Aim： To study the effect and mechanism of gonadotrophin-releasing hormone （GnRH） on murine Leydig cell steroidogenesis. Methods： Purified murine Leydig cells were treated with GnRH-Ⅰ and -Ⅱ agonists, and testost...Aim： To study the effect and mechanism of gonadotrophin-releasing hormone （GnRH） on murine Leydig cell steroidogenesis. Methods： Purified murine Leydig cells were treated with GnRH-Ⅰ and -Ⅱ agonists, and testosterone production and steroidogenic enzyme expressions were determined. Results： GnRH-Ⅰ and -Ⅱ agonists significantly stimulated murine Leydig cell steroidogenesis 60%-80% in a dose- and time-dependent manner （P 〈 0.05）. The mRNA expressions of steroidogenic acute regulatory （STAR） protein, P450scc, 3β-hydroxysteroid dehydrogenase （HSD）, but not 17β-hydroxylase or 17β-HSD, were significantly stimulated by both GnRH agonists with a 1.5- to 3-fold increase （P 〈 0.05）. However, only 3β-HSD protein expression was induced by both GnRH agonists, with a 1.6- to 2-fold increase （P 〈 0.05）. Conclusion： GnRH directly stimulated murine Leydig cell steroidogenesis by activating 3β-HSD enzyme expression.展开更多
Although gonadotropin releasing hormone (GnRH), GnRH like molecule, and GnRH receptor (GnRH R) have been reported to exist in several tissues other than brain or anterior pituitary, there are no reports concerning ...Although gonadotropin releasing hormone (GnRH), GnRH like molecule, and GnRH receptor (GnRH R) have been reported to exist in several tissues other than brain or anterior pituitary, there are no reports concerning GnRH or GnRH R gene expression in a normal pancreatic gland. In order to define the production of GnRH as well as GnRH R in the pancreatic gland, we examined their gene expression in various developmental stages of rat pancreas using the reverse transcriptase polymerase chain reaction (RT PCR). GnRH mRNA transcripts were found in pancreas of male and female rats at different ages, expressing at about the same level, whereas GnRH R mRNA transcripts could not be detected in any rat pancreatic gland samples. These results suggest a possible biological role of GnRH in rodent pancreas.展开更多
Background and objective:Gonadotropin-releasing hormone (GnRH) plays an important role in the regulation of ovarian function and ovarian cancer cell growth. In this study, we determined whether administration of the G...Background and objective:Gonadotropin-releasing hormone (GnRH) plays an important role in the regulation of ovarian function and ovarian cancer cell growth. In this study, we determined whether administration of the GnRH agonist (GnRHa), triporelin, prior to cisplatin treatment affects cisplatin and/or prevents cisplatin-induced ovarian damage. Methods:nu/nu mice were injected with ovarian cancer OVCAR-3 cells intraperitoneally. After two weeks, the mice were treated with saline (control), cisplatin, GnRHa, or cisplatin plus GnRHa for four weeks. At the end of the experimental protocol, blood, tumor, ovary, and uterine tissues were resected for hematoxylin and eosin (H&E) staining, immunohistochemical analyses of Ki67, nuclear factor-κB (NF-κB), and caspase-3, transmission electron microscopy of apoptosis, or enzyme-linked immunosorbent assay (ELISA) analyses of anti-Mullerian hormone (AMH). Results:Cisplatin treatment effectively inhibited tumor growth in mice treated with human ovarian cancer cells; however the treatment also induced considerable toxicity. Immunohistochemical analyses showed that Ki67 expression was reduced in cisplatin-treated mice compared to control (P<0.05), but there was no statistically significant differences between cisplatin-treated mice and cisplatin plus GnRHa-treated mice (P>0.05), while expressions of NF-κB and caspase-3 were reduced and induced, respectively, in cisplatin-treated mice and cisplatin plus GnRHa-treated mice. Apoptosis occurred in the GnRHa, cisplatin, and cisplatin plus GnRHa-treated mice, but not in control mice. Ovaries exposed to GnRHa in both GnRHa mice and cisplatin-treated mice (combination group) had significantly more primordial and growth follicles and serum levels of AMH than those in the control mice and cisplatin-treated mice (P<0.05). Conclusions:Administration of GnRHa to mice significantly decreased the extent of ovarian damage induced by cisplatin, but did not affect the anti-tumor activity of cisplatin.展开更多
