Effect on ovulation rate of passive immunisation of mares against inhibin

Abstract

Summary Fifteen light‐horse mares were monitored daily by palpation and ultrasonography for one oestrous cycle and then randomly divided into two treatment groups. Five mares were treated with 2 litres of normal ovariectomised mare plasma (OVX) on Day 10 after ovulation and 10 mares received 2 litres anti‐inhibin plasma (a‐INH) beginning on Day 10 after ovulation. Mares receiving OVX plasma all had single ovulations after treatment, while 5 of the 10 mares receiving a‐INH plasma had multiple ovulations (mean 1.6 ± 0.2, range 1–3). No significant effect of a‐INH plasma treatment was detected in plasma concentrations of FSH, oestradiol or progesterone. These results demonstrate that passive immunisation of mares with a‐INH plasma can induce multiple ovulations, and thus eliminate the need for daily gonadotrophin treatment or a prolonged series of active inoculations against inhibin.

Equine embryo transfer: review of developing potential

“…In marked contrast, the failure to develop a reliable protocol for pharmacologically inducing multiple ovulation in mares was a major reason for the delayed adoption of ET in equine practice (Squires et al 1999). Although many ovarian stimulatory treatments were tested in mares, few yielded more than an approximate doubling of the ovulation rate (for review see McCue 1996); treatments examined included eCG (Day 1940), GnRH (Ginther and Bergfelt 1990), porcine pituitary FSH preparations (Fortune and Kimmich 1993), growth hormone (Hofferer et al 1991;Cochran et al 1999), equine pituitary gonadotrophin extract (EPE: Douglas et al 1974;Hofferer et al 1991;Dippert et al 1992) and both active (McKinnon et al 1992) and passive (McCue et al 1993) immunisation against inhibin.…”

Embryo recovery rate following superovulation with equine pituitary extract (eFSH®) in mares

“…Da die Sekretion des Glykoproteins Inhibin durch den dominanten Follikel einer Follikelwelle physiologischerweise zu einer Suppression der FSH-Sekretion im Rahmen der Follikelselektion führt (Ginther et al 2001), war ein weiterer Ansatz die Zahl der Ovulationen durch Inhibin Antikörper zu erhöhen. Eine aktive Immunisierung von Stuten gegen Inhibin führte in zwei Studien zwar zu einer Verdopplung der Ovulationen (McKinnon et al 1992, McCue et al 1993, ging jedoch auch mit unerwünschten lokalen Reaktionen am Injektionsort und einer über mehrere Wochen dauernden Behandlung einher, sodass der kommerzielle Einsatz einer Anti-Inhibin Vakzinierung nicht praktikabel schien.…”

Avaliação da dinâmica ovariana, características uterinas, fluxo sanguíneo uterino e ovariano e concentrações séricas de progesterona em éguas no período pós-parto

“…Adicionalmente, a aplicação de anticorpos contra inibina resultou em aumento nos níveis de FSH (GLENCROSS et al, 1994), assim como maior número de folículos dominantes e ovulações (MCKINNON et al, 1992;LASLEY, 1993;NAMBO et al, 1998;BRIANT et al, 2000). Portanto, resultados indicam a participação da inibina como um fator necessário ao processo de desvio folicular, através da redução dos níveis de FSH, assim como proporcionando maior capacidade de resposta ao futuro folículo dominante (GINTHER et al, 2004a).…”