Effects of Glucocorticoid Deficiency on Renal Medullary Cyclic Adenosine Monophosphate of Rats

1978 ◽  
Vol 54 (5) ◽  
pp. 573-577 ◽  
Author(s):  
K. Kurokawa ◽  
E. Aznar ◽  
C. Descoeudres ◽  
Anicia Zulueta ◽  
S. G. Massry
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Antidiuretic Hormone ◽  
Adenosine Monophosphate ◽  
Water Diuresis ◽  
Glucocorticoid Deficiency ◽  
Impaired Water ◽  
Adrenalectomized Rats

1. The effects of adrenalectomy on the adenylate cyclase—adenosine 3′:5′-cyclic monophosphate (cyclic AMP) system of rat renal medulla were examined to evaluate the mechanism of the impaired water diuresis in glucocorticoid deficiency. 2. Concentrations of cyclic AMP in medullary tubules from adrenalectomized rats were significantly higher than in the tubules from control animals both in the presence and absence of antidiuretic hormone. 3. This abnormality was corrected by the treatment in vivo of the adrenalectomized rats with dexamethasone, but addition of this drug to the incubation medium did not abolish the differences in cyclic AMP between tubules from adrenalectomized and normal rats. 4. The activity of adenylate cyclase or cyclic AMP phosphodiesterase in vitro was not affected by adrenalectomy. 5. In glucocorticoid deficiency, the concentration of cyclic AMP in medullary tubules is increased both with and without antidiuretic hormone. This abnormality may render medullary tubules more permeable to water and may underlie the impaired water diuresis in glucocorticoid deficiency.

Cannabinoid effects on adenylate cyclase and phosphodiesterase activities of mouse brain

1977 ◽  
Vol 55 (4) ◽  
pp. 934-942 ◽  
Author(s):  
Thomas W. Dolby ◽  
Lewis J. Kleinsmith
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Mouse Brain ◽  
Biogenic Amine ◽  
Specific Activity ◽  
Intraperitoneal Administration ◽  
The Brain

The experiments presented in this paper examine the mechanisms underlying the ability of cannabinoids to alter the in vivo levels of cyclic adenosine 3′,5′-monophosphate (cyclic AMP) in mouse brain. It was found that changes in cyclic AMP levels are a composite result of direct actions of cannabinoids on adenylate cyclase (EC 4.6.1.1) activity and indirect actions involving the potentiation or inhibition of biogenic amine induced activity of adenylate cyclase. Furthermore, the long-term intraperitoneal administration of 1-(−)-Δ-tetrahydrocannabinol to mice produced a form of phosphodiesterase (EC 3.1.4.17) in the brain whose activity is not stimulated by Ca2+, although its basal specific activity is similar to that of control animals. In vitro, the presence of the cannabinoids caused no significant changes in activity of brain PDE at the concentrations tested. Some correlations are presented which imply that many of the observed behavioral and physiological actions of the cannabinoids in mammalian organisms may be mediated via cyclic AMP mechanisms.

Renal cyclic AMP accumulation and adenulate cyclase stimulation by erythropoietic agents

1975 ◽  
Vol 229 (5) ◽  
pp. 1387-1392 ◽  
Author(s):  
GM Rodgers ◽  
JW Fisher ◽  
WJ George
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Regional Distribution ◽  
Renal Medulla ◽  
Iron Incorporation ◽  
Erythropoietin Production ◽  
Cyclic Amp Accumulation ◽  
Stimulation Of

The regional distribution of cyclic AMP in the kidney was determined following erythropoietic stimulation with hypoxia and cobalt. Following these stimuli, increases in renal cyclic AMP concentrations were restricted to the cortex. The basis for this localization in the case of cobalt treatment was found to reside in the stimulation of renal cortical adenylate cyclase activity in vitro by concentrations of cobalt similar to those found in vivo. The level of cobalt in the cortex after cobalt treatment was found to approach 500 mumol/kg of tissue, whereas no detectable levels of cobalt were found in the renal medulla. Additionally, other agents such as parathyroid hormone and lactic acid, that are known to lack stimulatory effects on medullary adenylate cyclase, were found to stimulate the cortical enzyme. This stimulation of renal cortical adenylate cyclase correlates with enhanced erythropoiesis as demonstrated by increased radiolabeled iron incorporation into erythrocytes. These results support previous reports which suggest that renal cortical cyclic AMP mediates erythropoietin production in response to erythropoietically active agents.

