Brain atrial natriuretic peptide family abolishes cardiovascular haemodynamic alterations caused by hypertonic saline in rats.
1. Regional haemodynamic alterations caused by hypertonic NaCl solution (Hi-Salt; 10%, 10 microL) injected intracerebroventricularly (i.c.v.) were investigated by using radioactive microspheres in anaesthetized rats. 2. Intracerebroventricular injections of Hi-Salt increased regional vascular resistance of visceral organs, including the kidney, and elevated plasma levels of vasopressin. 3. Intracerebroventricular pretreatment with TCV-11974 (50 micrograms/10 microL/nat), an angiotensin AT1 receptor antagonist, attenuated the pressor response and vasopressin release to subsequently injected Hi-Salt, but did not affect regional haemodynamic effects of i.c.v. Hi-Salt on vascular resistance. 4. In contrast, i.c.v. pretreatment with atrial natriuretic polypeptide (ANP) or type-C natriuretic polypeptide (CNP) almost completely abolished the haemodynamic changes and vasopressin release caused by i.c.v. Hi-Salt. 5. The present findings indicate that a natriuretic family in the brain may be involved to a great degree in the central regulation of salt-induced hypertension in rats, while brain angiotensin II is likely to participate only in vasopressin release.
Sakamoto
M
M
Department of Clinical Laboratory and Medicine, Kyoto Prefectural University of Medicine, Japan.
Nishimura
M
M
Takahashi
H
H
D057911:Angiotensin Receptor Antagonists; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology* / Q000502:physiology; D006439:Hemodynamics / Q000187:drug effects* / Q000502:physiology; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000494:pharmacology* / Q000502:physiology; D020098:Natriuretic Peptide, C-Type / Q000494:pharmacology* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D011945:Receptors, Angiotensin / Q000502:physiology; D012039:Regional Blood Flow / Q000187:drug effects; D012462:Saline Solution, Hypertonic / Q000008:administration & dosage*; D014655:Vascular Resistance / Q000187:drug effects
D057911:Angiotensin Receptor Antagonists; D011945:Receptors, Angiotensin; D012462:Saline Solution, Hypertonic; D020097:Natriuretic Peptide, Brain; D020098:Natriuretic Peptide, C-Type; D009320:Atrial Natriuretic Factor