title: Inhibition of caffeine contractures of slow rat muscles by urea and its derivatives.
abstract: Contractures induced by rapid cooling of rat soleus muscles in the presence of low concentrations of caffeine (2-3 mmol.l-1) have been studied. Urea, methylurea and 1,3-dimethylurea inhibit reversibly these contractures as well as caffeine contractures (20 mmol.l-1, 30 degrees C) but do not affect twitches. This finding leads support to the idea of the existence of different mechanisms activating contraction in response to caffeine action or deplorization.
mesh_terms: D000818:Animals; D002110:Caffeine / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D003864:Depression, Chemical; D008782:Methylurea Compounds / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects*; D009132:Muscles / Q000502:physiology; D051381:Rats; D014508:Urea / Q000494:pharmacology*
chemical_list: D008782:Methylurea Compounds; D002110:Caffeine; D014508:Urea