Fine structure of the parathyroid glands of golden hamsters injected inorganic salts (CaCl_2, Mg@5o_4, Na_2HPO_4) and adrenergic agents (isoproterenol, propranolol, adrenalin, noradrenalin) under 5 gravity environment was studied (Ca, Mg, P, IP, Pro, A, Na, Ca・ 5G, Mg・ 5G, P・ 5G, IP・ 5G, Pro・ 5G, A・ 5G, and NA・ 5G groups). Immunocytochemical localization of parathyroid hormone (PTH) in the chief cells was examined. Vascular casts of the parathyroid glands were studied in the golden hamsters of control, 5G, A, A・ 5G, NA and NA ・ 5G groups by scaning electron microscopy.
Protein A-gold particles were observed on secretory granules, large secretory granules and Golgi vacuoles showing PTH positive nature. The Golgi complexes and cisternae of the granular endoplasmic reticulum were significantly increased in the P, P・ 5G, Mg・ 5G, IP, IP・ 5G, A, A・ 5G, NA and NA・5G groups and decreased in the Ca, Ca・ 5G and Pro groups as compared with those of control animals. There were no significant differences between the control and A- or NA-treated animals with regard to the vascular architecture. Accordingly, hyperactivity of the parathyroid gland in A, A ・ 5G, NA and NA・ 5G groups may reflect direct effects of A and NA to the parathyroid chief cells. Under hypergravity environment, supresseion of the parathyroid function with Pro may be relieved and stimulation with IP, A and NA may be increased.