Lower skeletal muscle nutritive blood flow in older women is related to eNOS protein content.

The relationship between muscle endothelial nitric oxide synthase (eNOS) content and nutritive flow was investigated in nonobese sedentary young (27.7 +/- 2.6 years) and older (56.6 +/- 2.1 years) women matched for body composition and (2)peak. A muscle biopsy was taken and nutritive blood flow was determined under resting conditions in the vastus lateralis of the quadriceps femoris muscle group. Muscle eNOS protein content correlated with muscle nutritive blood flow (r =.66, p <.05) and body mass index (r =.74, p <.05), but it did not correlate with VO(2)peak. Muscle eNOS content was 35% lower in young than in older women (266 +/- 36 vs 407 +/- 53 pg/mg total protein; p <.05). The mean ethanol outflow-to-inflow ratio was higher (indicating lower nutritive flow) in older and young women (.666 +/-.042 and.546 +/-.043, respectively: p <.05). Resting skeletal nutritive blood flow and muscle eNOS content was lower in older than in young women. A low muscle eNOS protein content may be linked to a low muscle nutritive blood flow in healthy women.