Abstract
133Xe clerance was used for cutaneous perfusion measurements on rats. A study is presented in which some factors influencing the clearance are analyzed. The mean clearance value for a group of five animals was almost constant when followed during a period of two to three weeks. The depth of anaesthesia influenced the clearance. The clearance was somewhat lower when the injected volume was increased. Local injection of the vasoconstrictors noradrenaline and felypressin caused a distinct lowering of the clearance, whereas this was enhanced by body heating. Available evidence makes the use of the present 133Xenon clearance method possible for elucidating variations in the blood flow in circumscribed areas where a direct method of measurement is difficult to apply.