Interactions of Autonomic Nervous System, Pituitary- Adrenocortical Axis and Corticotrophin and Cortico- Sterone in the Regulation of Blood Sugar Level in Rats

Autonomic nervous system together with endocrine glands plays in an intricate manner a significant role in the regulation of glucose homoeostasis. The two divisions of autonomic nervous system have opposing actions while several hormones have similar antagonistic actions. The interplay of all these neural and endocrine regulatory mechanisms and the balance of the actions of them finally fine tune the glycaemic level during various physiological states. Many times the action one autonomic system or a hormone depends upon the presence or absence of the opposing factor. The present study presents an account of the effect of autonomic nervous system and adrenal ablations on the corticosterone and corticotrophin (ACTH). Vagotomy (VGX) showed an increase in the corticosterone level whereas ACTH concentration in the serum decreased. In the adrenalectomized rats, a steep decline in corticosterone concentration in serum was accompanied with an increased ACTH level. In the rats which were adrenalectomized and vagotomized together, a similar trend was observed. Chemical sympathectomy (CSX) reduced the corticosterone concentration slightly but the ACTH level increased significantly. When sympathectomy was combined with vagotomy (CSX+VGX) an increase in both corticosterone and ACTH levels was observed. Chemical sympathectomy and adrenalectomy (CSX+ADX) also produced a maximum decrease in corticosterone level and a maximum level of ACTH. Vagotomy (VGX) alone or together with CSX or ADX produced hyperglycaemia while chemical sympathectomy alone or together with adrenalectomy produced hypoglycaemia. In conclusion it could be stated that in rats in which vagotomy was performed singly and in combination with sympathectomy, glucocorticoid secretion increased along with increased corticosterone. Chemical sympathectomy alone or together with adrenalectomy reduced the corticosterone concentration in blood together with hypoglycaemic condition. ACTH concentration by and large was more when corticosterone secretion was decreased.