Acetylcholine in the posterior hypothalamic nucleus is involved in the elevated blood pressure in the spontaneously hypertensive rat.
Intravenous injection of physostigmine, 40 and 80 ug/kg, in unanesthetized normotensive rats increased systolic blood pressure (SBP) by 21 +/- 3 and 42 +/- 7 mmHg. This pressor response was 80% inhibited by intracerebroventricular (icv) injection of hemicholinium-3 (HC-3), 20 ug. Simultaneous icv injection of HC-3 and choline (365 ug) prevented the inhibition of the pressor response by HC-3. In spontaneously hypertensive rats, injection of HC-3 either icv (20 ug) or bilaterally into the posterior hypothalamic nuclei (1 ug) decreased SBP by about 40 mmHg. The effect of intrahypothalamic HC-3 was completely blocked by simultaneous injection of choline (24.3 ug) into the same site. The hypotensive effect of icv HC-3 was completely blocked by icv choline (243 ug) and was inhibited up to 60% by injections of choline (24.3 ug) into the posterior hypothalamic nuclei.
Brezenoff
H E
HE
Department of Pharmacology, University of Medicine and Dentistry of New Jersey, Newark 07103.
Xiao
Y F
YF
D000109:Acetylcholine / Q000502:physiology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology*; D002794:Choline / Q000008:administration & dosage / Q000494:pharmacology; D006426:Hemicholinium 3 / Q000008:administration & dosage / Q000494:pharmacology; D006973:Hypertension / Q000503:physiopathology*; D007031:Hypothalamus / Q000187:drug effects / Q000502:physiology*; D007276:Injections, Intraventricular; D007700:Kinetics; D008297:Male; D010830:Physostigmine / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D011918:Rats, Inbred SHR; D011919:Rats, Inbred Strains
D006426:Hemicholinium 3; D010830:Physostigmine; D002794:Choline; D000109:Acetylcholine