[Characteristics of transcapillary fluid exchange in working skeletal muscles perfused in various ways]

Acute experiments in cats revealed by means of volumometry of extracorporeal blood flow that the exchange surface of the microcirculation bed in working skeletal muscles increased irrespective of whether they were perfused under constant pressure or in constant blood flow. Capillary hydrostatic pressure depended on the perfusion mode: it decreased in conditions of stabilized blood expenditure through muscles, and increased in constant pressure perfusion. An increase of the capillary filtration coefficient is considered from the standpoint of dilatory effect of metabolites on precapillary sphincters. Changes of pre-and postcapillary resistance take part in shifts of fluid movement in the muscle during contraction.