Involvement of insulin and growth hormone (GH) during follicular development in the bovine ovary
| Autor: | Masa Tetsuka, Chiho Kawashima, Chiaki Murayama, Akio Miyamoto, Natsuko Sudo, Takashi Shimizu |
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| Rok vydání: | 2008 |
| Předmět: |
endocrine system
medicine.medical_specialty Time Factors medicine.medical_treatment Ovary Growth hormone receptor Endocrinology Ovarian Follicle Food Animals Internal medicine Follicular phase medicine Animals Insulin RNA Messenger Cells Cultured Estradiol biology Receptors Somatotropin General Medicine Follicular fluid Receptor Insulin Follicular Fluid Drug Combinations Insulin receptor medicine.anatomical_structure Follicular Phase Gene Expression Regulation Theca Growth Hormone biology.protein Cattle Female Animal Science and Zoology Follicle Stimulating Hormone hormones hormone substitutes and hormone antagonists Hormone |
| Zdroj: | Animal Reproduction Science. 106:143-152 |
| ISSN: | 0378-4320 |
| Popis: | Insulin and growth hormone (GH) play critical roles in the process of follicular development and maturation. However, the involvement of insulin receptor (IR) and GH receptor (GHR) during follicular development is not well understood. The aim of this study was to investigate the expression of IR and GHR mRNAs in the granulosa cells (GCs) and theca tissues (TCs) of the follicle at different developmental stages (preovulatory dominant follicles, POFs; estrogen-active dominant follicles, EADs; estrogen-inactive dominant follicles, EIDs; and small follicles, SFs), and second, to examine the effects of follicle-stimulating hormone (FSH) and estradiol (E2) on the expression of IR and GHR genes in cultured bovine GCs. Although the concentration of insulin in follicular fluid (FF) was constant at all developmental stages, the GH concentration in FF was significantly increased in the EAD and POF compared with the EID. IR mRNA in GCs and TCs was significantly increased in the POF compared with other follicles. Regarding GHR expression, significant increases of mRNA expression were observed in GCs of EAD compared to those of SF, EID and POF. GHR mRNA in TCs was significantly decreased in the SF compared with other follicles. In cultured GCs, FSH, but not E2, stimulated the expression of IR and GHR genes. Our results suggest that the increase in the expression of GHR may be a turning point for follicles to enter the ovulatory phase during final follicular development and that the insulin system may support the maturation of preovulatory follicles. |
| Databáze: | OpenAIRE |
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