Propranolol blocks the tachycardia induced by galanin (1-15) but not by galanin (1-29).
The efferent pathways involved in the tachycardia induced by intracisternal injections of the N-terminal galanin fragment (1-15) (GAL (1-15)) and galanin (GAL (1-29)) has been evaluated in rats pretreated with the cholinergic antagonist atropine or the beta-antagonist propranolol. The pretreatment with propranolol significantly blocked the tachycardic and vasopressor effect produced by intracisternal injection of GAL (1-15) (p<0.05), but the pretreatment with atropine did not modify these cardiovascular effects. However, the cardiovascular response elicited by GAL (1-29) is modified by the pretreatment with atropine (p<0.05) but not by propranolol. These findings demonstrate that the central cardiovascular action of GAL (1-15), but not GAL (1-29), is mediated by beta-receptor stimulation and this suggests the existence of a different pathway involved in the cardiovascular response produced by the N-terminal galanin fragment as compared with the parent molecule GAL (1-29).
Díaz-Cabiale
Zaida
Z
Departamento de Fisiología, Facultad de Medicina, Campus de Teatinos s/n, 29080, Málaga, Spain.
Cordón
M Paz
MP
Coveñas
Rafael
R
Rivera
Alicia
A
Yanaihara
Noboru
N
Fuxe
Kjell
K
González-Barón
Salvador
S
Narváez
José A
JA
D000818:Animals; D001285:Atropine / Q000494:pharmacology / Q000633:toxicity; D001794:Blood Pressure / Q000187:drug effects; D002946:Cisterna Magna; D019004:Galanin / Q000037:antagonists & inhibitors* / Q000633:toxicity; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D010446:Peptide Fragments / Q000037:antagonists & inhibitors*; D011433:Propranolol / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013610:Tachycardia / Q000139:chemically induced* / Q000188:drug therapy*; D013997:Time Factors
D010446:Peptide Fragments; C086813:galanin (1-15); D001285:Atropine; D019004:Galanin; D011433:Propranolol