Vascular reactivity to methoxamine in conscious sinoaortic denervated rats.
Alterations in vascular alpha-adrenoceptor responsiveness following sinoaortic denervation was studied in conscious rats. The arterial hypertension observed in baroreceptor denervated rats decreased progressively during the 30 days of observation. A pressor hyperresponsiveness to methoxamine (10-80 micrograms/kg, iv), was observed 3 to 7 days after baroreceptor denervation followed by a gradual normalization of the vascular reactivity. The results indicate a possible participation of an enhanced alpha 1-adrenoceptor-mediated vasoconstrictor component in the early phase of neurogenic hypertension.
Moysés
M R
MR
Departamento de Ciencias Fisiológicas, Universidade Federal do Esprito Santo, Vitória, ES, Brasil.
Cabral
A M
AM
Vasquez
E C
EC
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D003714:Denervation; D006339:Heart Rate / Q000187:drug effects*; D008297:Male; D008729:Methoxamine / Q000494:pharmacology*; D010656:Phenylephrine / Q000494:pharmacology; D011311:Pressoreceptors / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000502:physiology; D012016:Reference Values; D012849:Sinoatrial Node / Q000502:physiology*
D011942:Receptors, Adrenergic, alpha; D010656:Phenylephrine; D008729:Methoxamine