CHICK GONADOGENESIS FOLLOWING EARLY SURGICAL BURSECTOMY .1. HISTOLOGICAL, MORPHOMETRIC AND HISTOCHEMICAL DATA ON THE EMBRYONIC LEFT OVARY

Left ovaries of bursectomized chick embryos were examined on the 17th day of incubation in comparison to normal and sham-operated controls, by histological and histochemical observations. The results show that in bursectomized embryos the cortex appears irregulary developed, with a significant decrease in the mean thickness and in the percentage of the secondary sex cords in the total cortical area. Furthermore, the germinal epithelium appears thicker and the subcortical medulla and th e tunica albuginea more compact. The greater activity of the enzyme DE LTA5-3beta-hydroxysteroid dehydrogenase (DELTA3betaHSD) found in ovari es of bursectomized embryos (histochemical method) could be related to an endocrine dismetabolism affecting the cortical development. On the basis of these results and those of other authors, some hypotheses ar e advanced. In particular, an action of the bursal factor on GTH recep tors could be the factor responsible of the enhanced steroidogenic act ivity altering the hormonal environment.