The effect of deslorelin acetate on the oestrous cycle of female guinea pigs

Abstract

Deslorelin acetate, a GnRH agonist, is commonly used to prevent folliculogenesis in several species. However, little is known of the effect of deslorelin acetate implants on the oestrous cycle of female guinea pigs. Fifteen intact healthy female guinea pigs were investigated in this study. Signs of sexual behaviour, the presence of a vaginal membrane along with plasma concentrations of oestradiol (E2)and progesterone (P4), were monitored during two consecutive oestrous cycles. At the beginning of the third oestrous cycle each guinea pig was administered an implant of the GnRH analogue, deslorelin acetate, (4.7 mg). When compared to the untreated state, deslorelin implantation was associated with altered signs of oestrus. The average time to opening of the vaginal membrane was delayed. After opening, the vaginas were found to be variably opened and closed. A significant reduction in P4 (to less than 1.0 ng/ml) and cessation of P4 cyclical variation was observed. Plasma E2 remained high during the whole experimental period. This study shows that cessation of the oestrous cycle by the deslorelin implant might be useful in preventing pregnancy in guinea pigs.

Keywords

• guinea pig
• deslorelin
• progesterone
• oestradiol
• oestrous cycle