![]() |
|
|
GW Gullikson, RF Loeffler and MA Virina
Gastrointestinal Diseases Research Department, G. D. Searle Co., Skokie, Illinois.
Drugs that enhance gastrointestinal motility include the benzamide drugs metoclopramide, cisapride and renzapride (BRL-24924). Because these agents also are serotonin-3 (5-HT3) receptor antagonists, which can promote gastric emptying in some species, the motor-stimulating properties of benzamide agents may be due to this mechanism. Metoclopramide (0.3-3.0 mg/kg i.v.), cisapride (0.03-1.0 mg/kg i.v.) and BRL-24924 (0.01-0.1 mg/kg i.v.) were evaluated for their relative motility-stimulating and 5-HT3 receptor antagonist activities in conscious dogs and were compared with selective 5-HT3 antagonist antiemetic compounds ICS-205-930, (3 alpha-tropanyl)1-H-indole-3- carboxylic acid ester and granisetron (BRL-43694). Gastric antral contractions and intestinal myoelectric motility were determined in response to drugs, as were their effects on solid and liquid emptying in a gamma scintigraphic model of gastroparesis. 5-HT3 receptor antagonist potency was examined by deriving ED50 values for inhibition of cisplatin emesis. All drugs were 5-HT3 antagonists as they blocked cisplatin emesis with relative potencies of BRL-43694 = ICS-205-930 greater than BRL-24924 greater than cisapride = metoclopramide. The order of potency for stimulating fasted dog antral contractile activity, however, was BRL-24924 = cisapride greater than metoclopramide greater than ICS-205-930 = BRL-43694. Maximally effective doses of BRL-24924 (0.1 mg/kg i.v.) and cisapride (0.67 mg/kg i.v.) in the antrum also stimulated intestinal myoelectrical activity, whereas ICS-205-930 (0.5 and 2.0 mg/kg i.v.) was not active.(ABSTRACT TRUNCATED AT 250 WORDS)
This article has been cited by other articles:
![]() |
T. Tanaka, A. Mizumoto, E. Mochiki, H. Suzuki, Z. Itoh, and S. Omura Effects of EM574 and Cisapride on Gastric Contractile and Emptying Activity in Normal and Drug-Induced Gastroparesis in Dogs J. Pharmacol. Exp. Ther., November 1, 1998; 287(2): 712 - 719. [Abstract] [Full Text] |
||||
![]() |
C. W. Song, K. Y. Lee, C. D. Kim, T-M. Chang, and W. Y. Chey J. Pharmacol. Exp. Ther., June 1, 1997; 281(3): 1312 - 1316. [Abstract] [Full Text] |
||||