Effect of castration and adrenalectomy on the ultrastructure of pinealocytes in the female garden dormouse (Eliomys quericnus L.) under different conditions of lighting and temperature during the normal period of hibernation.

The ultrastructure of the female garden dormouse pinealocyte has been studied during the period of hibernation in normal, castrated, castrated and adrenalectomized hibernant animals and non-hibernant ones living under a L-D = 10-14 photoperiodicity or continuous lighting. Continuous illumination on the one hand, and gonad and adrenalectomy on the other, have similar effects on the ultrastructure of pinealocytes. Especially a striking reduction of liposomes, an increased development of the Golgi apparatus and of cisterns formed by the rough endoplasmic reticulum were observed. The observations suggest that the liposomes are involved in a perhaps indoleaminergic antigonadotropic secretory process whereas the peculiar dilated cisterns of the rough endoplasmic reticulum may be related with a pineal polypeptidergic gonadotropic secretory process.