scholarly journals The relation between calcium ion transport and adenylate cyclase activity in myocardial sarcoplasmic-reticulum preparations

1972 ◽  
Vol 128 (3) ◽  
pp. 109P-109P ◽  
Author(s):  
I M Gillibrand ◽  
P A Miall
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Adenylate Cyclase ◽  
Ion Transport ◽  
Calcium Ion ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Calcium Ion Transport

scholarly journals Differential effects of non-ionic detergents on microsomal and sarcolemmal adenylate cyclase in cardiac muscle

1978 ◽  
Vol 175 (1) ◽  
pp. 171-180 ◽  
Author(s):  
Prakash V. Sulakhe ◽  
Njanoor Narayanan
Keyword(s):  
Enzyme Activity ◽  
Sarcoplasmic Reticulum ◽  
Adenylate Cyclase ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Protein Ratio ◽  
Guinea Pig Heart ◽  
Cardiac Sarcoplasmic Reticulum ◽  
Ionic Detergent ◽  
Triton X

1. About 4 and 23% of the homogenate adenylate cyclase activity was recovered in the microsomal and sarcolemmal fractions isolated from guinea-pig heart ventricles. 2. Cardiac microsomal adenylate cyclase activity [basal as well as p[NH]ppG (guanyl-5′-yl imidodiphosphate)- and NaF-stimulated] was increased over 2-fold in the presence of Lubrol-PX (0.01–0.1%). 3. The sarcolemmal enzyme, however, showed concentration-dependent inhibition caused by the detergent under all assay conditions, except when p[NH]ppG was included in the assay. In the latter case, the detergent (0.01–0.02%) caused a modest increase (30–45%) in enzyme activity. 4. Another non-ionic detergent, Triton X-100, also stimulated the microsomal cyclase and inhibited the sarcolemmal enzyme. 5. With either membrane fraction, Lubrol-PX solubilized the enzyme when the detergent/membrane protein ratio was 2.5 (μmol of detergent/mg of protein). 6. The findings with homogenate and a washed particulate fraction resembled those obtained with sarcolemma, and those with isolated sarcoplasmic reticulum resembled those with microsomal preparations. 7. p[NH]ppG, and to some extent NaF, protected the detergent-induced inactivation of the enzyme observed at higher detergent concentrations (0.5% Lubrol-PX and 0.05–0.5% Triton X-100). 8. In the absence of detergents, p[NH]ppG increased the basal enzyme activity about 2-fold in microsomal fractions, but did not appreciably stimulate the sarcolemmal enzyme. Isoproterenol, on the other hand, increased the sarcolemmal enzyme activity (>2-fold) in the presence of p[NH]ppG and caused only moderate stimulation (31%) of the microsomal enzyme under these conditions. 9. These findings support the view that, although the bulk of adenylate cyclase resides in heart sarcolemma (plasma membrane), the microsomal activity cannot be accounted for solely by contamination of the microsomal fraction with sarcolemma, as has been suggested by others [Besch, Jones & Watanabe (1976) Circ. Res.39, 586–595; Engelhard, Plut & Storm (1976) Biochim. Biophys. Acta451, 48–61]. Further, the results of this study show that cardiac sarcoplasmic-reticulum membranes possess this enzyme.

scholarly journals Calcium ion: A modulator of parotid adenylate cyclase activity

FEBS Letters ◽  
1974 ◽  
Vol 42 (3) ◽  
pp. 267-270 ◽  
Author(s):  
Douglas J. Franks ◽  
Lee S. Perrin ◽  
Daniel Malamud
Keyword(s):  
Adenylate Cyclase ◽  
Calcium Ion ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity

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).

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