Abstract
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.
Original language | English |
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Journal | American Journal of Physiology - Regulatory Integrative and Comparative Physiology |
Volume | 276 |
Issue number | 5 45-5 |
Publication status | Published - May 1999 |
Externally published | Yes |
Keywords
- Atrial natriuretic factor
- Atrial natriuretic peptide
- Blood pressure
- Brain natriuretic peptide
- Hemoconcentration
- In vivo
- Kidney
- Plasma renin activity