发性矮小症组[(14.7±2.5)μg/L]和先天性甲状腺功能减退症组[(15.6±2.9)μg/L]。Turner综合征组Ghrelin水平显著高于生长激素缺乏症组、特发性矮小症组、先天性甲状腺功能减退症组和宫内发育迟缓组(P值均<0.05);先天性甲状腺功能减退症组IGF-1水平显著低于生长激素缺乏症组、特发性矮小症组、Turner综合征组和宫内发育迟缓组(P值均<0.05)。特发性矮小症组青春前期的血清Ghrelin、IGF-1水平均明显低于青春期(P值均<0.05)。ROC曲线分析结果显示,血清Ghrelin、IGF-1鉴别诊断特发性矮小症的曲线下面积(area under the curve,AUC)分别为0.776、0.733,联合检测鉴别诊断特发性矮小症的AUC为0.839,灵敏度为90.0%,特异性为65.6%(P<0.001)。结论不同病因矮小症患儿血清Ghrelin、IGF-1水平均存在异常表达,特发性矮小症患儿在青春前期和青春期的血清Ghrelin、IGF-1水平差异明显,血清Ghrelin、IGF-1联合检测对特发性矮小症的鉴别诊断具有较好的诊断效能。
基金This study was supported by a grant from National Natural Science Foundation of China （No. 30400429）.
文摘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.
文摘N-hydroxysuccinimide (HOSU) active esters have gained wide application in peptide synthesis, especially in the synthesis of longer peptides by segment conden sation, for they can avoid racemization during coupling processes. However, the HOSU active ester method is prone to side reactions, forming undesirable by-products such as succinimide-oxycarbonyl-alanine N-hydroxysuccinimide ester (Ⅰ) in activating steps and compound (Ⅱ) in the coupling steps sterically hindered by amino acids (proline, valine, isoleucine, etc.).
