TY - JOUR T1 - ON THE SMOOTH-MUSCLE STIMULATING ACTIVITY OF PREPARATIONS OF HEPARIN JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 58 LP - 64 VL - 132 IS - 1 AU - Jack Peter Green AU - Margaret Day AU - Michael Roberts Y1 - 1961/04/01 UR - http://jpet.aspetjournals.org/content/132/1/58.abstract N2 - Preparations of heparin, which have a greater amount of amino-containing compounds than can be accounted for as glucosamine, caused a contraction of the guinea pig ileum which was different in type from that induced by histamine and was not prevented by an antihistamine. The contraction was, in fact, similar to that observed with polypeptides. On hydrolysis of heparin (and of chondroitin sulfate and hyaluronate), histamine-like activity was evolved along with at least six ninhydrin-positive substances, including histidine. Histamine was demonstrated spectrofluorimetrically in the hydrolysates of bovine heparin. Under these conditions of hydrolysis, histamine was evolved from histidine, and this yield was greater when hydrolysis was carried out in the presence of heparin. It is concluded that preparations of heparin contain histidine and other ninhydrin-reacting materials besides glucosamine, and that at least some of these probably exist as a polypeptide(s), present as a contaminant. No evidence could be obtained for an enzymatic mechanism for producing histamine-like activity from preparations of heparin. Poly-L-lysylhistamine and two isoglucosides of histamine had no peptide-like action on the guinea pig ileum. Attempts to show the presence of substance P in neoplastic murine mast cells were unsuccessful, as were attempts to show the presence of significant amounts of bound histamine in these cells. ER -