Oxygen consumption in the rectal gland of the dogfishScyliorhinus canicula and the effects of cyclic AMP

1980 ◽  
Vol 136 (1) ◽  
pp. 39-43 ◽  
Author(s):  
T. J. Shuttleworth ◽  
J. L. Thompson
Keyword(s):  
Oxygen Consumption ◽  
Cyclic Amp ◽  
Rectal Gland

Cyclic AMP stimulates ouabain-insensitive ion movement in shark rectal gland

1984 ◽  
Vol 154 (2) ◽  
pp. 139-144 ◽  
Author(s):  
Patricio Silva ◽  
Kate Spokes ◽  
Jonathan A. Epstein ◽  
Arthur Stevens ◽  
Franklin H. Epstein
Keyword(s):  
Cyclic Amp ◽  
Rectal Gland ◽  
Ion Movement ◽  
Shark Rectal Gland

Role of calcium in cAMP-mediated effects in the elasmobranch rectal gland

1983 ◽  
Vol 245 (6) ◽  
pp. R894-R900
Author(s):  
T. J. Shuttleworth
Keyword(s):  
Oxygen Consumption ◽  
Secretory Activity ◽  
Rectal Gland ◽  
Ouabain Binding ◽  
Calcium Dependent ◽  
Mediated Effects ◽  
Cotransport System ◽  
Vasodilatory Action ◽  
Potent Vasoconstrictor ◽  
Stimulation Of

The effects of A23187 and verapamil on the vasomotor and secretory effects of adenosine 3',5'-cyclic monophosphate (cAMP) in the rectal gland were investigated in Scyliorhinus canicula and Squalus acanthias. A23187 was a potent vasoconstrictor in the gland and reversed the vasodilatory action of cAMP in glands constricted with norepinephrine. Verapamil, like cAMP, prevented the vasoconstriction induced in the gland by norepinephrine. A23187 had no effect on the secretory activity (measured as ouabain binding and ouabain-sensitive oxygen consumption) of the glands. Verapamil inhibited the stimulation of ouabain binding, ouabain-sensitive oxygen consumption, and sodium secretion rate induced by cAMP plus theophylline, but did not affect the stimulation of ouabain binding and ouabain-sensitive oxygen consumption induced by amphotericin B. These data indicate that it is the cAMP-induced stimulation of the sodium-chloride cotransport system that is verapamil sensitive, and it is suggested that this stimulation is a calcium-dependent process. This emphasizes the independent nature of the secretory and vasomotor effects of the nucleotide in the gland.

Cyclic AMP-dependent stimulation of Na,K-ATPase in shark rectal gland

1986 ◽  
Vol 94 (3) ◽  
pp. 205-215 ◽  
Author(s):  
D. Marver ◽  
S. Lear ◽  
L. T. Marver ◽  
P. Silva ◽  
F. H. Epstein
Keyword(s):  
Cyclic Amp ◽  
Rectal Gland ◽  
Shark Rectal Gland ◽  
Stimulation Of

scholarly journals Mechanism and control of hyperosmotic NaCl-rich secretion by the rectal gland of Squalus acanthias

1983 ◽  
Vol 106 (1) ◽  
pp. 25-41 ◽  
Author(s):  
F. H. Epstein ◽  
J. S. Stoff ◽  
P. Silva
Keyword(s):  
Cyclic Amp ◽  
Chloride Secretion ◽  
Squalus Acanthias ◽  
Rectal Gland ◽  
Energetic Efficiency ◽  
Secondary Active Transport ◽  
Transport Pathway ◽  
Rectal Glands ◽  
And Control

Secretion of chloride from blood to lumen is accomplished in the rectal gland of elasmobranchs by a process of secondary active transport involving the co-transport of Cl- with Na+ across the basolateral membranes of rectal gland cells. Energy is provided by ATP via membrane Na-K-ATPase, which establishes an electrochemical gradient favouring Na+ influx into the cell. The involvement of K+ in the co-transport mechanism, so as to provide a ratio of 1 Na+:1 K+:2 Cl- entering the cell, would increase the energetic efficiency of the process, and is consistent with the Cl/O2 ration of 27–30 observed in secreting rectal glands. Secretion is stimulated by cyclic AMP (cAMP) and by vasoactive intestinal peptide (VIP) and adenosine, which activate adenylate cyclase. Activation of the gland in vivo probably occurs via VIP-secreting nerves as well as circulating agents; it is inhibited by somatostatin. Cyclic AMP probably stimulates chloride secretion by at least three mechanisms: (1) increasing chloride conductance across the luminal cell membrane, (2) enhancing the co-transport pathway for transmembrane movements of Na+, K+ and Cl- and (3) activating Na-K-ATPase.

