Development of Embryos in Superovulated Guinea Pigs following Active Immunization against the Inhibin .ALPHA.-Subunit.

Abstract

Abstract.Embryo recovery and subsequent embryonic development from guinea pigs treated with or without Inhibin vaccines were compared to determine the effect of active immunization against the inhibin a-subunit. Twenty female guinea pigs of the Hartley strain were injected 3 times either with 1 ml inhibin vaccine (recombinant ovine inhibin a-subunit in oil emulsion: 50 ,ig/ml, inhibin-immunized group), or 1 ml placebo (saline in oil emulsion; control group) at 4 week intervals. After one estrous cycle following the last injection, females were naturally mated and embryos were collected at 11:00 hr of day 6 of pregnancy (Day 1: sperm in the vaginal smear) for culture in vitro. Active immunization increased the number of corpora lutea (12.6±3.0 vs. 4.6±0.2, P<0.05), recovered embryos (9.8 ± 1.9 vs. 3.6±0.4, P < 0.01) and normal embryos (7.8 ± 1.4 vs. 3.6± 0.4, P < 0.05), although estrous cycle length was not affected (P > 0.05). During subsequent 8 day culture in vitro, most of the recovered embryos formed trophoblast outgrowth; 100% (14/14) and 88.2% (15/17) in control and immunized groups, respectively. High levels of inhibin antibody titers were sustained in the Inhibin-immunized guinea pigs at least for 5 months after the last injection while no antibody titer was detected in the control animals. These results indicate that active immunization against the inhibin a-subunit is a long-acting and efficient method to induce superovulation with normal embryonic development in the guinea pig.

A New Alternative Method for Superovulation Using Passive Immunization Against Inhibin in Adult Rats1

“…Multiple ovulations have been induced successfully by passive immunization against endogenous inhibin in several species such as mice [27], rats [28], hamsters [29], cows [30,31], mares [32], and goats [33]. Furthermore, several studies have shown that oocytes superovulated with immunization against inhibin have the ability to develop normally [27,31,34,35], suggesting that inhibin immunization could be applicable to a wide range of animal species. Although Rivier and Vale [28] reported that increased numbers of pups were obtained after immunoneutralization of inhibin in rats, detailed analysis on embryo quality during peri-implantation was not conducted.…”

Ovarian Response and Hormonal Profiles in Heifers After Immunization and Re-immunization Against Inhibin .ALPHA.-Subunit.

“…Dev. 48: [599][600][601][602][603][604][605] 2002) t is reported that immunoneutralization of inhibin to induce superovulation provides an alternative to current follicle stimulating hormone (FSH) or equine chorionic gonadotropin (eCG) t r eat m en t pr o t o c o ls fo r t h e pr o d uc t i o n o f transferable embryos in mammals [1][2][3][4][5][6][7][8]. Several studies have shown that active immunization of heifers against inhibin α-subunit [9-13] and passive…”

Ovarian Localization of Immunoglobulin G and Inhibin .ALPHA.-Subunit in Guinea Pigs after Passive Immunization against the Inhibin .ALPHA.-Subunit.

“…Although several studies have described how passive immunization against inhibin can enhance follicular developments and ovulation rates in mammals [7][8][9][10], there are as yet no reports on ovarian localization of inhibin antibody. We recently showed that active immunization against the inhibin α-subunit results in an increase in the ovulation rate [6,11,12] and passive immunization against the inhibin α-subunit in the luteal phase results in an increase in the number of small follicles, and plasma FSH in the guinea pig [13,14]. Nevertheless, whether passive immunization against inhibin can increase the ovulation rate and affect follicular development in the follicular phase in guinea pigs has not been documented.…”