The interrelationship between the occurrence of oversized follicles and the peripheral and intra-follicular concentrations of E2, P4, FSH, and LH in female dromedary camels

Abstract

The present study aimed to clarify the phenomenon of presence of larger than normal follicles (OVGF) in female dromedary camels. Females with OVGF (n=125) were examined by manual palpation and ultrasonography. Accordingly, the OVGF were subdivided into those with thin walls and clear hypoechogenic content (OVGF-TH, n=18) and those with thick walls and fibrous trabeculae (OVGF-TK, n=107). Transvaginal follicle aspiration was performed in females with OVGF and from a control group with growing follicles (1-2 cm in diameter, GF group, n=5). Serum was collected at the same time of follicle aspiration and analyzed for Follicle-stimulating hormone (FSH), luteinizing hormone (LH), progesterone (P4) and estradiol-17β profiles (E2). The follicular fluid (FF) was analyzed for E2 and P4. The results showed that mean E2 concentration in FF and serum were lower in OVGF-TH and OVGHTK groups than in the GF group (P < 0.05). Difference between OVGF-TH and OVGH-TK groups was not significant. P4 in FF did not significantly differ among groups. Positive correlation was found between E2 in FF and E2 in serum (r = 0.495, r = 0.03). Mean FSH concentration in serum was higher in OVGF-TH and OVGH-TK groups than in the GF group (P = 0.03). Mean LH concentration was non-significantly (P=0.1) greater in OVGF-TH and OVGH-TK groups than in the GF group. In conclusion, female dromedary camels with OVGF had endocrine characteristics differed from camels with no OVGF. It seems that the high FSH and/or LH concentration(s) stimulated the continuing growth of the developing follicles to reach these large sizes, suggesting that the phenomenon of OVGF in camels is a pathological finding.