Toxicity of Histamine and Dial with Urethane in Intact and Adrenalectomized Hamsters. ∗

To select suitable doses of histamine, in a study of the effect of a chemical stress on peripheral circulation in the cheek pouch of the golden hamster (Mesocricetus auratus), data on toxicity of this substance in hamsters were accumulated. Since our observations of the circulation during stress with histamine necessitated the use of anesthesia, we have determined the toxicity of combinations of histamine and the anesthetic of choice, dial with urethane, selected because of sustained action from single doses. So far as we know, detailed information on the toxicity of histamine for hamsters has not been reported, and in view of the increasing use of this animal for experimental purposes an account of our work may be useful.

Methods. Tests were performed on 467 male hamsters, 8 to 10 weeks old, weighing 80 to 100 g. Of these, 271 were intact, 166 had been adrenalectomized 4 or 12 days previously, and 30 were sham-operated controls. The histamine used in most of the experiments was the chemically-pure base (Fisher). In previous work this form of histamine gave more uniform results, although more toxic than the acid phosphate (Burroughs-Wellcome) which has been commonly employed in adrenal studies. A few tests with the acid phosphate were done in 34 hamsters. Intra-peritoneal injections of 5 to 10% histamine were used in adrenalectomized hamsters and a 20% solution was used for intact hamsters. Anesthesia was induced by dial with urethane (hereinafter referred to as DU), containing 0.1 g diallylbarbituric acid, 0.4 g urethane, 0.4 g monoethylurea per cc (Ciba Pharmaceutical Products, Inc.). Single doses of 0.1 cc per 100 g body weight injected intraperitoneally provided a constant level of anesthesia within one hour and lasting for more than 5 hours.