RT info:eu-repo/semantics/article
T1 Effect of phenylephrine and prazosin on the somatostatinergic system in the rat frontoparietal cortex
A1 López Sañudo, Susana
A1 Rodríguez Martín, Eulalia
A1 Martín Espinosa, Ángela
A1 Arilla Ferreiro, Eduardo
K1 Phenylephrine
K1 Prazosin
K1 Somatostatin receptors
K1 Adenylate cyclase
K1 G-proteins
K1 Frontoparietal cortex
K1 Bioquímica
K1 Biochemistry
K1 Science
K1 Ciencia
AB Somatostatin (SS) and noradrenaline (NA) are distributed in the rat cerebral cortex, and seizure activity is one of the aspects of behavior affected by both neurotransmitters. Due to the possible interaction between both neurotransmitter systems, we studied whether phenylphrine, an alpha(1)-adrenoceptor agonist, and prazosin, an alpha(1)-adrenoceptor antagonist, can modulate SS-like immunoreactivity (SS-LI) levels, binding of [I-125][Tyr(11)]SS to its specific receptors, the ability of SS to inhibit adenylate cyclase (AC) activity, and the guanine nucleotide binding regulatory protein G(1) and G(0), in the Sprague-Dawley rat frontoparietal cortex. An IP dose of 2 or 4 mg/kg of phenylephrine injected 7 h before decapitation decreased the number of SS receptors and increased the apparent affinity in frontoparietal cortex membranes. An IP dose of 20 or 25 mg/kg of prazosin administered 8 h before decapitation increased the number of SS receptors and decreased their apparent affinity. The administration of prazosin before the phenylephrine injection prevented the phenylephrine-induced changes in SS binding. The addition of phenylephrine and/or prazosin 10(-5) M to the incubation medium changed neither the number nor the affinity of the SS receptors in the frontoparietal cortex membranes. Phenylephrine or prazosin affected neither SS-LI content nor the basal or forskolin (FK)-stimulated AC activities in the frontoparietal cortex. In addition, SS caused an equal inhibition of AC activity in frontoparietal cortex membranes of phenylephrine- and prazosin-treated rats compared with the respective control group. Finally, phenylephrine and prazosin did not vary the pertussis toxin (PTX)-catalyzed ADP ribosylation of G(1)- and/or G(0)-proteins. These results suggest that the above mentioned changes are related to the phenylephrine activation of alpha(1)-adrenoceptors or to the blocking of these receptors by prazosin. In addition, these data provide further support for a functional interrelationship between the alpha(1)-adrenergic and somatostatinergic systems in the rat frontoparietal cortex.
PB Elsevier
SN 0196-9781
YR 1994
FD 1994
LK http://hdl.handle.net/10017/2316
UL http://hdl.handle.net/10017/2316
LA eng
NO Ministerio de Educación y Ciencia
DS MINDS@UW
RD 20-abr-2024