Opiate bioneutralization and its effects on hypophysial gonadotrophins in cycling Murrah buffaloes

Abstract

The effects of opiate bioneutralization on circulating luteinizing and follicle stimulating hormones were studied during luteal phase of 6 cycling Murrah buffaloes using an antiopiate naloxone. Saline was infused into the animals through the jugular vein for 4 hr @ 0.66 ml/min on day 11 of the cycle, and naloxont!hydrochloride (1.5 mg/ kg body wt.) dissolved in saline was infused at the same rate on day 14 of the cycle. Naloxone treatment increased LH levels significantly (P< 0.01) over the saline treatment during the infusion. Mean of LH pulses though high in the naloxone treatment (3.16/4 hr) was not significantly different (rom the saline treatment (2.5/4 hr). But mean magnitude showed a significant difference in naloxone treatment (2.07±0.09 ng/ml) compared to the saline treatment (1.33±0.05 ng/ml). However. LH in post-infusion samples collected at hourly interval for 4 hr did not show any significant difference over the levels in the saline treatment. FSH levels did not show any significant difference between treatments. The above results showed that naloxone is a short acting anti opiate that can increase LH levels for short periods in animals primed with progesterone.