Adrenal histochemistry of the freshwater teleost Labeo rohita (Ham.)

Abstract

In Labeo rohita the adrenal homologue is situated around the cardinal vein and its branches, in the lymphoidal pronephric head kidney. Although a majority of medullary cells are arranged close to the wall of the blood vessels, some are seen among the cortical cells also. They exhibit positive chromaffin reaction. Two types of medullary cells could be differentiated with the aid of dichromate and glutaraldehyde-silver techniques. After administration of reserpine, marked depletion was noticed among the glutaraldehyde, and dichromate positive cells. The medullary cells give a positive reaction to PAS after Zenker-formol fixation. They intensely react to the ascorbic acid test. The cortical cells are positive to total lipids and phospholipids. In metopirone treated fishes there is a general reduction in the sudanophilic nature of these cells. Δ5-3β HSDH and G-6-PD activity in the cortical cells indicates that they are capable of steroid biosynthesis. Alkaline phosphatase is moderate in the nuclei and weak in the cytoplasm of the medullary cells whereas it is intense in the cortical cells. Acid phosphatase activity was intense in the nuclei and moderate in the cytoplasm of cortical cells whereas it was moderate in nuclei and weak in the cytoplasm of the medullary components. The adrenal components give a positive reaction to monoamine oxidase.