M S Rodríguez-Pena

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Receptors for vasoactive intestinal peptide (VIP) in membranes from rat seminal vesicle were examined using 125I-labeled VIP as ligand. The receptor binding was rapid, reversible, saturable, specific, and dependent on temperature and membrane concentration. At 15 degrees C, the stoichiometric data suggested the presence of two classes of VIP receptors with(More)
Although there is evidence that suggests that dopamine (DA) has stimulatory effects on somatostatinergic transmission, it is unknown to date if DA increases the activity of the somatostatin (SS) receptor-effector system in the rat brain. In this study, we evaluated the effects of the administration of DA and the DA D1-like (D1, D5) receptor antagonist SCH(More)
We describe the status of vasoactive intestinal peptide (VIP) receptors in regenerating liver. VIP-stimulated adenylate cyclase activity was markedly decreased in proliferating liver 3 days after partial (70%) hepatectomy. This was associated with a reduced efficacy of VIP (53% compared with controls), with no change in the potency of the peptide (ED50 0.8(More)
The stoichiometric, pharmacological and molecular properties of vasoactive intestinal peptide (VIP) receptors have been analyzed in human liver membranes and compared in parallel with those in rat liver membranes. The binding of [125I]VIP was rapid, saturable and specific. The stoichiometric data indicated the presence of two classes of binding sites in(More)
The present report describes the status of the vasoactive intestinal peptide (VIP) receptor/effector system of signal transduction in seminal vesicle from streptozotocin (STZ)-treated rats. STZ-treatment modified the binding parameters of the high-affinity sites for VIP in seminal vesicle: 0.78 +/- 0.10 and 2.54 +/- 0.30 nM for the dissociation constant(More)
To evaluate the role of G-protein-coupled receptor kinases (GRK) in the desensitization of the histamine H(2) receptor, the H(2) receptor was transiently cotransfected with GRK2, 3, 5 or 6 in COS-7 cells and the cyclic AMP levels in response to histamine were studied. Coexpression of the H(2) receptor with GRK2 and 3 significantly decreased both the basal(More)
Vasoactive intestinal peptide (VIP) stimulated adenylyl cyclase activity in membranes from rat seminal vesicle. GTP potentiated the stimulatory effect of VIP so that it was routinely included at 10 microM. The stimulation of adenylyl cyclase by VIP was time and temperature dependent. The response was linear with time up to 15 min at 30 degrees C.(More)
Vasoactive intestinal peptide (VIP) receptors coupled to activation of adenylate cyclase have been previously identified in seminal vesicle membranes of rat. In the present study we demonstrate that the synthetic peptides [4-Cl-D-Phe6,Leu17]VIP and the growth hormone releasing factor (GRF) analog [Ac-Tyr1,D-Phe2]GRF1-29-NH2 inhibit in a competitive manner(More)
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