Objective To evaluate the effects of acute glucose level changes on expression of prepro-orexin, orexin 1 receptor (OX1R) and orexin 2 receptor (OX2R) mRNA in rat hypothalamus tissue and pancreatic islets cells. Metho...Objective To evaluate the effects of acute glucose level changes on expression of prepro-orexin, orexin 1 receptor (OX1R) and orexin 2 receptor (OX2R) mRNA in rat hypothalamus tissue and pancreatic islets cells. Methods Thirty adult male Wistar rats were randomly divided into three equal groups (n = 10). The acute hypoglycemia rat model was induced by a single subcutaneous injection of insulin. Twenty acute hypoglycemia rats were divided into group B and group C. Group B was allowed to eat freely, while group C was food-deprived. Control rats were injected the same volume of saline. The effect of glucose levels (2.8 mmol/L and 8.3 mmol/L) on pancreatic islet cell orexin system was detected in pancreas islet cell cultured in vitro. The expression of prepro-orexin and OXR mRNA was examined in rat hypothalamus tissue and pancreatic islets cell cultured in vitro using reverse transcription-polymerase chain reaction (RT-PCR). Results Expression of orexin mRNA increased about 150% for the food-deprived hypoglycemia rats in comparison with control group (P < 0.01), whereas expression of OX1R mRNA decreased up to 30% (P < 0.01). However, expression of OX2R mRNA was unchanged in comparison with control group. In vitro, after incubation with 2.8 mmol/L glucose for 6 hours, the expression of prepro-orexin mRNA increased 2 times in rat pancreas islet cells in comparison with 8.3 mmol/L glucose group (P < 0.01). But the expression of OX1R mRNA was not sensitive to acute glucose fluctuation.Conclusions Orexin in rat hypothalamus is stimulated by decline in blood glucose and inhibited by signals related to feeding. Moreover, glucose plays a role in modulating the gene expression of prepro-orexin in rat pancreatic islet cells.展开更多
The purpose of this study is to gain understanding of the relationshi p between ejaculation and serum testosterone level in men. The serum testosteron e concentrations of 28 volunteers were investigated daily during a...The purpose of this study is to gain understanding of the relationshi p between ejaculation and serum testosterone level in men. The serum testosteron e concentrations of 28 volunteers were investigated daily during abstinence peri ods after ejaculation for two phases. The authors found that the fluctuations o f testosterone levels from the 2nd to 5th day of abstinence were minimal. On the 7th day of abstinence, however, a clear peak of serum testosterone appeared, re aching 145.7% of the baseline (P<0.01). No regular fluctuation was observed foll owing continuous abstinence after the peak. Ejaculation is the precondition and beginning of the special periodic serum testosterone level variations, which wou ld not occur without ejaculation. The results showed that ejaculation-caused va r iations were characterized by a peak on the 7th day of abstinence; and that the effective time of an ejaculation is 7 days minimum. These data are the first to document the phenomenon of the periodic change in serum testosterone level; the correlation between ejaculation and periodic change in the serum testosterone le vel, and the pattern and characteristics of the periodic change.展开更多
基金Supported by Important FinancialIssueof Shi-Wu Programming Key Problem in Liaoning Provinceand Financial Issue for Scientific Research in the Department of Education.
文摘Objective To evaluate the effects of acute glucose level changes on expression of prepro-orexin, orexin 1 receptor (OX1R) and orexin 2 receptor (OX2R) mRNA in rat hypothalamus tissue and pancreatic islets cells. Methods Thirty adult male Wistar rats were randomly divided into three equal groups (n = 10). The acute hypoglycemia rat model was induced by a single subcutaneous injection of insulin. Twenty acute hypoglycemia rats were divided into group B and group C. Group B was allowed to eat freely, while group C was food-deprived. Control rats were injected the same volume of saline. The effect of glucose levels (2.8 mmol/L and 8.3 mmol/L) on pancreatic islet cell orexin system was detected in pancreas islet cell cultured in vitro. The expression of prepro-orexin and OXR mRNA was examined in rat hypothalamus tissue and pancreatic islets cell cultured in vitro using reverse transcription-polymerase chain reaction (RT-PCR). Results Expression of orexin mRNA increased about 150% for the food-deprived hypoglycemia rats in comparison with control group (P < 0.01), whereas expression of OX1R mRNA decreased up to 30% (P < 0.01). However, expression of OX2R mRNA was unchanged in comparison with control group. In vitro, after incubation with 2.8 mmol/L glucose for 6 hours, the expression of prepro-orexin mRNA increased 2 times in rat pancreas islet cells in comparison with 8.3 mmol/L glucose group (P < 0.01). But the expression of OX1R mRNA was not sensitive to acute glucose fluctuation.Conclusions Orexin in rat hypothalamus is stimulated by decline in blood glucose and inhibited by signals related to feeding. Moreover, glucose plays a role in modulating the gene expression of prepro-orexin in rat pancreatic islet cells.
文摘The purpose of this study is to gain understanding of the relationshi p between ejaculation and serum testosterone level in men. The serum testosteron e concentrations of 28 volunteers were investigated daily during abstinence peri ods after ejaculation for two phases. The authors found that the fluctuations o f testosterone levels from the 2nd to 5th day of abstinence were minimal. On the 7th day of abstinence, however, a clear peak of serum testosterone appeared, re aching 145.7% of the baseline (P<0.01). No regular fluctuation was observed foll owing continuous abstinence after the peak. Ejaculation is the precondition and beginning of the special periodic serum testosterone level variations, which wou ld not occur without ejaculation. The results showed that ejaculation-caused va r iations were characterized by a peak on the 7th day of abstinence; and that the effective time of an ejaculation is 7 days minimum. These data are the first to document the phenomenon of the periodic change in serum testosterone level; the correlation between ejaculation and periodic change in the serum testosterone le vel, and the pattern and characteristics of the periodic change.
