Insulin-Like Growth Factor-I as a Follicular Growth Promoter during Early Pregnancy in Thoroughbred Mares

Journal of Veterinary Medical Science

Yoh-Ichi MIYAKE⁵  Refaat DERAR³  Shigeyuki HARAMAKI²  MD. Shafiqul HOQUE⁵  Tsutomu HASHIZUME¹  Gen WATANABE⁴  Takeshi OSAWA⁵  Kazuyoshi TAYA⁴ 

[1] Laboratory of Animal Production, Faculty of Agriculture, Iwate University;Shadai Corporation, Shiraoi Farm;Department of Theriogenology, Faculty of Veterinary Medicine, Assiut University;Laboratory of Veterinary Physiology, Tokyo University of Agriculture and Technology;Laboratory of Theriogenology, Faculty of Agriculture, Iwate University

关键词: early pregnancy;    follicle;    IGF-I;    mare;   

DOI  :  10.1292/jvms.67.19

学科分类：兽医学

来源: Japanese Society of Veterinary Science

【 摘 要 】

References(20)Cited-By(3)To elucidate the physiological role of insulin-like growth factor-I (IGF-I) during early pregnancy in mares, number of ovarian follicles was monitored ultrasonically during different stages of the first trimester of pregnancy in 36 thoroughbred mares. From 9 of 36 mares, blood samples were collected weekly from the mating day till the end of the first trimester of pregnancy and plasma IGF-I profiles were examined with other hormones, like follicle stimulating hormone (FSH), luteinizing hormone (LH), ir-inhibin, progesterone and estradiol-17β. Plasma IGF-I level fluctuated throughout the studied period with four peaks on the 7th, 28th, 49th and 84th days of pregnancy. Plasma IGF-I showed a positive correlation with plasma FSH (P<0.05), whereas no correlation was found with other hormones during the studied period. Plasma IGF-I had no correlation with the foetal size, but positive correlation with the number of large (> 30 mm) and medium (10-30 mm) follicles. These results suggested that IGF-I might produce from the medium and large follicles during early pregnancy and promote to develop their growth via pituitary FSH mediated effects in the mares.

【 授权许可】

Unknown