Microinjection of S-nitrosocysteine into the nucleus tractus solitarii of conscious rats decreases arterial pressure but L-glutamate does not.
Unilateral microinjection of L-glutamate into the nucleus tractus solitarii of conscious rats increased arterial pressure and caused bradycardia while microinjection of S-nitrosocysteine into the same site of these animals caused hypotension and bradycardia. The responses to S-nitrosocysteine were blocked by prior microinjection of methylene blue into the nucleus tractus solitarii. The bradycardia and fall in arterial pressure induced by S-nitrosocysteine resemble more the cardiovascular changes in response to activation of baroreceptor afferents than the bradycardia and increase in arterial pressure induced by microinjection of L-glutamate into the nucleus tractus solitarii of conscious rats.
Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Brazil.
B H
BH
Machado
L G
LG
Bonagamba
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D001921:Brain / Q000187:drug effects*; D003545:Cysteine / Q000031:analogs & derivatives* / Q000494:pharmacology; D005971:Glutamates / Q000494:pharmacology*; D018698:Glutamic Acid; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D008845:Microinjections; D009569:Nitric Oxide / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D026403:S-Nitrosothiols
D005971:Glutamates; D026403:S-Nitrosothiols; D009569:Nitric Oxide; D018698:Glutamic Acid; C021315:S-nitrosocysteine; D003545:Cysteine