Impaired epididymal function and changes in thyroid and adrenal glands morphology of heat stressed rats

Abstract

Twenty mature male albino rats randomly assigned to two groups were used for the study. In group A rats, hyperthermia was induced exogenously by exposure to the sun, while group B rats were kept under a shade. The duration of the study was 28 days. At the end of the study the effects of heat stress on body weight (BW), body mass index (BMI), feed intake (FI), epididymal sperm reserve (ESR), thyroid and adrenal glands morphology were assessed. On day 28, rats that were exposed to heat stress showed significant (p<0.05) decreases in their mean BW and FI when compared to the unexposed. The BMI of the heat stress exposed rats and unexposed rats remained unchanged throughout the period of study. Epididymal sperm reserve was significantly reduced (p<0.05) in the heat stressed rats when compared to the unexposed rats. Histological examination of the thyroid and adrenal glands of the heat stressed rats revealed hypertrophy and hyperplasia of the thyroid and adrenal glands respectively when compared to unexposed rats.

Keywords: Heat stress rat, Body weight, Body mass index, Epididymis, Thyroid gland, Adrenal gland