EFFECT OF HUMAN CHORIONIC GONADOTROPHIN ON ADENYLATE CYCLASE ACTIVITY AND TESTOSTERONE CONTENT IN RAT TESTICULAR MITOCHONDRIA

1977 ◽  
Vol 75 (1) ◽  
pp. 119-126 ◽  
Author(s):  
SOREL SULIMOVICI ◽  
M. S. ROGINSKY
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Dibutyryl Cyclic Amp ◽  
Trophic Hormone

The adenylate cyclase activity and the concentration of testosterone in testicular mitochondria from immature rats were measured after administration of human chorionic gonadotrophin (HCG) or dibutyryl cyclic AMP in vivo or in vitro. Intratesticular injection of HCG produced an increase in adenylate cyclase activity which preceded the rise in the level of testosterone, whereas addition of the trophic hormone in vitro resulted in simultaneous increases. Administration of dibutyryl cyclic AMP in vivo enhanced the testosterone content of the mitochondria. However, the cyclic nucleotide added in vitro at concentrations up to 5 mmol/l had no effect. Cycloheximide injected intraperitoneally before the administration of HCG abolished the stimulatory effect of the trophic hormone on the level of testosterone in the mitochondria, whereas chloramphenicol had no effect. These results, although they confirm the role of cyclic AMP as an intermediate in the stimulatory effect of HCG on the concentration of testosterone in rat testis, do not support a role for mitochondrial adenylate cyclase in this action. A protein regulator(s) formed extramitochondrially appears to be involved in the stimulatory effect of gonadotrophins on steroidogenesis.

Origin of Cyclic Adenosine Monophosphate in Saliva

1975 ◽  
Vol 54 (3) ◽  
pp. 535-539 ◽  
Author(s):  
Takao Kanamori ◽  
Toshiharu Nagatsu ◽  
Shosei Matsumoto
Keyword(s):  
Salivary Gland ◽  
Cyclic Amp ◽  
Submandibular Gland ◽  
Submaxillary Gland ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate

The level of cyclic adenosine monophosphate (AMP) in duct saliva from the dog submandibular gland was increased after cyclic AMP was administered intravenously in vivo. Isoproterenol increased the level of cyclic AMP in plasma and saliva in vivo and in salivary gland slices in vitro, but increased the level only slightly in saliva in a perfused dog submaxillary gland.

Short-term effect of aldosterone on vasopressin-sensitive adenylate cyclase in rat collecting tubule

1993 ◽  
Vol 264 (5) ◽  
pp. F821-F826 ◽  
Author(s):  
G. el Mernissi ◽  
C. Barlet-Bas ◽  
C. Khadouri ◽  
L. Cheval ◽  
S. Marsy ◽  
...  
Keyword(s):  
Adenylate Cyclase ◽  
Affinity Constant ◽  
Short Term ◽  
Collecting Tubule ◽  
Lag Period ◽  
In Vitro Effects ◽  
Collecting Tubules ◽  
Adrenalectomized Rats

