Is Large Solute Transport Active or Passive?
Effects of Temperature Reduction Rippe et al. [48] investigated the effects of tissue cooling on transvascular albumin passage in the rat hindquarter microvascular bed during maximal arteriolar dilatation in experiments which were designed as paired, parallel perfusions of one test hindquarter at 14°C and one control at 36°C. As perfusate, oxygenated, heparinized horse serum or mixtures of horse serum and bovine serum albumin was used. Hindquarters were arranged for a gravimetric technique, allowing continuous monitoring of tissue weight, arterial and venous pressures and perfusate flow. Whereas the control animal had a rectal temperature of 36–37°C, the rectal temperature in the test animal could, as mentioned above, be reduced (via cooling of the perfusate) to 14–16°C. Radiolabelled serum albumin (125I-albumin, RISA) was added to the perfusate and perfusion was continued for 40–60 min, after which tracer-free perfusate was employed to effectively wash the hindquarters free from trace
