The bed nucleus of the stria terminalis modulates baroreflex in rats.
In the present study, we report the effect of bed nucleus of stria terminalis (bed nucleus) ablation caused by bilateral microinjections of the nonselective synapse blocker CoCl2 on the baroreflex response in rats. Reversible ablation of the bed nucleus by bilateral microinjection of CoCl2 did not affect baseline blood pressure or heart rate, suggesting no tonic influence of bed nucleus on the cardiovascular system. Pretreatment with CoCl2 did not affect the tachycardic response to blood pressure decreases caused by intravenous infusion of sodium nitroprusside, but enhanced bradycardic responses evoked by blood pressure increases caused by intravenous infusion of phenylephrine. Present data suggest that synapses within the bed nucleus have a tonic inhibitory influence on the baroreflex parasympathetic component.
Crestani
Carlos C
CC
Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil. cccrestani@yahoo.com.br
Alves
Fernando H F
FH
Resstel
Leonardo B M
LB
Corrêa
Fernando M de A
FM
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000818:Animals; D017704:Baroreflex / Q000187:drug effects / Q000502:physiology*; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D003035:Cobalt / Q000494:pharmacology; D004347:Drug Interactions; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D008845:Microinjections / Q000379:methods; D010656:Phenylephrine / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012686:Septal Nuclei / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors
D000316:Adrenergic alpha-Agonists; D010656:Phenylephrine; D003035:Cobalt; C018021:cobaltous chloride