Atrial, B-type, and C-type natriuretic peptides cause mesenteric vasoconstriction in conscious dogs

• Published in: American journal of physiology. Regulatory, integrative and comparative physiology Vol. 276; no. 5; pp. 1443 - R1452
• Main Authors: Woods, Robyn L, Jones, Marcus J. M
• Format: Journal Article
• Language: English
• Published: United States 01.05.1999
• Subjects: Animals; Atrial Function; Atrial Natriuretic Factor - pharmacology; Blood Pressure - physiology; Consciousness; Dogs; Dose-Response Relationship, Drug; Ganglionic Blockers - pharmacology; Hematocrit; Kidney - physiology; Male; Mesenteric Arteries - drug effects; Mesenteric Arteries - physiology; Natriuretic Peptide, Brain; Natriuretic Peptide, C-Type - pharmacology; Pentolinium Tartrate - pharmacology; Renin - blood; Urination - drug effects; Vasoconstriction - drug effects; Vasoconstriction - physiology
• ISSN: 0363-6119; 0002-9513; 1522-1490
• DOI: 10.1152/ajpregu.1999.276.5.r1443

1  Howard Florey Institute, University of Melbourne, Parkville, Victoria 3052; and 2  Baker Medical Research Institute, Prahran, Victoria 3181, Australia Cardiovascular responses were compared with equimolar infusions of B-type (BNP) and C-type (CNP) with atrial natriuretic peptide (ANP) in conscious, instrumented dogs. On separate days, each natriuretic peptide or vehicle was infused (intravenously) at step-up doses of 2, 5, 10, and 20 pmol · kg 1 · min 1 (20 min each dose) to increase circulating levels of the infused peptide from ~2- to 20-fold. Like ANP, infusions of BNP caused dose-related increases ( P  < 0.05) in mesenteric vascular resistance, urine flow, natriuresis, and hematocrit (changes at highest doses were 60 ± 9, 334 ± 113, 313 ± 173, and 12 ± 2%, respectively). BNP also lowered ( P  < 0.05) plasma renin activity ( 43 ± 11%) and arterial pressure ( 10 ± 3%). Effects of BNP were independent of reflex sympathetic activation, since autonomic ganglion blockade did not attenuate the responses. CNP infusions had little effect except to increase ( P  < 0.05) mesenteric vascular resistance (27   ± 10%) and plasma ANP (41 ± 7%). Cardiovascular actions of BNP, like those of ANP, counteract the renin-ANG system and may protect the heart by lowering cardiac preload (venous return) and afterload (arterial pressure) while maintaining blood flow to extrasplanchnic regions. atrial natriuretic factor; blood pressure; atrial natriuretic peptide; brain natriuretic peptide; hemoconcentration; in vivo; kidney; plasma renin activity