STATE OF NEUROENDOCRINE SYSTEMS DURING ACTIVATION AND INHIBITION OF CENTRAL CHOLINERGIC SYSTEMS IN BRAIN INJURY

Abstract

The aim of the study was to determine the state of the neuroendocrine systems during the activation and inhibition of the central cholinergic systems (CChS) in traumatic brain injury (TBI) and their effect on mortality and neurological deficit. TBI was applied by the standard method with the free fall of metal weight on the fixed animal head. 161 white male Wistar rats were divided into three groups: in the 1st group, 0.5 ml of Ringer’s solution was injected intraperitoneally before injury (control), in the 2nd – solution of choline alfoscerate at a dose 6 mg/kg (CChS activation), in the 3rd – solution of biperidene hydrochloride at a dose 0.6 mg/kg (CChS blockade). Neurological deficits were assessed using the 100-point Todd scale. In the blood was determined the content of Adrenocorticotropic (ACTH) and Thyroid-Stimulating Hormones, Corticosterone (Cs), free Thyroxine and Triiodothyronine (fT3) by the enzyme immunoassay. It was established that in the acute period of TBI, post-traumatic stress central hypercortisolism is formed with an increase in blood levels of ACTH and Cs, and central hypothyroidism with a predominant decrease in blood fT3. The CChS activation significantly reduced mortality and neurological deficit, which was accompanied by moderate activation of ACTH and Cs and no effect on the thyroid system. The CChS blockade led to the suppression of the post-traumatic reaction of ACTH and Cs activation and the development of deep central hypothyroidism against the significant neurological deficit. Thus, the important role of CChS in the implementation of the post-traumatic stress reaction of the neuroendocrine system has been established, and the possibility of using pharmacological stimulation of the CNS with central cholinomimetics has been substantiated.