Variations in Response of Minute Vessels in the Cecal Mesentery of the Rat to Topically Applied Epinephrine

Publisher Website
Google Scholar
Abstract
The use of the rat cecal mesentery vessels for detection of vaso-reactive substances by the method suggested by Zweifach is critically tested. Since interpretation of any vaso-reactive agent is made by this test in terms of a change in the concn. of epinephrine (added topically to the exposed vessels) required to produce a response, it is argued that the threshold under basic conditions should be stable if changes in apparent threshold following any modification is to be significant. The results show that normal thresholds are not stable. Considerable variation occurs from animal to animal and worse, even in the same animal during a sequencial series of tests. The anesthetic level affects the apparent threshold even under the best conditions. Arbitrary decisions of the operator and empirical conditions of the test procedure are also shown to produce highly selective data. Results of such tests should be interpreted with extreme caution.