Studies on Cyclic Nucleotides in the Adrenal Gland

Abstract

Abstract-Studieson the zonal function of CAMP-binding protein (regulatory pro tein) and CAMP-dependent protein kinases in bovine adrenal glands have been made. Partially purified CAMP-binding protein from bovine adrenal gland divided into three zones, the capsular (zona glomerulosa), the decapsulated (zona fasciculata and reticularis) and the medulla gland was found in microsomal and cytosol fractions.

Studies on Cyclic Nucleotides in the Adrenal Gland VII. Cyclic AMP Systems in the Adrenal Medulla in Vivo

“…2). This supports the results obtained in previous experiments in vitro on the bovine adrenal medulla (7)(8)(9). There was no increase in cyclic AMP levels in the adrenal venous effluent, suggesting that this increase in the adrenal medulla is confined within the tissue.…”

“…The remaining plasma and the medullary portion of adrenal glands were used for determination of cyclic AMP levels based on the method of Gilman (16). Estimation of the adenylate cyclase activity was performed as previously described (8). Medullary portions were homogenized in 10 vol of ice-cold 10 mM Tris-HC1 buffer (pH 7.4) containing 0.25 M sucrose, 2 mM glycylglycine, 6 mM mercaptoethanol, 1 mM EDTA, and 2 mM MgCl2 in a Potter-Elvehjem homogenizer with a close fitting teflon pestle.…”

“…Recent reports (1)(2)(3)(4)(5)(6) have stated that trans-synaptic activation in vivo induced an increase in cyclic AMP accumulation, followed by subsequent events including activation of protein kinase and induction of tyrosine 3-monooxygenase in the rat adrenal medulla. Previous studies (7)(8)(9) in vitro showed that incubation of slices from bovine adrenal medulla with acetylcholine increased tissue levels of cyclic AMP some time after stimulation of the cate cholamine-release. It was of interest that a renewal of the incubation medium produced a greater increase in cyclic AMP levels after the acetylcholine-stimulation (9).…”

“…Since the experiment using adrenal medulla slices is not an ideal system (8,10) the method referred to `the retrograde-adrenal vein infusion' (11)(12) and `the intra-adrenal infusion' (13)(14), in which an unilateral adrenal of the rat is exposed directly to the drugs and the release of hormones and cyclic nucleotides in the adrenal venous effluent is estimated in situ , was employed in the present studies. Experiments in vivo reported hitherto demonstrated the difficulty in eliminating the systemic factors on the gland which had been indirectly influenced by the method of systemic administration of the drugs (1-2).…”

Studies on Cyclic Nucleotides in the Adrenal Gland V. Adenylate Cyclase in the Adrenal Medulla

“…Moreover, the higher activity of cyclic AMP-dependent pro tein kinase from the cortex than that of the medullary enzyme was attributed to difference in the cyclic AMP-binding activity of the regulatory proteins associated with the enzymes (3)(4).…”