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Different effects of alpha-human atrial natriuretic peptide and nitroglycerin on cardiac dimensions in humans
T Imaizumi1, A Takeshita, M Yoshida
1Research Institute of Angiocardiology and Cardiovascular Clinic, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Insights
Alpha-human atrial natriuretic peptide (alpha-hANP) did not change cardiac dimensions, unlike nitroglycerin, despite similar effects on central venous pressure. This suggests ANP may dilate cardiac chambers in humans.
Area of Science:
- Cardiology
- Physiology
- Pharmacology
Background:
- Alpha-human atrial natriuretic peptide (alpha-hANP) is a hormone with known effects on cardiovascular function.
- Understanding its impact on cardiac dimensions is crucial for clinical applications.
Purpose of the Study:
- To investigate the effects of alpha-hANP on cardiac dimensions (left atrial and left ventricular diastolic diameters) in humans.
- To compare these effects with those of nitroglycerin (NG).
Main Methods:
- Echocardiography was used to measure cardiac dimensions under various conditions.
- Lower body negative pressure (LBNP) was applied to simulate changes in central venous pressure (CVP).
- Intravenous infusions of saline, alpha-hANP, or NG were administered to different subject groups.
Main Results:
- LBNP decreased CVP and cardiac dimensions.
- Both alpha-hANP and NG reduced CVP, indicating similar effects on venous return.
- Nitroglycerin decreased cardiac dimensions, whereas alpha-hANP did not alter them.
- alpha-hANP caused decreases in CVP and pulmonary capillary wedge pressure.
Conclusions:
- Alpha-hANP may induce vasodilation, leading to cardiac chamber dilation in humans.
- Unlike NG, alpha-hANP's effect on cardiac dimensions differs despite similar CVP reduction.
Abstract:
This study aimed to examine whether alpha-human atrial natriuretic peptide (alpha-hANP) alters cardiac dimensions in humans. Left atrial (LA) and left ventricular diastolic (LV) diameters were measured by echocardiography at control and with lower body negative pressure (LBNP) at -10 and -20 mmHg during intravenous (IV) infusion of saline or alpha-hANP at a dose of 0.03-0.04 microgram/kg per minute (n = 8). Studies were also done during IV infusion of saline or nitroglycerin (NG) at a dose of 10-15 micrograms/kg per minute in another group of subjects (n = 6). LBNP decreased central venous pressure (CVP) and the LA and LV diameter. alpha-hANP lowered CVP at rest and with LBNP at -10 and -20 mmHg compared with corresponding values during saline infusion; NG produced comparable decreases in CVP, which suggests that decreases in venous return caused by the two drugs were similar. However, NG decreased, but alpha-hANP did not alter the LA and LV diameter at rest or with LBNP. In another group of subjects (n = 4), we observed that alpha-hANP caused comparable decreases in CVP and pulmonary capillary wedge pressure. These data suggest that ANP may dilate the cardiac chambers in humans.