title: Decreasing effects of glycerol-fractions extracted from ox diaphragm muscles on acetylcholine-induced contractions of smooth muscles.
abstract: Extracts of 5% glycerol obtained from ox diaphragm muscles were fractionated into four (A, B, C and D) with (NH4)2SO4. The activity as acetylcholine (ACh) receptor-like substance containing fraction was evidenced as follows; the ACh-induced contraction of tracheal muscles decreased with addition of the fraction, and such could not be attributed to the reaction with ACh receptors of tracheal smooth muscles. Fraction D had the most potent activity in the presence of neostigmine. This reaction induced by fraction D was reversed by addition of d-tubocurarine (d-TC). Fraction D was fractionated into three (I, II and III) by gel filtration on Sephadex G-75 with 50 mM phosphate buffer (pH 7.5). The purified fraction III was identified by electrophoresis, UV and visible absorption spectrum, and ion-exchange chromatography to be myoglobin. Pure myoglobin also proved to have a decreasing effect on ACh-induced contraction.
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D001001:Anura; D002417:Cattle; D005591:Chemical Fractionation; D002802:Cholinesterases / Q000494:pharmacology; D003864:Depression, Chemical; D003964:Diaphragm; D005990:Glycerol; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D011817:Rabbits; D014020:Tissue Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D014132:Trachea / Q000187:drug effects; D014403:Tubocurarine / Q000494:pharmacology
chemical_list: D014020:Tissue Extracts; D002802:Cholinesterases; D000109:Acetylcholine; D005990:Glycerol; D014403:Tubocurarine