Histological and histochemical investigations on the structural aspects of the testis of adult brown bear (Ursus archtos arctos)

Abstract

The study carried out on mature Brown Bears brought to the Wild Life Research Center of Uludag University, Faculty of Veterinary Medicine, for rehabilitation. The bears were castrated before sending them to a wild life sanctuary for preventing their over breeding. Structural differences in the testes of bears in sexually active and inactive state were shown by using histological, histochemical and histometrical methods. Testes were cut longitudinally into two pieces and the lengths were measured. The tissue pieces taken from four different parts of one piece, fixated in buffered formalin to demonstrate the parenchyma and excretory ducts. The 5-7 micron sections cut from paraffin blocks, stained with Crosmon's Triple stain for morfological features, Gomori's silver stain and Pinkus' orcein-giemsa stain for connective tissue fibers, Me Manus' periodic-acide schiff technique for glycosaminoglycans. The 10-15 micron cryostat sections were stained with Oil-red O stain method for lipids. The average diameters of seminiferous tubules were measured with the method of Gill and Leighton. The average lengths of testes in active state were found longer than in inactive state. In the active state tunica albuginea of testes was thicker than in the inactive state. In the sexually active state it was observed that the walls of tubuli seminiferi contorti were made up of 2-4 lines of cells while they were contracted and the wall was made up of 1-2 cell lines in the inactive state. The average diameters and thickness of epithelium lining ductuli efferentes, ductus epididimidis and ductus deferens were increased in the active state.