RT Journal Article
SR Electronic
T1 A STUDY OF THE POISONOUS SECRETIONS OF FIVE NORTH AMERICAN SPECIES OF TOADS
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 526
OP 542
VO 49
IS 4
A1 K. K. CHEN
A1 A. LING CHEN
YR 1933
UL http://jpet.aspetjournals.org/content/49/4/526.abstract
AB The parotid secretion of B. valliceps has been found to contain (a)cholesterol, (b) vallicepo-bufagin, C26H38O6, (c) vallicepo-bufotoxin, and (d) vallicepo-bufotenine (C11H12O2N2·C10H6O8N2S as a flavianate). Both vallicepo-bufagin and -bufotoxin have a digitaloid action physiologically. The average fatal dose of vallicepo-bufagin in cats is 0.2 mgm. per kilogram, its minimal emetic dose in pigeons is 0.2 mgm., and that in cats 0.08 mgm. per kilogram. The parotid secretion of B. fowleri has been shown to yield (a) cholesterol admixed with 1.1 parts of ergosterol per thousand, (b) fowlero-bufagin, C23H33O6, (c) fowlero-bufotoxin, and (d) fowlero-bufotenine (C13H20O2N2·C10H6O8N2S as a flavianate). Both fowlero-bufagin and -bufotoxin have a digitaloid action on animals. The average fatal dose of fowlero-bufagin in cats is 0.22 mgm. per kilogram; its minimal emetic dose in pigeons is 0.25 mgm., and in cats, 0.125 mgm. per kilogram. Fowlero-bufotenine raises the blood pressure, increases the tone of the cardiac contractions in frogs, and stimulates isolated smooth-muscle organs. Its pressor action is almost the same as that of cino-bufotenine, the ratio being 1:0.933 in favor of fowlero-bufotenine. The secretion expressed from the parotid and limb glands of B. alvarius has been found to contain (a) cholesterol admixed with 13.6 parts of ergosterol per thousand, (b) alvaro-bufotoxin, which has a digitaloid action, and (c) alvaro-bufotenine (C12H18O2N2·C10H6O8N2S as a flavianate), which exhibits a negligible pressor action and causes no increase in the tone of the heart contractions in frogs as observed with several other bufotenines. The parotid secretion of B. quercicus has been shown to contain (a) quercico-bufagin, C23H34O5, and (b) quercico-bufotenine, C12H18O2N2·C10H6O8N2S. The minimal emetic dose of quercico-bufagin in cats is 0.1 mgm., that in pigeons 0.15 mgm., and the average fatal dose in cats 0.1 mgm. per kilogram. Quercico-bufotenine has only slight pressor action, but it stimulates isolated smooth-muscle organs. Evidence has also been obtained for the occurrence of cholesterol and a bufotoxin. The parotid secretion of B. americanus has been found to contain americano-bufotenine, C12H18O2N2·C10H6O8N2S, which has a pressor action equal to 74 per cent of that of cino-bufotenine. Besides, it stimulates isolated smooth-muscle organs. Three different fractions have also been separated, which contain in amorphous form cholesterol, a bufagin, and a bufotoxin, respectively. The last two, as expected, possess a digitalis-like action.