In the present research the epinephrine in the suprarenal vein blood, collected by means of the cava pocket from rabbits, cats, dogs, goats and a badger, and in the extract, of the suprarenal gland left after the cava pocket experiment according to the procedure of Folin, Cannon and Denis, of rabbits, dogs, goats and a badger was estimated, adrenalin chloridc of the Sankyo Co. being used as the standard, by means of the rabbit intestine strip, the cat paradoxical eye method of Sugawara, and Folin's colorimetric procedure. The values of one and the same sample were compared with each other. In preparing the cava pocket all the animals were anaesthetized except rabbits.
(1) The rabbit intestine strip method yielded invariably higher value for the cava pocket blood of cats than the paradoxical eye reaction, in accordance to the previous finding of Sugawara. The ratio (Eye-Intestine) was calculated as 1:1.2-1:2.3, on an average 1:1.8, against 1:1.2-1:2.7, mean 1:1.9 for ten cats of his.
(2) In the case of rabbits, contrary to that of cats, the paradoxical pupil reaction yielded invariably a higher value for the suprarenal blood than did the rabbit intestine strip method; the ratio being-(Eye:Intestine) 1.2:1-4:1, mean 2.2:1.
Explanations of such events are tentatively given in the text. We are not, however, in a position to present them as anything more than an attractive speculation.
(3) The suprarenal vein blood of dogs, goats and a badger afforded generally similar results as in cats; that is, the value obtainable by the rabbit intestine strip method was comparatively greater than that by the other. The ratio (Eye:Intestine) was 1:1.4 (1:1-1:3.0) for dogs, 1:1.9 (1:1.7-1:2.2) for goats and 1:1.6 for the badger.
(4) Of the extract of the whole gland of dogs, the value achieved by the rabbit intestine was highest compared with those by the paradoxical pupil reaction and the colorimetric method of Folin. The average ratios were-Eye: Intestine 1:1.6, Eye: Folin 1:1.2 and Folin: Intestine 1:1.3.
Of the extract of goats, -Eye: Intestine 1:2.2, Eye:Folin 1:1.6 and Folin:Intestine 1:1.4.
Of the extract of badger, -Eye:Intestine 1:3.2, Eye: Folin 1:2.1 and Folin:Intestine 1:1.5.
Of the extract of rabbits, -Eye: Intestine 1:1.2, Eye: Folin 1:4.1 and Folin: Intestine 3.7:1.
The Cortical extract of goat and extract of the whole gland of rabbits yielded an especially high value in the colorimetric test of Folin. It must be assumed that in the cortical extract of goats there exist a substance or some substances which act positively to the Folin, but do not react to the biological test, as in the suprarenal body of rabbits.