Faculty of Veterinary Medicine University of Zagreb
Abstract
The structure of the pituitary gland was studied in 3 bottlenose dolphins (Tursiops truncatus) from the Adriatic Sea. This species is legally protected in Croatia. All examined animals died of natural causes and were found stranded along the eastern Adriatic coast. The pituitary gland is a rectangular body suspended at the base of the brain and situated in a depression of the sphenoid bone, clearly identififi ed as sella turcica. The gland was divided into the adenohypophysis and the neurohipophisis, interconnected by thick layer of connective tissue. Pars distalis and pars tuberalis were observed in the adenohypophysis while the pars intermedia was lacking. The pars distalis was built of three main cell types: acidophils, basophils and chromophobes. Most of the acidophils were situated in the centre of the gland while chromophobes occurred dorsal and basophils ventral. Pars tuberalis was composed of cords of polygonal and vacuolated cells, which were in close association with numerous blood vessels. Large numbers of colloid-containing follicles were observed throughout the pars tuberalis. The neurohypophysis of the bottlenose dolphin consisted of unmyelinated nerve fibres among which numerous pituicytes were scattered.Istraživana je građa hipofize u tri dobra dupina (Tursiops truncatus) iz Jadranskog mora. Dobri dupin u Republici Hrvatskoj najstrože je zaštićena životinjska vrsta. Sve istražene životinje uginule su u prirodi i nađene su nasukane duž istočne jadranske obale. Hipofiza u dobroga dupina pravokutnoga je oblika, smještena na osnovici mozga i uložena u udubinu klinaste kosti, prepoznate kao sella turcica. Žlijezda je podijeljena na adenohipofizu i neurohipofizu koje su međusobno povezane debelim slojem vezivnog tkiva. Adenohipofiza dobroga dupina sastoji se od pars distalis i pars tuberalis, dok pars intermedia nedostaje. Pars distalis građen je od tri tipa stanica: acidofilnih, bazofilnih i kromofobnih. Acidofilne stanice u najvećem su broju smještene u središtu žlijezde, dok se kromofobne stanice nalaze dorzalno, a bazofilne ventralno. Pars tuberalis građen je od nizova poligonalnih i ponešto vakuoliziranih stanica koje su blisko vezane uz mnoge krvne žile. Uočen je i velik broj folikula ispunjenih koloidom. Neurohipofiza dobroga dupina građena je od nemijeliziranih živčanih vlakana između kojih se nalaze brojni pituiciti