Cyclic AMP regulation of active chloride transport in the rectal gland of marine elasmobranchs

1977 ◽  
Vol 199 (3) ◽  
pp. 443-448 ◽  
Author(s):  
Jeffrey S. Stoff ◽  
Patricio Silva ◽  
Michael Field ◽  
John Forrest ◽  
Arthur Stevens ◽  
...  
Keyword(s):  
Cyclic Amp ◽  
Chloride Transport ◽  
Rectal Gland

The mechanism of cyclic AMP stimulation of secretion in the dogfish rectal gland

1980 ◽  
Vol 140 (3) ◽  
pp. 209-216 ◽  
Author(s):  
T. J. Shuttleworth ◽  
J. L. Thompson
Keyword(s):  
Cyclic Amp ◽  
Rectal Gland ◽  
Stimulation Of

scholarly journals Haemodynamic effects of secretory agents on the isolated elasmobranch rectal gland

1983 ◽  
Vol 103 (1) ◽  
pp. 193-204 ◽  
Author(s):  
T. J. Shuttleworth
Keyword(s):  
Cyclic Amp ◽  
Adrenergic Receptors ◽  
Rectal Gland ◽  
Secretory Cells ◽  
Vascular Effects ◽  
Alpha Adrenergic Receptors ◽  
Perfusion Flow ◽  
Flow Through ◽  
Ribose Moiety

Perfusion flow rate in the isolated elasmobranch rectal gland, perfused at in vivo pressures, was measured in Scyliorhinus canicula L. and Squalus acanthias L. Flow through the secretory parenchyma of the gland was reduced in the presence of concentrations of catecholamines in the physiological range, an effect mediated via alpha-adrenergic receptors within the gland vasculature. Flow through the non-secretory vascular shunts of the rectal gland was unaffected. The vasoconstriction induced by noradrenaline was blocked by the addition of cyclic AMP + theophylline or adenosine at concentrations known to stimulate secretion by the gland. In Squalus, a similar effect was seen with the secretagogue vasoactive intestinal peptide, but this agent had no effect in the glands of Scyliorhinus. Experiments indicate that the blockage of the noradrenaline effect by the secretory agents does not involve any stimulation of vasodilatory beta-adrenergic receptors and, furthermore, that the vasomotor effects of these agents appear to be entirely independent of their actions on the secretory cells. Evidence is presented indicating that the vasomotor action of adenosine may be mediated via receptors specific for the ribose moiety of the nucleoside (Ra receptors) activating adenylate cyclase, and that this may, in turn, explain the observed effects of the addition of exogenous cyclic AMP. The significance of the observed vascular effects in the overall control of secretion rate by the gland in vivo is discussed.

Cyclic GMP attenuates cyclic AMP-stimulate inotropy and oxygen consumption in control and hypertrophic hearts

2000 ◽  
Vol 95 (1) ◽  
pp. 28-38 ◽  
Author(s):  
Richard J. Leone, Jr. ◽  
Michaela Straznicka ◽  
Peter M. Scholz ◽  
Harvey R. Weiss
Keyword(s):  
Oxygen Consumption ◽  
Cyclic Amp ◽  
Cyclic Gmp

Cyclic AMP and ouabain-binding sites in the rectal gland of the dogfishScyliorhinus canicula

1978 ◽  
Vol 206 (2) ◽  
pp. 297-302 ◽  
Author(s):  
T. J. Shuttleworth ◽  
J. L. Thompson
Keyword(s):  
Cyclic Amp ◽  
Binding Sites ◽  
Rectal Gland ◽  
Ouabain Binding
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