Abstract
Chronic toxicity of carbamate pesticide (1-Naphthyl-N-methyl carbamate : Sevin) was studied in four wister male rats and the results were compared with four controls treated by saline in the same route of administration. Both treated and controls were feeded and kept under the same environmental condition. The drug was orally administrated (3 mg/rat/week) for one year. Total doses of administration were approximately 750 mg/kg per rat. Histopathological study of endocrinological organs of pancreas, adrenal gland and testis were made. Conventional hematoxylin and eosin staining were made after sacrifice by cervical dislocation at the termination of the administration. In order to quantitate the ratio between the area of Langerhans islets and all pancreatic tissue, histometry by means of a newly developed image-analyzer with built in computer (Imagelyzer) was used. At least, four different cross sections at the tail of pancreas in each animal were examined and they were photorapghed and analyzed. Significant reduction of the area of Langerhans islets to the total area of the tissue was noted in two of four treated animals when compared with the controls. In two out of four treated rats, in adrenal cortex, broadona reticularis with occasional vacuolated cells between zona fasciculata and zona reticularis were the major changes. The reduction in the number of spermatogonia and spermatozoa was noted in seminifercus tubules of the testes of the treated animals. These were not seen in the controls. The results indicated that Sevin involved rat's endocrine organs when chronically treated.