文摘Aim： To study the effect and mechanism of gonadotrophin-releasing hormone （GnRH） on murine Leydig cell steroidogenesis. Methods： Purified murine Leydig cells were treated with GnRH-Ⅰ and -Ⅱ agonists, and testosterone production and steroidogenic enzyme expressions were determined. Results： GnRH-Ⅰ and -Ⅱ agonists significantly stimulated murine Leydig cell steroidogenesis 60%-80% in a dose- and time-dependent manner （P 〈 0.05）. The mRNA expressions of steroidogenic acute regulatory （STAR） protein, P450scc, 3β-hydroxysteroid dehydrogenase （HSD）, but not 17β-hydroxylase or 17β-HSD, were significantly stimulated by both GnRH agonists with a 1.5- to 3-fold increase （P 〈 0.05）. However, only 3β-HSD protein expression was induced by both GnRH agonists, with a 1.6- to 2-fold increase （P 〈 0.05）. Conclusion： GnRH directly stimulated murine Leydig cell steroidogenesis by activating 3β-HSD enzyme expression.
基金the National Natural Sciences Foundationof China(No. 39770 388)
文摘Although gonadotropin releasing hormone (GnRH), GnRH like molecule, and GnRH receptor (GnRH R) have been reported to exist in several tissues other than brain or anterior pituitary, there are no reports concerning GnRH or GnRH R gene expression in a normal pancreatic gland. In order to define the production of GnRH as well as GnRH R in the pancreatic gland, we examined their gene expression in various developmental stages of rat pancreas using the reverse transcriptase polymerase chain reaction (RT PCR). GnRH mRNA transcripts were found in pancreas of male and female rats at different ages, expressing at about the same level, whereas GnRH R mRNA transcripts could not be detected in any rat pancreatic gland samples. These results suggest a possible biological role of GnRH in rodent pancreas.
基金Project (No. 7002691) supported by the Guangdong Provincial Natural Science Foundation of China
文摘Background and objective:Gonadotropin-releasing hormone (GnRH) plays an important role in the regulation of ovarian function and ovarian cancer cell growth. In this study, we determined whether administration of the GnRH agonist (GnRHa), triporelin, prior to cisplatin treatment affects cisplatin and/or prevents cisplatin-induced ovarian damage. Methods:nu/nu mice were injected with ovarian cancer OVCAR-3 cells intraperitoneally. After two weeks, the mice were treated with saline (control), cisplatin, GnRHa, or cisplatin plus GnRHa for four weeks. At the end of the experimental protocol, blood, tumor, ovary, and uterine tissues were resected for hematoxylin and eosin (H&E) staining, immunohistochemical analyses of Ki67, nuclear factor-κB (NF-κB), and caspase-3, transmission electron microscopy of apoptosis, or enzyme-linked immunosorbent assay (ELISA) analyses of anti-Mullerian hormone (AMH). Results:Cisplatin treatment effectively inhibited tumor growth in mice treated with human ovarian cancer cells; however the treatment also induced considerable toxicity. Immunohistochemical analyses showed that Ki67 expression was reduced in cisplatin-treated mice compared to control (P<0.05), but there was no statistically significant differences between cisplatin-treated mice and cisplatin plus GnRHa-treated mice (P>0.05), while expressions of NF-κB and caspase-3 were reduced and induced, respectively, in cisplatin-treated mice and cisplatin plus GnRHa-treated mice. Apoptosis occurred in the GnRHa, cisplatin, and cisplatin plus GnRHa-treated mice, but not in control mice. Ovaries exposed to GnRHa in both GnRHa mice and cisplatin-treated mice (combination group) had significantly more primordial and growth follicles and serum levels of AMH than those in the control mice and cisplatin-treated mice (P<0.05). Conclusions:Administration of GnRHa to mice significantly decreased the extent of ovarian damage induced by cisplatin, but did not affect the anti-tumor activity of cisplatin.
