Follicular attributes and intra-follicular nitric oxide and ascorbic acid concentrations in cyclic and acyclic buffaloes during summer season

Morphological attributes of follicles and intrafollicular concentrations of nitric oxide (NO) and ascorbic acid (AA) were investigated in ovaries collected from cyclic and acyclic buffaloes slaughtered at an abattoir during summer. Results indicated lower (P<0.001) diameter of the largest follicle and reduced follicular fluid yield in acyclic (5.88 ± 0.61 mm and 0.20 ± 0.03 ml, respectively) than in cyclic (9.81 ± 0.30 mm and 0.44 ± 0.03 ml, respectively) buffaloes. Higher (P<0.001) concentrations of NO and lower (P<0.001) concentrations of AA were observed in acyclic (467.6 ± 42.73 μM/ml and 9.67 ± 0.51 μg/ml, respectively) than in cyclic (265.46 ± 16.28 μM/ml and 13.09 ± 0.36 μg/ml, respectively) buffaloes. Concentrations of NO and AA showed a significant (P<0.05) variation across the stages of estrous cycle. In conclusion, the study indicated a suppressed growth of the largest follicle, reflected in lower diameter and follicular fluid volume, in acyclic animals during summer. An altered NO and AA balance in the follicular microenvironment probably impairs the follicular growth and development leading to acyclicity in buffaloes during summer.