EFFECT OF PASSIVE IMMUNIZATION AGAINST INHIBIN-Α, -ΒA, AND –ΒB SUBUNITS ON SERUM GROWTH AND DIFFERENTIATION HORMONES PROFILE IN PREGNANT AND LACTATING PRIMIPAROUS WISTER RATS

Abstract

Transforming growth factor β (TGFβ) superfamily members are closely associated with tissue remodelling events and reproductive processes. The present study aimed to determine the role of immunoneutralization of endogenous inhibin-α, βA, and βB subunits on serum growth growth and differentiation hormones profile during pregnancy, delivery, and lactation periods in primiparous female Wister rats.Eighty four pregnant primiparous female rats were assigned to 4 groups (21 per each). On 5 th and 10 th day of gestation, control was injected with saline (100μl, i.p.), Ta, Tba, and Tbb groups were injected with inhibin-α, βA, and βBantiserum (1µg in 100μl of saline, i.p.), respectively. Each group was allocated to 3 equal subgroups: pregnancy, delivery, and lactation subgroups were sacrificed on day 16 of gestation, 1st day after parturition, and 11 th day of lactation, respectively. At the end of each subgroups period, females were anesthetized, dissected and blood samples were obtained for assessment of inhibin-A, -B, activin-A , -B, -AB, GH, and prolactin levels. Serum inhibin-A concentration in Tbb group increased during pregnancy and delivery among experimental groups. In comparison between periods, Tbb group showed significantly higher level during pregnancy and decreased during delivery and lactation, whereas Ta and Tba groups recorded no difference between periods. Inhibin-B increased in control and Tba groups during pregnancy, whereas lactation period showed higher levels in Ta, Tba, and Tbb groups compared with control. Ta, Tba, and Tbb groups recorded no siginificant differences between pregnancy and delivery periods but they were significantly higher in lactation period.During pregnancy and delivery, Tbb group revealed higher levels of activin-A and lowest level of activin-B concentrations among groups, whereas activin-AB concentration increased in control and Ta groups. In comparison between periods, activin-A concentration was higher at delivery, whereas activin-B and –AB concentrations were higher at lactation. Serum GH, in Ta group, recorded higher level during the three periods among groups. In comparison between periods, the levels of GH and PRL in all groups showed higher levels at delivery followed by lactation and pregnancy.In conclusion, passive im munization against inhibin-α, βA, but not βB subunit, at 5th and 10th day of pregnancy, have ameliorating role on serum growth and differentiation hoemones profile