MORPHOFUNCTIONAL STATE OF THE ADRENAL GLANDS IN LABORATORY ANIMALS UNDER EXPERIMENTAL INTOXICATION WITH CYPERMETHRIN

The research objective was to evaluate the morphofunctional state of the adrenal glands in laboratory animals in conditions of acute and chronic intoxication with cypermethrin. Studies were performed on 140 male rats of the Wistar line. To simulate an acute intoxication cypermethrin was single injected into the stomach in a dose of half of LD₅₀ followed by observation of the animals for 30 days. In the study of chronic intoxication cypermethrin was administered to rats in a dose of 1/100 of LD₅₀. The experiment has lasted for 120 days.

At the initial stage of the experiment the acute intoxication of rats with cypermethrin caused hyper- and then hyposecretion of adrenocorticotropic hormone. The content of progesterone in the blood serum and adrenal tissue decreased in animals. During the first three days after the poisoning there was an increase in the concentration of corticosterone in the blood serum. To the end of the 7th day the concentration of this hormone in adrenal tissue decreased sharply and did not reach the control background after a month. Chronic intoxication with cypermethrin caused hypersecretion of adrenocorticotropic hormone for two months with the subsequent normalization of its level in the blood. The disturbance of progesterone synthesis in the adrenal glands during chronic intoxication is indicated by fluctuation of its concentration in blood 30 days after the start of the experiment. There was found high level of corticosterone in blood and adrenal glands for two months, and then it decreased to a control level. Morphological criteria for amplification and then suppression of adrenal function are the dimension of endocrine cells and their nuclei, the intensity of cell vacuolation suggesting the degree of lipids accumulation, and the severity of blood filling in the vessels of the beam and reticular zones.