Determination of reactivity of resistance blood vessels in the isolated perfused legs of animals with inflammation as exemplified in adjuvant arthritis.

Vasodepression was found ex vivo in the isolated perfused hind legs of rats, mice and guinea-pigs with paw inflammation using maximum pressure amplitude, EAm, pD2-value and intrinsic sensitivity (i.s.) as the test parameters of dose-response curves of vasopressor substances (noradrenaline, lys- and arg-vasopressin, angiotensin II, substance P, Na2-ATP). Vasodepression is strong in the anaphylactic and dextran paw edema, moderate in the carrageenin paw edema and adjuvant arthritis, but weak in the pertussis vaccine and kaolin paw edema. It is partly long-lasting, does not closely correlate with edema strength and can also be shown in the contralateral non-inflamed leg. Thus, a vasoreactivity depressing factor(s) must be liberated from the site of inflammation and reach the general circulation. Here, the method is described using the adjuvant arthritis as an example.