Progesterone and nucleic acid contents of buffalo corpus luteum in relation to stages of estrous cycle

Abstract

Study on the variations in weight, concentration of progesterone, DNA and RNA content of corpus luteum was conducted to delineate the Changes during different stages of estrous cycle in buffaloes. Buffalo ovaries with CL (32) were collected from slaughterhouse immediately after slaughter. Stages of reproductive cycle were studied by examining biometry and morphology of corpus luteum. Depending on the colour, vasculature, size and consistency, the stages assigned to corpora lutea were CL-1 (days 1-4 of cycle), CL-2 (days 5-10 of cycle), CL-3 (days 11-17 of cycle) and CL-4 (days 18-20 of cycle). The CL was excised from rest of the ovarian tissue and a weighed quantity of the fraction of luteal tissue was stored at - 20°C for assay of progesterone. The size and weight of CL increased with the growth of CL till it attained peak stage of its development and then size and weight started declining with its regression. CL extract mean progesterone concentrations were 7 .27±0.95 µg/g, 8.98:±:0.67 µg/g 11.44± 1.42 ) µg/g and 3.99±0.71 µg/g in the first, second, third and fourth stage CL respectively. The DNA and RNA contents of CL were 1.18±0.13 and 4.69±0.41 mg/g; 0.98±0.11 and 2.96±0.13 mg/g; 1.33±0.24 and 2.56±0.33 mg/g; 1.39±0.17 and 3.11±0.79 mg/g during the first, second, third and fourth stage of estrous cycle respectively. Functional activity of corpus luteum was maximum during third stage of the estrous cycle in buffaloes as compared to other stages.