Electronic microscopic features of parafollicular cells of rat's thyroid gland after 60 days introduction of tartrazine and Mexidol®

Abstract

Objective: To establish the effect of the administration of tartrazine for 60 days, as well as Mexidol® under these conditions, on the structural features of the parafollicular cells of the rat's thyroid gland at the electron microscopic level. Material and methods. Thirty white male rats weighing 200-210 g were divided into five groups six rats each. The Group I is the control; the Groups II and III — rats received tartrazine at a concentration of 750 and 1500 mg/kg for 60 days; the Groups IV and V — under similar conditions Mexidol® was administered at the rate of 50 mg/kg. Qualitative changes in parafollicular cells were studied using electron microscopy, and quantitative changes — by morphometry Results. The fine-grained or fibrous contents were detected in the cisterns of the rough endoplasmic reticulum, and areas of the destroyed matrix in some mitochondria after exposure to tartrazine. The ratio of area eu-chromatin/heterochromatin decreased in the Groups II and III by 5.7% and 56.9%, respectively, and the diameter of secretory granules — by 12.3% and 19%, respectively, compared with the Group I. The ratio of area euchromatin/het-erochromatin increased by 79.6% in Group V, and diameter of secretory granules — by 8.2% and 6.5% in the Groups IV and V respectively, compared with the data of the Groups II and III. Conclusions. The introduction of tartrazine in different doses for 60 days causes dose-dependent qualitative and quantitative changes in the ultrastructure of parafollicular cells, and the introduction of Mexidol® against this background causes a decrease in their severity.