Immunomorphological Evaluation of Pregnant Rats Exposed to Passive Smoking and their Offspring (Neuroendocrine Aspects)

Abstract

The aim of the study was to comprehensively assess histological parameters of the hypothalamic neurosecretory and immune systems in pregnant rats exposed to passive smoking and their offspring.Material and methods. We studied morphological and immunological parameters of pregnant Wistar rats exposed to passive smoking and those of the control group, as well as their offspring. The obtained material was processed using histological, immunohistochemical, morphometric and immunological methods.Results. The results obtained demonstrated that in rats exposed to passive smoking, the sizes of neurosecretory cells (NSCs) of the supraoptic (SO) and paraventricular (PV) nuclei of the hypothalamus increased, the number of p53 positive NSCs increased, and bcl-2 protein expression decreased. Tobacco smoking caused formation of a proaptotic dominant in the neurosecretory cells of the supraoptic and paraventricular nuclei of the hypothalamus. Passive smoking led to a decreased body weight, a decreased number of thymocytes and myelokaryocytes in pregnant rats. In young rats born from the animals exposed to passive smoking, there was a slowdown in the processes of postnatal differentiation of the adrenal cortex (fascicular zone) with preservation of the extended zone of the fetal cortex. Notably, histo- and morphogenesis both in the organs of the primary (thymus) and secondary (spleen, lymph nodes) links of immunogenesis were delayed. In such young rats, a decreased body weight, thymus, number of thymocytes and splenocytes were recorded.Conclusion. Total results of the study evidence that passive smoking causes immunosuppressive changes in pregnant rats and their offspring combined with delayed postnatal histogenesis and proapoptotic manifestations in the nonapeptide-dergic hypothalamicpituitary adrenocortical system, which can be regarded as an unfavorable factor in the implementation of the neuroendocrine regulative mechanisms of adaptogenesis processes.