Because previous studies indicated that, in the rat collecting tubule, vasopressin (AVP)-sensitive adenylate cyclase (AC) is controlled by mineralocorticoids in the long term, the present study was designed to investigate whether such a control also exists in the short term. Therefore, we investigated the in vivo and in vitro effects of aldosterone on AC activity in cortical and outer medullary collecting tubules (CCD and OMCD, respectively) from adrenalectomized rats. Injection of aldosterone (10 micrograms/kg body wt) to adrenalectomized rats restored within 3 h AVP-sensitive AC activity in the CCD and OMCD up to the levels observed in the corresponding segments of adrenal intact rats. Similarly, incubating CCD or OMCD from adrenalectomized rats for 2.5 h in the presence of 10(-8) M aldosterone enhanced AVP-sensitive AC activity up to values similar to those found in normal rats. In vitro stimulation of AVP-sensitive AC activity was dose dependent with regard to aldosterone [apparent affinity constant (K0.5) approximately 10(-9) M], appeared after a 30-min lag period, and reached its maximum after 2-2.5 h. In addition, it was totally abolished by the antimineralocorticoid spironolactone, whereas the specific glucocorticoid antagonist RU 38486 had no effect. Finally, actinomycin D and cycloheximide totally abolished the in vitro action of aldosterone, demonstrating the involvement of protein synthesis in that process.

scholarly journals Dictyostelium discoideum mutant synag 7 with altered G-protein-adenylate cyclase interaction

1988 ◽  
Vol 91 (2) ◽  
pp. 287-294
Author(s):  
B.E. Snaar-Jagalska ◽  
P.J. Van Haastert
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
G Protein ◽  
Dictyostelium Discoideum ◽  
High Speed ◽  
Wild Type ◽  
High Affinity ◽  
Gtp Binding

Previous results have shown that Dictyostelium discoideum mutant synag 7 is defective in the regulation of adenylate cyclase by receptor agonists in vivo and by GTP gamma S in vitro; the guanine nucleotide activation of adenylate cyclase is restored by the high-speed supernatant from wild-type cells. Here we report that in synag 7 membranes: (1) cyclic AMP receptors had normal levels and were regulated by guanine nucleotides as in wild-type; (2) GTP binding and high-affinity GTPase were reduced but still stimulated by cyclic AMP; (3) the supernatant from wild-type cells restored GTP binding to membranes of this mutant, and partly restored high-affinity GTPase activity; (4) the supernatant of synag 7 was ineffective in these reconstitutions and did not influence GTP binding and GTPase activities in mutant or wild-type membranes. These results suggest that the defect in mutant synag 7 is located between G-protein and adenylate cyclase, and not between receptor and G-protein. A factor in the supernatant is absent in synag 7 and appears to be essential for normal GTP binding, GTPase and activation of adenylate cyclase. This soluble heat-labile factor may represent a new molecule required for receptor- and G-protein-mediated activation of adenylate cyclase.

Cytochemical Evidence for Presynatic β-Adrenergic Regulation of Secretion in the Developing Rat Submandibular Gland

1977 ◽  
Vol 35 ◽  
pp. 430-431
Author(s):  
L.S. Cutler
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Submandibular Gland ◽  
Neonatal Rat ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Parotid Glands ◽  
Adrenergic Agonist ◽  
Rat Submandibular Gland

Many studies previously have shown that the B-adrenergic agonist isoproterenol and the a-adrenergic agonist norepinephrine will stimulate secretion by the adult rat submandibular (SMG) and parotid glands. Recent data from several laboratories indicates that adrenergic agonists bind to specific receptors on the secretory cell surface and stimulate membrane associated adenylate cyclase activity which generates cyclic AMP. The production of cyclic AMP apparently initiates a cascade of events which culminates in exocytosis. During recent studies in our laboratory it was observed that the adenylate cyclase activity in plasma membrane fractions derived from the prenatal and early neonatal rat submandibular gland was retractile to stimulation by isoproterenol but was stimulated by norepinephrine. In addition, in vitro secretion studies indicated that these prenatal and neonatal glands would not secrete peroxidase in response to isoproterenol but would secrete in response to norepinephrine. In contrast to these in vitro observations, it has been shown that the injection of isoproterenol into the living newborn rat results in secretion of peroxidase by the SMG (1).

