Passive immunization against inhibin raises the plasma concentration of FSH in cycling Murrah buffaloes

Abstract

The effects of inhibin antisera on the circulatory levels of gonadotrophins, luteinzing hormone (LH) and follicle stimulatinghormone (FSH) were studied in 4 cycling Murrah buffaloes in the age group of 3 ½ to 4 years. Saline (2.5 ml) was injected s/ctwice at 12 hr interval on day 16 of the cycle and inhibin antisera dissolved in 2.5ml/saline was administered similarlyduring the succeeding cycle into these animals. Blood samples were collected at 6 hr interval starting from day 17 of thecycle till the estrus and at 15 min interval for 4 hr on the day of estrus. Mean LH levels measured during, the proestruswere low and did not show any significant difference between the treatments. LH leveI showed a peak as excepted on the  dayof estrus but did not show any significant difference between the treatments. Mean FSH levels measured after inhibin antiseraadministration in buffaloes showed a significant increase (P<0.01) both in the proestrus and estrus compared to the levels inthe saline-treated buffaloes. The results suggested that passive immunization against inhibin preferentially increases FSHlevels but no effect was seen on LH-levels in cycling Murrah buffaloes.