PARENT SESSION
Follicular Development

HEXARELIN GIVEN ALONE FOR THREE DAYS DOES NOT AFFECT FOLLICULAR DEVELOPMENT.

Conley, Lisa¹, Kaul, Elizabeth¹, Trewin, Amanda², Hutz, Reinhold², ^{1 2}

ABSTRACT- The growth hormone-releasing peptides (GHRPs) constitute a class of synthetic compounds derived from enkephalin that specifically release GH, bind with a unique receptor, and whose endogenous counterpart, ghrelin, has been identified recently. Because a number of previous reports have suggested that growth axis hormones play a role in ovarian function, we characterized what effect in vivo exposure to Hexarelin, a GHRP, had on ovarian follicular development. Female Sprague-Dawley rats (60 days of age) exhibiting at least 2 regular 4-day estrous cycles were used in this study. Rats received either 100 g/kg of Hexarelin (n=3) or the same volume-for-weight of saline (n=3) subcutaneously twice daily for 3 days starting 72 hours prior to an anticipated proestrus. Rats were then euthanized on the morning of proestrus, and their right ovaries harvested and fixed in Bouins solution. Ovaries were dehydrated, embedded in paraffin and fully sectioned (10 m). The total number and areas of follicular sections containing germinal vesicles (subclassified as pre-antral, early-antral or antral) were determined following hematoxylin and eosin staining. The average number of qualifying follicles that were pre-antral, early-antral or antral did not differ between treatment groups. Although the cross sectional areas of follicles increased significantly as follicles progressed from pre-antral to early- antral to antral stages, the average cross sectional areas of follicles containing germinal vesicles within each category did not differ significantly between rats treated with saline and those treated with Hexarelin. Although these data suggest that Hexarelin given alone for three days does not alter ovarian follicular development, further study is needed to definitively determine whether the GHRPs, like some other GH secretagogues, play a role in ovarian function.

KEY WORDS: follicle, ovary, growth hormone-releasing peptides, Hexarelin