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Vasodilatory effects of B-type natriuretic peptide are impaired in patients with chronic heart failure
M Nakamura1, N Arakawa, H Yoshida
1Second Department of Internal Medicine, Iwate Medical University, Morioka, Japan.
Insights
B-type natriuretic peptide (BNP) and atrial natriuretic peptide (ANP) show reduced vasodilator effects in congestive heart failure (CHF) patients compared to healthy individuals. BNP and ANP responses were similar in CHF patients, unlike in healthy subjects.
Area of Science:
- Cardiovascular Physiology
- Endocrinology
- Pharmacology
Background:
- Natriuretic peptides, including B-type natriuretic peptide (BNP) and atrial natriuretic peptide (ANP), are crucial for vascular tone regulation.
- Their roles in healthy individuals and congestive heart failure (CHF) are presumed similar, but direct comparative data are lacking.
Purpose of the Study:
- To directly compare the vasodilator effects of BNP and ANP in patients with CHF and age-matched healthy subjects.
- To investigate potential differences in natriuretic peptide action and metabolism between healthy and CHF states.
Main Methods:
- Utilized plethysmography to assess forearm blood flow (FBF) responses to graded intra-arterial infusions of ANP and BNP.
- Measured forearm cyclic GMP (cGMP) spillover as an indicator of peptide activity.
- Included 15 patients with CHF and 16 healthy subjects.
Main Results:
- Both BNP and ANP elicited significantly lower FBF and cGMP spillover responses in CHF patients compared to healthy subjects.
- In healthy subjects, ANP induced greater FBF and cGMP spillover changes than BNP.
- In CHF patients, there were no significant differences in FBF or cGMP spillover between BNP and ANP.
Conclusions:
- The metabolism and/or action of natriuretic peptides (BNP and ANP) appear altered in the state of congestive heart failure.
- BNP and ANP may not be equally important in CHF vascular regulation as previously thought, with differing responses compared to healthy states.
Background:
B-type natriuretic peptide (BNP) and atrial natriuretic peptide (ANP) are secreted from the heart and are thought to be equally important factors in the regulation of vascular tone in health and in congestive heart failure (CHF). However, no studies directly compare vasodilator effects of these peptides in healthy subjects and in patients with CHF.
Methods:
Plethysmography was used to determine the vasodilatory effects of BNP and to compare these to the effects of ANP in patients with CHF (n = 15) and age-matched healthy subjects (n = 16). Graded doses of ANP and BNP (8, 16, 32, and 48 pmol/min per 100 ml of tissue volume for both) were administered randomly into the brachial artery. Forearm blood flow (FBF) was measured, and cyclic GMP (cGMP) spillover was calculated.
Results:
Responses in FBF to both peptides in CHF were significantly lower than those of healthy subjects (BNP p < 0.05; ANP p < 0.01). Similarly, forearm spillover of cGMP was significantly lower in CHF than in healthy subjects (BNP p < 0.05; ANP p < 0.01). When vascular responses in healthy subjects were compared between BNP and ANP, BNP-induced changes in FBF (p < 0.05) and forearm cGMP spillover (p < 0.01) were significantly less than changes induced by ANP. In CHF, though, FBF change and cGMP spillover induced by the two peptides were not significantly different.
Conclusions:
These results suggest that the metabolism and action of these natriuretic peptides in CHF may differ from the healthy state.