THE PRESSOR EFFECT OF PEPTONE IN THE RAT

Peptone normally causes a rise of blood pressure in rats. Since the pressor response was not abolished or even diminished by adrenalectomy, it could not have been caused by a release of pressor substances from the adrenal glands. The group of drugs (dibenamine, dihydroergotamine, ergotamine, tolazoline, nicotine and hexamethonium) which antagonize or block the peptone‐induced pressor action suggests that the pressor effect may be secondary to a release of sympathin by the stimulation of sympathetic ganglia. Since it was not possible to duplicate the pressor response to peptone by either 48/80 or histamine, the hypothesis that peptone acts by liberating histamine can be ruled out.