Circulating levels of estradiol 17-β and progesterone vis à vis nitric oxide and nitric oxide synthase at and around oestrus in cycling buffaloes

Abstract

The present study was designed to measure the circulating levels of estradiol 17-β and progesterone vis à vis nitric oxide (NO) and nitric oxide synthase (NOS) levels at and around oestrus in cycling buffaloes. Blood samples were collected −2, −1, 0, +1 and +2 days of oestrus cycle from cycling buffaloes and analyzed for NO, NOS, estradiol 17-β and progesterone levels. In present study, the levels of NO did not show significant (P < 0.05) variation from −2 day to day of oestrus then decreased significantly and ranged between 11.4 and 26.4 μM/L. The NOS concentration showed similar pattern as exhibited by NO in buffaloes and ranged from 0.56 to 1.28 U/L. The estradiol 17-β in buffaloes gradually increased and peaked at day of oestrus and ranged between 1.9 and 29.32 pg/ml and the pattern was observed almost similar to those of NO and NOS. The levels of progesterone decreased from −2 day to day of oestrus and then increased and ranged between 0.01 and 0.42 ng/ml. The present study generates data of NO, NOS, estradiol 17-β and progesterone at and around oestrus in buffaloes and that is of practical importance for clinical and experimental interpretations.