Arteriolar Network Architecture and Vasomotor Function With Ageing in Mouse Gluteus Maximus Muscle

摘要: Physical diminishes with ageing, but little is known of how the microvascular supply to skeletal muscle fibres affected. To test hypothesis that ageing alters blood flow control, we investigated network architecture and vasomotor responses arterioles in gluteus maximus young (2-3 months), adult (12-14 months) old (18-20 C57BL6 male mice (n = 83) (Young, Adult Old, respectively). Microvascular casts revealed total number, length surface area arteriolar segments (diameter, 10-50 microm) were not significantly different across age-groups. However, for diameter 30 microm, tortuosity branch angles increased age (P < 0.05). In anaesthetized mice, second-order (2A) distributing had similar resting (17 +/- 1 maximal (37 diameters responsiveness cumulative (10(-10)-10(-4) M) superfusion acetylcholine or phenylephrine. With superfusate oxygen level raised from 0 21%, 2A constriction Young (11 was greater 0.05) than Old (5 microm). Observed mm upstream microiontophoresis ACh (1 microA, s), conducted vasodilatation 10 microm Young, 17 6 contractions (2, 4 8 Hz; s) similarly age-groups (6 1, 11 18 Muscle mass active tension yet postcontraction recovered more rapidly versus maintained during impairment attenuation may compromise exercise tolerance.