Reductions in basal limb blood flow and vascular conductance with human ageing: role for augmented α‐adrenergic vasoconstriction

• DOI: 10.1111/j.1469-7793.2001.00977.x
• Publication Date: 2004-08-05T08:59:00Z
• Authors: Frank A. Dinenno; Hirofumi Tanaka; Brian L. Stauffer; Douglas R. Seals
• Keywords: Kinesiology; Health science

1 Basal whole-limb blood flow and vascular conductance decrease with age in men. We determined whether these age-associated changes limb haemodynamics are mediated by tonically augmented sympathetic α-adrenergic vasoconstriction. 2 Seven young (28 ± years; mean ±s.e.m.) eight older (64 years) healthy, normotensive adult men were studied. Baseline femoral artery (Doppler ultrasound) calculated 29 31 % lower, respectively, resistance was 53 higher the (all P < 0.001). 3 Local (intra-femoral artery) receptor blockade phentolamine evoked greater increases (105 11 vs. 60 6 %) (125 13 66 7 %), reductions (55 39 experimental of compared As a result, eliminated significance differences absolute levels (500 51 551 35 ml min−1), (6.02 0.73 6.33 0.26 U), (0.17 0.03 0.16 0.01 U; P= 0.4–0.8, n.s.). Femoral control unaffected administration contralateral (experimental) limb. Complete demonstrated absence vasoconstriction response to cold pressor test. propranolol administered for any β-adrenergic effects phentolamine. Propranolol did not affect or limbs. 4 Our results indicate that age-related basal largely chronically elevated This may have important physiological pathophysiological implications ageing human.