Functional histology of the ovarian follicles as determined by follicular fluid concentrations of steroids and IGF-1 in Camelus dromedarius

In dromedary camel:
• Estrogenic large follicles have suppressive effects on the growth of other follicles.
• Gross opaqueness of the surface follicle is a reliable sign for follicular atresia.
• High follicular fluid estradiol-17β concentrations are a sign of health of follicles.

Ovaries were collected from sexually mature non-pregnant dromedary she-camels. Follicles 6 to 19 mm in diameter per pair of ovaries were randomly selected and classified into clear (n = 30), or opaque (n = 14) based on macroscopic examination of the follicle surface, and then were divided into four classes: clear follicles with 6– 9.9 and 10–19 mm diameter; opaque follicles with 6– 9.9 and 10–19 mm diameter. Follicular fluid (FF) was aspirated for measurement of estradiol-17β, progesterone and IGF-I concentrations, and then a section of tissue through the exposed surface of the follicle wall was removed and fixed in and processed for histological examination. Mean (±SE) number of clear follicles observed on the ovaries that contained a large dominant follicle was less than that on the ovaries which contained a large atretic follicle (p < 0.05; 2.6 ± 1 vs 8.6 ± 0.6). In conclusion, the estrogenic large follicles have suppressive effects on the growth of other follicles.