Effects of passive immunization of goats against inhibin on follicular development, hormone profile and ovulation rate

Abstract

This study was conducted to investigate the effect of immunoneutralization against endogenous inhibin on FSH secretion and ovulation rate, with the aim of developing a new superovulation method using inhibin antiserum in goats. Two groups of goats received an i.v. injection of either 10 ml normal goat serum (control; n = 6) or 10 ml inhibin antiserum developed against [Tyr(30)]-inhibin alpha (1-30) (n = 6) 48 h before treatment with prostaglandin F(2alpha) (PGF(2alpha)). Blood samples were collected at 6 h intervals and ovaries were examined each day using a B-mode ultrasound scanner equipped with a 7.5 MHz transducer during the experimental period. Immunization against inhibin resulted in a four- to fivefold increase (P < 0.01) in plasma concentrations of FSH. After luteolysis, plasma concentrations of oestradiol increased markedly to reach a preovulatory peak, which was about two times higher (P < 0.01) than that of the controls. The treatment was accompanied by a significant increase in the total number of follicles of > or = 3 mm in diameter at 24 (8.2 +/- 0.4 in inhibin antiserum group versus 4.8 +/- 0.3 in control group) and 96 h later (13.5 +/- 1.0 in inhibin antiserum group versus 5.3 +/- 0.6 in control group). The ovulation rate was significantly (P < 0.01) higher in goats treated with inhibin antiserum (4.2 +/- 0.5; n = 6) than in control goats (1.8 +/- 0.3; n = 6). These results indicate that inhibin is an important factor in the regulation of FSH secretion in goats and demonstrate that passive immunization against inhibin at 48 h before treatment with PGF(2alpha) induces the development of more follicles and increases ovulation rate. Thus, inhibin antiserum treatment may be an alternative to the use of exogenous gonadotrophins for induction of superovulation in goats.

Evaluation of attenuated Salmonella choleraesuis-mediated inhibin recombinant DNA vaccine in rats

“…In addition, the attenuated bacteria vector can also act as a vaccine for Salmonella, which infects both humans and animals, resulting in enteritis and blood poisoning. (Medan et al, 2003a;Sasaki et al, 2006). Our results showed that the recombinant vaccine increased the amount of corpora lutea in rats, consistent with our previous study that the naked inhibin DNA vaccine can augment the twinning rate in sheep and improve litter size in rats (Han et al, 2008).…”

Effect of hyperandrogenism on ovarian function

“…PGs modulate different ovarian functions, such as the rupture of ovarian follicles associated with ovulation (Husein & Kridli 2003, Medan et al 2003 and luteolysis (Motta et al 1999(Motta et al , 2001. We have previously reported that hyperandrogenism induces a pro-inflammatory status mediated by the PG system in both mice (Luchetti et al 2004, Elia et al 2006 and rats (Amalfi et al 2012).…”

Cyclic changes in messenger RNAs encoding inhibin/activin subunits in the ovary of the golden hamster (Mesocricetus auratus)

“…Although activins were initially isolated as gonadal peptides that stimulate FSH secretion (de Jong 1988, Ying 1988, they are now known to be multifunctional growth factors that are very important for vertebrate development and other physiological events , Hillier & Miro 1993, Findlay et al 2001. Inhibins are known to be major FSH-suppressing factors in the female in mammals (Rivier et al 1986, Culler & Negro-Vilar 1989, Kaneko et al 1995, Kishi et al 1999, Medan et al 2003 and are important for determining species-specific ovulation rate . They are mainly expressed in granulosa cells of the ovary in adult cyclic females of various mammals, such as rats (Merchenthaler et al 1987, Meunier et al 1988, golden hamsters (Kishi et al 2002), Siberian hamsters (Phodopus sungorus) (Kenny et al 2002a,b), sheep (Engelhardt et al 1993), pigs (Rokukawa et al 1986), cows (Rokukawa et al 1986), monkeys (Schwall et al 1990) and humans (Merchenthaler et al 1987).…”