ABSTRACT
Induction of hypothyroidism by carbimazole could affect many glands including the pancreas. Brewer's yeast, a herbal product, is recently under research for its possible uses. The aim of the study was to study the microscopic, morphometric, and biochemical changes in the pancreas of hypothyroid rats and to evaluate the role of thyroxin versus Brewer's yeast in amelioration of these changes. Sixty adult male albino rats were randomly divided into five groups. Group I rats served as a control group. Group II rats received carbimazole. Group III rats received carbimazole followed by thyroxin. Group IV rats received carbimazole followed by Brewer's yeast. Group V rats received only Brewer's yeast. At the end of the experimental period, specimens from the pancreas were processed for light and transmission electron microscopic examinations and immunostaining for Ki-67. Biochemical analysis for T3, T4, and insulin was performed. In addition, body mass gain and pancreatic mass were measured. All parameters were statistically analyzed. Group II specimens revealed congestion of blood vessels and cellular infiltration. Acinar cells showed pyknotic nuclei, hyalinization, and vacuolation of the cytoplasm, with few zymogen granules. beta Cells of the islets of Langerhans revealed depletion of organelles and small granules without their characteristic halo. Immunostaining revealed significant decrease in the percentage of Ki-67-positive nuclei. In group III, the acini revealed numerous secretory granules, few vacuoles, and euchromatic nuclei. beta Cells showed secretory granules with the characteristic halo. Group IV revealed less improvement in the histopathological changes as compared with group III. T3, T4, and insulin levels were significantly lower in hypothyroid rats in comparison with the control group, whereas administration of thyroxin showed restoration of these levels to near control values. Hypothyroidism showed a deleterious effect on the histological structure of rat's pancreas. Administration of thyroxin minimized these effects more than administration of Brewer's yeast