PT - JOURNAL ARTICLE AU - Jack W. Miller AU - Anthony Kisley AU - William J. Murray TI - THE EFFECTS OF RELAXIN-CONTAINING OVARIAN EXTRACTS ON VARIOUS TYPES OF SMOOTH MUSCLE DP - 1957 Aug 01 TA - Journal of Pharmacology and Experimental Therapeutics PG - 426--437 VI - 120 IP - 4 4099 - http://jpet.aspetjournals.org/content/120/4/426.short 4100 - http://jpet.aspetjournals.org/content/120/4/426.full SO - J Pharmacol Exp Ther1957 Aug 01; 120 AB - The effects of ovarian extracts containing relaxin on various types of smooth muscle have been investigated. Administration of the extracts to dogs produced hypotension, bradycardia and inhibition of ureteral motility; tachyphylaxis developed to these actions. A component in the extracts caused the release of histamine in quantities sufficient to account for the hypotension. The extracts inhibited the spontaneous uterine motility of the rat but not that of the rabbit or human (in vitro). Tachyphylaxis developed to the uterine inhibitory action in vitro and in vivo. The component which produced hypotension differed from the factor which inhibited the uterus in not being inactivated by pepsin. The results of these studies have been discussed in relation to the effects of relaxin-containing extracts in man.