MORPHOLOGICAL ASSESSMENT IN PINEALECTOMY AND FETAL PINEAL-GLAND TRANSPLANTATION IN RATS .1.

The effects of pineal gland, an endocrine organ known to affect the ph ysiology of various organs and systems including the hypothalamo-hypop hyseal axis, on the morphological characteristics of target organs wer e investigated in rats after pinealectomy and foetal pineal gland tran splantation to a subpial cortical area close to the pinealectomized re gion. It was demonstrated that weight gain was significantly slower in pinealectomized male rats (p < 0.01); pituitary gland weight was lowe r in the pinealectomized group (p < 0.01) and transplantation had no e ffect on the weight of this organ; weight of adrenal gland and testis were lower after pinealectomy (p < 0.01) but restored back to control levels after transplantation; the mitotic activity in seminiferous tub ules increased with pinealectomy and returned back to control indexes after transplantation. Research on hypothalamic catecholaminergic cont ent revealed a diminished histofluorescence in pinealectomized rats wh ich showed a potentiated restoration after transplantation. The innerv ation of the pineal gland was studied by anterograde and retrograde in jections of Wheat Germ Agglutinin Horse Radish Peroxidase from superio r cervical ganglion and pineal gland, respectively. It was demonstrate d that cell bodies were traced both at the transplanted tissue and hyp othalamus. In view of these data, the multifunctional and a probable h igh level homeostatic harmony regulator essence of pineal gland is dis cussed.