These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.
Pubmed for Handhelds
PUBMED FOR HANDHELDS
Search MEDLINE/PubMed
Title: Hemodynamic and plasma atrial natriuretic factor responses to cardiac volume loading in young versus older normotensive humans. Author: Legault L, van Nguyen P, Holliwell DL, Leenen FH. Journal: Can J Physiol Pharmacol; 1992 Dec; 70(12):1549-54. PubMed ID: 1301232. Abstract: To assess the effects of age on responsiveness of atrial natriuretic factor (ANF) release, and the possible contribution of cardiac sympathetic activity, in young (n = 8) and older normotensives (n = 7), the effects of cardiac volume load on plasma ANF, central venous pressure, and general hemodynamics were evaluated. Studies were performed after pretreatment with placebo or 80 mg propranolol. Cardiac volume loading increased central venous pressure by 3-5 mmHg (1 mmHg = 133.3 Pa); beta-blockade did not affect this response. Cardiac volume load caused significant increases in heart rate (10-15 beats/min) and cardiac index (by 0.7-0.8 L.min-1.m-2) and decreases in plasma catecholamines. Propranolol attenuated the increases in heart rate and cardiac index. These hemodynamic responses did not differ significantly between the two groups of subjects. Cardiac volume load significantly increased plasma ANF, by 87 +/- 21 pg/mL in the young normotensives and by 212 +/- 33 pg/mL in the older normotensives (p < 0.01, young vs. older). beta-Blockade did not affect this different response. Our results show that the plasma ANF response to volume loading is potentiated by aging. Although differences in atrial stretch cannot be excluded, this effect may relate to the decrease in clearance of plasma ANF occurring with aging.[Abstract] [Full Text] [Related] [New Search]