Postnatal development of adenylate cyclase in rat salivary glands: patterns of hormonal sensitivity

1975 ◽  
Vol 228 (2) ◽  
pp. 608-612 ◽  
Author(s):  
RJ Grand ◽  
DA Chong ◽  
SJ Ryan
Keyword(s):  
Adenylate Cyclase ◽  
Parotid Gland ◽  
Salivary Glands ◽  
Postnatal Development ◽  
Submandibular Gland ◽  
Developmental Change ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Postnatal Life ◽  
Membrane Function

In order to compare the known morphological changes which occur during the postnatal development of the salivary glands in the rat with alterations in membrane function, we measured adenylate cyclase activity and its responses to sodium fluoride (NaF), norepinephrine, and isoproterenol in salivary gland membranes at various times after birth. In the parotid gland, basal enzyme activity did not change significantly during postnatal life, but fluoride-stimulated activity rose on day 15; A similar marked rise in activity stimulated by norepinephrine (0.02 mM) and isoproterenol (0.03 mM) was noted simultaneously. In the submandibular gland, basal adenylate cyclase activity was higher just after birth than at 25 days of life or in maturity. Fluoride-stimulated activity was 7 times higher than basal activity on day 1, greater than 10 times higher on day 25, and 30 times greater in the adult. The gland was as responsive to norepinephrine and isoproterenol on day 5 as it was on day 25 or in the mature animal, showing a two- to threefold increase over the basal enzyme value at each time point studied. Residual phosphodiesterase activity in the membranes was always negligible. The data demonstrate a time-dependent developmental change in the responsiveness of the parotid gland to norepinephrine and isoproterenol, which corresponds to the time when morphological maturation normally occurs. By contrast, in the submandibular gland, membrane-bound adenylate cyclase is fully developed at the time of birth.

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).

Calmodulin activation and calcium regulation of parotid gland adenylate cyclase

1986 ◽  
Vol 250 (4) ◽  
pp. C642-C645 ◽  
Author(s):  
M. T. Piascik ◽  
M. Babich ◽  
K. L. Jacobson ◽  
E. L. Watson
Keyword(s):  
Adenylate Cyclase ◽  
Parotid Gland ◽  
Calcium Regulation ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Amylase Secretion ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Maximal Stimulation ◽  
Maximal Activation

The effect of Ca2+ on the adenylate cyclase activity associated with membranes prepared from mouse parotid gland has been examined. Ca2+ stimulated then inhibited adenylate cyclase activity, with values for half-maximal stimulation and inhibition of 0.6 and 10 microM, respectively. Maximal activation (1.4-fold) was observed at 2 microM free Ca2+. These membranes contained 1.2 microgram calmodulin/mg protein. Exogenous calmodulin (0.2-1.2 microgram) activated, in a concentration-dependent manner, adenylate cyclase activity, with maximal activation being 2.5-fold at 12 micrograms calmodulin. Preparation of membranes in 2 mM ethyleneglycol-bis(beta-aminoethylether)-N,N,N',N'-tetraacet ic acid (EGTA) resulted not only in a significant decrease in calmodulin levels (0.5 microgram calmodulin/mg protein) but also in a loss of the ability of Ca2+ to stimulate the enzyme. Exogenous calmodulin restored the ability of Ca2+ to stimulate the adenylate cyclase activity associated with EGTA-treated membranes. Trifluoperazine (50 microM) blocked the ability of Ca2+ to activate adenylate cyclase activity in control membranes. The effect of trifluoperazine could be reversed by exogenous calmodulin (0.5 or 5.0 micrograms). These data indicate that calmodulin mediates the activation of parotid gland adenylate cyclase by Ca2+ and that Ca2+, at concentrations which stimulate and inhibit amylase secretion, can activate and inhibit adenylate cyclase activity.

Biochemical and cytochemical studies on adenylate cyclase activity in the developing rat submandibular gland: differentiation of the acinar secretory compartment

Development ◽  
1976 ◽  
Vol 36 (2) ◽  
pp. 291-303
Author(s):  
Leslie S. Cutler ◽  
Sevgi B. Rodan
Keyword(s):  
Adenylate Cyclase ◽  
Submandibular Gland ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Apical Plasma Membrane ◽  
Secretory Cells ◽  
Cytochemical Localization ◽  
Membrane Changes ◽  
Rat Submandibular Gland ◽  
Developing Rat

To investigate membrane changes in development of the exocrine cells of the rat submandibular gland (SMG), biochemical and cytochemical studies of adenylate cyclase activity were performed on prenatal and postnatal glands. SMG rudiments and glands were studied from 15 days of gestation up to birth and 1, 2, 3, 4 and 24 weeks after birth. Glands were chemically assayed for adenylate cyclase activity using the procedures of Salomon and coworkers and cytochemically studied using a procedure which was verified biochemically. At 15–16 days of gestation basal adenylate cyclase activity was low and no staining could be observed. Adenylate cyclase activity rose six-fold from the 16th to the 18th day of gestation. Adenylate cyclase staining became evident along the surface of most of the cells of the rudiment at this time. Basal adenylate cyclase activity remained relatively constant from the 18th day of gestation up to 24 weeks of age. However, sequential changes were seen in the cytochemical localization, especially in relation to the apical plasma membrane of the developing secretory cells.

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