Fine structure of the rostral pars distalis follicle cells in homotransplanted pituitaries of rainbow trout, Salmo gairdneri.

Abstract

Pituitary glands from 'donor' rainbow trout were transplanted into the anterior eye compartment of 'recipient' fish to examine the nature of hypothalamic control of the follicle cells in salmonid fishes and to explore the possibility of using the eye as a site of pituitary implantation that permits successful recovery of the grafted gland. After 7 weeks the transplanted prolactin cells appeared less active than in in situ glands and some of the follicle cells appeared to be undergoing degenerative processes. This inhibition of prolactin cell activity was thought to be due to the higher osmotic pressure of the ocular fluid.The follicular formation of the prolactin and non-granulated cells was retained in transplanted glands, although the follicle lumina were smaller than in in situ glands and commonly contained cellular debris. This may suggest that the lumina are sites of cellular degradation and possibly stores of precursor substances.