PT - JOURNAL ARTICLE AU - EDWIN J. DEBEER AU - AXEL M. HJORT AU - CHARLES A. COOK TI - AN ANALYSIS OF SEASONAL INFLUENCES ON THE RESPONSE OF ALBINO MICE TO ANESTHETICS DP - 1939 Jan 01 TA - Journal of Pharmacology and Experimental Therapeutics PG - 46--60 VI - 65 IP - 1 4099 - http://jpet.aspetjournals.org/content/65/1/46.short 4100 - http://jpet.aspetjournals.org/content/65/1/46.full SO - J Pharmacol Exp Ther1939 Jan 01; 65 AB - No significant seasonal variations in the toxicity of either n-propyl-o-tolyl urea or the sodium salt of ethyl-n-hexyl barbituric acid were found in any of the four periods investigated. The intraseasonal variations of the toxicity of the urea compound could be ascribed to chance alone, with the exception of the month of July, but the intraseasonal variations of the barbiturate indicated each time that some other factor besides chance was influencing the results. In the hypnotic range, it was found with both compounds that the results of the month of January differed significantly from those of the other seasonal periods. Also, significant variations were encountered twice in other experiments with the urea compound in approximately the same season but these were associated with increased instead of decreased potency. No detectable error in the determination of hypnotic potency was introduced in these experiments by making dosage proportional to body weight. No diurnal variations in hypnotic potency were found. No relationship between hypnotic potency and either barometric pressure or environmental temperature was established. The average detectable significant difference at the 50 per cent response dose for the hypnotic action of n-propyl-o-tolyl urea was found to be surprisingly small, i.e., 0.000675 mM., per 20 gram mouse.