Endocrine Abstracts

Adolescence is one of the most dynamic periods of development, which is highly sensitive to changes induced by stressors. Disruption in hormonal balance associated with stress have a negative impact on puberty and reproductive function. The aim of the work was to study the long-term endocrine effects of chronic pubertal stress in rats. On the 22 postnatal day (PND), the Wistar rats were separated from their mothers and sorted by sex into individual cages, so that animals from different litters were in both the control and experimental groups. The animals were subjected to stress daily in the morning hours from 30 to 45 PND by placing them in cylinders with a diameter of 4.5 cm and a length of 10 cm, equipped with breathing holes. During the stress period and upon its completion, the onset of sexual maturation was recorded in both the control and experimental animals, while observing somatic development. After the stress period ended, the animals were housed in cages in groups of five individuals each. All investigations were conducted on sexually mature rats at the age of 6 months. The weights of gonads and the adrenal glands, and the morphology of the reproductive organs were studied. The quantitative and qualitative indices of the spermatozoa in epididymal washes were determined. The plasma corticosterone levels were measured both at baseline and after one hour of tight restriction. The pubertal chronic stress significantly delayed the sexual maturation of females and adversely affected weight gain in males. In adult animals, pubertal stress did not change the weight and morphology of the gonads, except for slight vacuolation of the spermatogenic epithelium compared to intact ones. The index of spermatogenesis in the experimental group was significantly lower than in the control, due to a decrease in the number of late spermatids, which indicates inhibition of spermatogenesis. Pubertal stress resulted in a 25.9% decrease in sperm count and a 2.4-fold slowing of oxidative-reductive processes in spermatozoa. These animals showed an increase in the number of pathological forms of spermatozoa. A significant decrease in adrenal weight in females and a tendency to a decrease in males were observed. The basal corticosterone levels reduced by 1.7 times in males. Stress reactivity in females and males did not differ from the control. Thus, chronic pubertal stress, under the selected experimental conditions, resulted in adverse long-term sex-specific effects on the reproductive and adaptive systems of adult animals.