Modelling oxygen capillary supply to striated muscle tissues

The ability to characterise functional capillary supply (FCS) plays a key role in developing effective therapeutic interventions for numerous pathological conditions, such as chronic ischaemia in skeletal or cardiac muscle. Detailed tissue geometry, such as muscle fibre size, has been incorporated into indices of FCS by considering the distribution of Voronoi tessellations (‘capillary domains’) generated from vessel locations in a plane perpendicular to muscle fibre orientation, implicitly assuming that each Voronoi polygon represents the area of supply of its enclosed capillary. However, to assess the capacity of FCS in muscle, we are naturally led to use a modelling framework that can account for the local anatomic and metabolic heterogeneities of muscle fibres. Such a framework can be used to explore the validity of the Voronoi polygon representation of FCS regions while also providing a general platform for robust predictions of FCS

Blunted angiogenesis and hypertrophy are associated with increased fatigue resistance and unchanged aerobic capacity in old overloaded mouse muscle.

We hypothesize that the attenuated hypertrophic response in old mouse muscle is (1) partly due to a reduced capillarization and angiogenesis, which is (2) accompanied by a reduced oxidative capacity and fatigue resistance in old control and overloaded muscles, that (3) can be rescued by the antioxidant resveratrol. To investigate this, the hypertrophic response, capillarization, oxidative capacity, and fatigue resistance of m. plantaris were compared in 9- and 25-month-old non-treated and 25-month-old resveratrol-treated mice. Overload increased the local capillary-to-fiber ratio less in old (15 %) than in adult (59 %) muscle (P < 0.05). Although muscles of old mice had a higher succinate dehydrogenase (SDH) activity (P < 0.05) and a slower fiber type profile (P < 0.05), the isometric fatigue resistance was similar in 9- and 25-month-old mice. In both age groups, the fatigue resistance was increased to the same extent after overload (P < 0.01), without a significant change in SDH activity, but an increased capillary density (P < 0.05). Attenuated angiogenesis during overload may contribute to the attenuated hypertrophic response in old age. Neither was rescued by resveratrol supplementation. Changes in fatigue resistance with overload and aging were dissociated from changes in SDH activity, but paralleled those in capillarization. This suggests that capillarization plays a more important role in fatigue resistance than oxidative capacity

Calculation of oxygen pressures in tissue with anisotropic capillary orientation I : two-dimensional analytical solution for arbitrary capillary characteristics

Contains fulltext : 21615___.PDF (publisher's version ) (Open Access

Calculation of oxygen pressures in tissue with anisotropic capillary orientation II : coupling of two-dimensional planes

Contains fulltext : 21614___.PDF (publisher's version ) (Open Access

The effect of blood flow on oxygen extraction pressures calculated in a model of pointlike erythrocyte sources for rat heart

Contains fulltext : 23121___.PDF (publisher's version ) (Open Access

Reconsidering the Effect of Local Plasma Convection in a Classical Model of Oxygen transport in Capillaries

Contains fulltext : 22861___.PDF (publisher's version ) (Open Access

Mathematical model of erythrocytes as point-like sources

Contains fulltext : 20615___.PDF (publisher's version ) (Open Access