Histochemical studies on thyroid and parathyroid glands of pig (Sus scrofa)

The present histochemical study on thyroid and parathyroid glands was conducted on six Large White Yorkshire pigs. Histochemically, the lining epithelium of follicles of the thyroid gland, along with the basement membrane and thyrocolloid, showed intense positive reaction for PAS, while the capsule showed mild reaction for PAS-AB. The follicular cells and parafollicular cells showed mild positive activity,and the thyrocolloid showed intense positive activity for protein. The calcium was deposited in the cytoplasm of parafollicular cells, thyrocolloid and interfollicular connective tissue. Intense acid phosphatase activity was noticed in the blood vessels and interstitial connective tissue of the capsule and basement membrane of the follicular lining epithelium. Intense alkaline phosphatase activity was noticed in blood vessels of interstitial connective tissue and the basement membrane of the follicular lining epithelium. The fat deposition was noticed in the capsule, trabeculae and interlobular connective tissue. In the parathyroid gland, the colloid substance of mixed follicles showed an intense positive reaction for PAS. The secretory granules of chief cells were positive for PAS and PAS-AB proteins.