Heart reaction of male and female with streptozotocin induced diabetes on cholinergic impacts

Abstract

The aim: Find out the nature of the changes sensitivity of the heart to the cholinergic influences the development of diabetes depending on gender. Materials and methods: In experiments on adult male and female rats, type 1 diabetes by momentary introduction of streptozotocin at a dose of 60 mg/ kg into the peritoneal cavity was modeled. Animals were examined after 15, 30, 60 and 90 days after introduction of streptozotocin. We studied the sensitivity of cholinoreceptors of sinus node by the intensity of bradycardia with intravenous injection of acetylcholine and electrical stimulation of the peripheral segment of the right vagus nerve. Results: It was established that the intensity of the negative chronotropic effect of heart of males by electric stimulation of the vagus nerve, which depends on the reserves of acetylcholine in the presynaptic section and sensitivity of postsynaptic cholinoreceptors, increased gradually and after 90 days prevailed the output value in 2.2 times. This occurred at the background of a slight (10 %) decrease in response to exogenous acetylcholine that reflected the decrease in sensitivity of cholinoreceptors. In females the maximum increase (in 4.4 times) of the intensity of the negative chronotropic effect of vagus nerve stimulation was observed after 30 days from the start of the experiment. After 90 days, this indicator prevailed the controlled one in 3.3 times, which occurred at the background of heart response decreasing to exogenous acetylcholine (in 1.7 times). Conclusions: Obtained results suggest a more significant change in state of cholinoceptor system of myocardium of females compared with males in the dynamics of development of streptozotocin-induced diabetes.