Abstract
The possibility always exists that an undesirable amount of histamine or histaminelike depressor substances are included as contamitants in antibiotics and biological preparations, because these preparations are produced by fermentation processes or prepared from natural origins. In addition, it is possible that the administration of such preparations contaminated with depressor substances may be a cause of allergic responses. From the above-mentioned reason, it is demanded in official to determine whether the depressor substances are contained beyond the allowance or not in these preparations.
The official assay method prescribed for depressor substances is based upon a transient fall in blood pressure of anesthetized cats at intravenous administration of very small doses of histamine.
The present authors, with the purpose of standardizing the official method for the determination of histamine-like depressor substances in their various products, examined the factors that influence the sensitivity of cat blood pressure to histamine. The factors selected for this study were as follows: sexual difference, seasonal variation, the kind of anesthetic agent and repetition of administration of histamine. The effects of these factors influencing the depressor effect of histamine in cats will be demonstrated statistically by the data in this study and from those in their past routine assays.
