Calcium ion: A modulator of parotid adenylate cyclase activity

Franks, Douglas J.; Perrin, L.; Malamud, Daniel

doi:10.1016/0014-5793(74)80742-8

Cited by 19 publications

(2 citation statements)

References 15 publications

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“…The non-hydrolyzable GTP analog Gpp(NH)p (tested at the same concentration) and 10 mM fluoride stimulated the enzyme 10-fold. CaCl2 exerted an inhibitory effect when tested at a 0.3 mM concentration, in the présence of 100 ^M GTP: the enzymatic activity was decreased 2.5-fold, a resuit in contradiction with that of Franks et al [10] who reported a stimulatory effect of Ca^* when tested at the same concentration but this observation was made in the absence of GTP. The integrity of ^-adrenergic receptors was obvious since 1 isoproterenol stimulated the activity 6-fold, in the présence of 100 GTP.…”

Section: General Responsiveness Of Rat Parotid Membranescontrasting

confidence: 69%

Adenylate cyclase stimulation by VIP in rat and human parotid membranes

Bogaert¹,

Soukias

Dehaye³

et al. 1987

Regulatory Peptides

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Adenylate cyclase activity was stimulated by vasoactive intestinal peptide (VIP) in rat parotid membranes, in the presence of 100 microM guanosine triphosphate (GTP). The threshold concentration of VIP was 300 nM and the activity doubled at the maximal VIP concentration tested (30 microM). The relative potency of peptides of the VIP family was: VIP greater than peptide histidine isoleucinamide (PHI) greater than secretin. The beta-adrenergic agent isoproterenol was a more efficient activator of rat parotid adenylate cyclase and its stimulatory effect, like that of VIP, depended on the presence of GTP. The effects of VIP and isoproterenol were both potentiated by 10 microM forskolin. By comparison with rat parotid preparations, membranes from a human parotid gland responded similarly to the VIP family of peptides (VIP greater than PHI greater than secretin). In both rat and human parotid membranes, two proteins (Mr 44 kDa and 53 kDa) of the alpha-subunit of Ns (the guanyl nucleotide-binding stimulatory protein) were labelled by ADP-ribosylation, in the presence of cholera toxin. Taken together, these results indicate that VIP receptors, when coupled to Ns, were able to activate the adenylate cyclase system in rat and human parotid membranes.

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Section: General Responsiveness Of Rat Parotid Membranescontrasting

confidence: 69%

Adenylate cyclase stimulation by VIP in rat and human parotid membranes

Bogaert¹,

Soukias

Dehaye³

et al. 1987

Regulatory Peptides

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“…The fact that the calmodulin inhibitor trifluoperazine was much less potent as an inhibitor than was EGTA could indicate that a calmodulin-dependent activation of adenylate cyclase is not the only mechanism involved. Since parotid gland adenylate cyclase is calcium-dependent (Franks et al 1974) the possibility requires further study, especially since trifluoperazine is far from selective as a calmodulin antagonist when given in concentrations that block calmodulin activity completely.…”

Section: Discussionmentioning

confidence: 99%

Calcium‐dependent enhancement by carbachol of the VIP‐induced cyclic AMP accumulation in cat submandibular gland

Enyedi

Fredholm

1984

Acta Physiologica Scandinavica

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The interaction of two coexisting transmitters in the cat submandibular gland has been elucidated by studying effects of VIP and carbachol on cyclic AMP accumulation in isolated acini from the gland. Carbachol was found to potentiate the cyclic AMP increase induced by VIP by an atropine sensitive mechanism. The effect of carbachol on cyclic AMP accumulation was abolished by including EGTA in the incubation medium as was the carbachol mediated potentiation of VIP responses. The calmodulin inhibitor trifluoperazine had a similar, but less marked effect. The effect of carbachol was mimicked by phenylephrine (30 microM) and by the calcium inophore A 23187 (3 microM), and also by ethanol in a concentration reported to enhance membrane fluidity. The phospholipase A2 inhibitor, mepacrine, tended to decrease carbachol actions. Our results show that the potentiation of VIP responses in feline submandibular gland is calcium-dependent. The mechanism could involve a calcium-calmodulin-induced stimulation of adenylate cyclase or calcium-induced change in membrane phospholipid metabolism.

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Daly¹

1975

Synaptic Modulators

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Calcium ion: A modulator of parotid adenylate cyclase activity

Cited by 19 publications

References 15 publications

Adenylate cyclase stimulation by VIP in rat and human parotid membranes

Adenylate cyclase stimulation by VIP in rat and human parotid membranes

Calcium‐dependent enhancement by carbachol of the VIP‐induced cyclic AMP accumulation in cat submandibular gland

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