EFFECT OF ANTIHISTAMINE DRUGS ON THE ADRENAL CORTICAL RESPONSE TO HISTAMINE AND TO STRESS

¹ Department of Pharmacology, State University of New York Medical School at Syracuse, the Bristol Laboratories, Inc.
² Department of Zoology, Syracuse University, Syracuse, N. Y.

1. The administration by stomach tube of equivalent amounts of three antihistamine drugs (Phenoxadrine, Benadryl, Pyribenzamine) does not cause a significant change in adrenal ascorbic acid concentration in the rat.

2. The intraperitoneal injection of histamine phosphate (10 mgm./kgm. of body weight) lowers the adrenal ascorbic acid concentration from 400 mgm./100 gm. of tissue to 277 mgm./100 gm. of tissue.

3. Histamine injection one hour after pretreatment with Phenoxadrine or Pyribenzamine results in a smaller fall in adrenal ascorbic acid than that in control animals. Pretreatment with Benadryl, however, does not prevent or modify the adrenal ascorbic acid response to histamine.

4. Under the conditions of these experiments Benadryl administration was followed consistently by a small but significant hyperglycemia while Phenoxadrine and Pyribenzamine did not elicit this response.

5. Pretreatment with an antihistamine drug did not prevent or modify the adrenal ascorbic acid response to the stress of intraperitoneal carbon tetrachloride administration.

6. A description is given of the hypotensive effect of intraperitoneally administered histamine and the modification of this effect by antihistamine drugs in the rat.