Epinephrine Induces von Willebrand Factor Release from Cultured Endothelial Cells: Involvement of Cyclic AMP-dependent Signalling in Exocytosis

1997 ◽  
Vol 77 (06) ◽  
pp. 1182-1188 ◽  
Author(s):  
Ulrich M Vischer ◽  
Claes B Wollheinn
Keyword(s):  
Endothelial Cells ◽  
Adenylate Cyclase ◽  
Von Willebrand Factor ◽  
Umbilical Vein ◽  
Free Calcium ◽  
Camp Content ◽  
Von Willebrand ◽  
Willebrand Factor

Summaryvon Willebrand factor (vWf) is released from endothelial cell storage granules after stimulation with thrombin, histamine and several other agents that induce an increase in cytosolic free calcium ([Ca2+]i). In vivo, epinephrine and the vasopressin analog DDAVP increase vWf plasma levels, although they are thought not to induce vWf release from endothelial cells in vitro. Since these agents act via a cAMP-dependent pathway in responsive cells, we examined the role of cAMP in vWf secretion from cultured human umbilical vein endothelial cells. vWf release increased by 50% in response to forskolin, which activates adenylate cyclase. The response to forskolin was much stronger when cAMP degradation was blocked with IBMX, an inhibitor of phosphodiesterases (+200%), whereas IBMX alone had no effect. vWf release could also be induced by the cAMP analogs dibutyryl-cAMP (+40%) and 8-bromo-cAMP (+25%); although their effect was weak, they clearly potentiated the response to thrombin. Epinephrine (together with IBMX) caused a small, dose-dependent increase in vWf release, maximal at 10-6 M (+50%), and also potentiated the response to thrombin. This effect is mediated by adenylate cyclase-coupled β-adrenergic receptors, since it is inhibited by propranolol and mimicked by isoproterenol. In contrast to thrombin, neither forskolin nor epinephrine caused an increase in [Ca2+]j as measured by fura-2 fluorescence. In addition, the effects of forskolin and thrombin were additive, suggesting that they act through distinct signaling pathways. We found a close correlation between cellular cAMP content and vWf release after stimulation with epinephrine and forskolin. These results demonstrate that cAMP-dependent signaling events are involved in the control of exocytosis from endothelial cells (an effect not mediated by an increase in [Ca2+]i) and provide an explanation for epinephrine-induced vWf release.

scholarly journals Interactions between adenylate cyclase and the yeast GTPase-activating protein IRA1.

1991 ◽  
Vol 11 (9) ◽  
pp. 4591-4598 ◽  
Author(s):  
M R Mitts ◽  
J Bradshaw-Rouse ◽  
W Heideman
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Adenylate Cyclase System ◽  
Gtpase Activating Protein ◽  
Yeast Saccharomyces Cerevisiae ◽  
Strong Candidate ◽  
Sepharose 4B ◽  
Stimulation Of ◽  
Cyclic Amp Synthesis

The adenylate cyclase system of the yeast Saccharomyces cerevisiae contains many proteins, including the CYR1 polypeptide, which is responsible for catalyzing the formation of cyclic AMP from ATP, RAS1 and RAS2 polypeptides, which mediate stimulation of cyclic AMP synthesis by guanine nucleotides, and the yeast GTPase-activating protein analog IRA1. We have previously reported that adenylate cyclase is only peripherally bound to the yeast membrane. We have concluded that IRA1 is a strong candidate for a protein involved in anchoring adenylate cyclase to the membrane. We base this conclusion on the following criteria: (i) a disruption of the IRA1 gene produced a mutant with very low membrane-associated levels of adenylate cyclase activity, (ii) membranes made from these mutants were incapable of binding adenylate cyclase in vitro, (iii) IRA1 antibodies inhibit binding of adenylate cyclase to the membrane, and (iv) IRA1 and adenylate cyclase comigrate on Sepharose 4B.

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