Published in

The Company of Biologists, Journal of Experimental Biology, 2015

DOI: 10.1242/jeb.126664

Links

Tools

Export citation

Search in Google Scholar

Local capillary supply in muscle is not determined by local oxidative capacity

This paper is available in a repository.
This paper is available in a repository.

Full text: Download

Green circle
Preprint: archiving allowed
Orange circle
Postprint: archiving restricted
Orange circle
Published version: archiving restricted
Data provided by SHERPA/RoMEO

Abstract

It is thought that the prime determinant of global muscle capillary density is the mean oxidative capacity. However, feedback control during maturational growth or adaptive remodelling of local muscle capillarisation is likely more complex than simply matching O2 supply and demand in response to integrated tissue function. We tested the hypothesis that the maximal oxygen consumption (MO2max) supported by a capillary is relatively constant, and independent of the volume of tissue supplied (capillary domain). We demonstrate that local MO2max assessed by succinate dehydrogenase histochemistry 1) varied more than 100-fold between individual capillaries and 2) was positively correlated to capillary domain area in both human vastus lateralis (R=0.750, P<0.001) and soleus (R=0.697, P<0.001) muscles. This suggests that, in contrast to common assumptions, capillarisation is not primarily dictated by local oxidative capacity, but rather by factors such as fibre size, or consequences of differences in fibre size such as substrate delivery/metabolite removal.