SIALOGENIC ACTION OF SUBSTANCE P AND A PHYSALAEMIN-LIKE OCTAPEPTIDE UPON INFUSION IN VARIOUS VESSELS

1. The physalaemine-like octapeptide Pro-Asn-Lys-Phe-Tyr-Gly-Leu-Eti(NH2) and substance P were infused into the V. lienalis, V. femoralis and A. carotis of the dog. The secretion of the parotid and submandibular glands were compared. 2. The parotid gland responded to lower doses and produced larger amounts of secretion than the submandibular gland. The glands responded in the reverse order to carbachol. 3. Infusion of the peptide into the femoral vein elicited a greater secretion from the parotid gland than the infusion of the same doses into the splenic vein; it can be concluded that an inactivation of the peptide takes place in the liver. 4. Intracarotid infusion of the peptide in amounts which produced maximal secretion of the ispilateral gland also caused a contralateral secretion. The effect on the contralateral side was smaller than that of the same dose infused into the femoral vein; part of the peptide seems to dissappear during passage through the carotid circulation. © 1968 Springer-Verlag.