Characterization of the heat-released substance from rat ileal muscle.
Previous studies have proposed that increasing the temperature around the rat isolated ileal muscles induces a heat-released substance (HRS) which causes a decrease in the contractile response. Therefore, we have studied various characteristics of this proposed HRS in animals exposed to heat-stress conditions. In these animals, the contraction of muscles in response to carbachol was decreased by increasing the temperature from 37 degrees C to 40 degrees C. Further, bathing the ileum in a conditioned medium prepared by incubation of the ileal muscle at 40 degrees C has shown less contraction at 40 degrees C than in presence of normal Krebs medium. In addition, conditioned mediums, prepared at 40 degrees C were run on SDS-polyacrylamide gel electrophoresis and have shown the presence of a distinct protein band at a m.w. region of 55 kDa. These results confirm our previous studies that increasing the temperature around the muscles induces the HRS that causes the decrease in the contractile response.
Damanhouri
Z A
ZA
Department of Pharmacology, Faculty of Medicine & Allied Sciences, King Abdulaziz University, P.O. Box 9029, Jeddah 21413, Saudi Arabia.
Tayeb
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O
D000818:Animals; D001831:Body Temperature; D002217:Carbachol / Q000494:pharmacology*; D018679:Cholinergic Agonists / Q000494:pharmacology*; D017077:Culture Media, Conditioned; D004305:Dose-Response Relationship, Drug; D004573:Electrolytes / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D005947:Glucose / Q000032:analysis; D006360:Heat-Shock Proteins / Q000737:chemistry*; D018869:Heat-Shock Response / Q000502:physiology*; D007082:Ileum / Q000187:drug effects / Q000502:physiology; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology*; D051381:Rats
D018679:Cholinergic Agonists; D017077:Culture Media, Conditioned; D004573:Electrolytes; D006360:Heat-Shock Proteins; D002217:Carbachol; D005947:Glucose