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The effect of amitraz, a formamidine insecticide, on in vitro intestinal contractions was studied in teh transmurally-stimulated guinea-pig ileum. An electrical stimulation (with 80 V/0.5 msec/0.1 Hz shown on the dial of the stimulator) caused the ileum to contract presumably via the release of acetylcholine. Amitraz (10(-7) to 10(-6) M) produced a dose-dependent inhibition of these transmurally-stimulated contractions. This effect of amitraz was blocked and reversed by idazoxan (10(-6) M), an alpha 2-adrenoceptor antagonist, but was not prevented by prazosin (10(-6) M), an alpha 1-adrenoceptor antagonist. These results suggest that alpha 2-adrenoceptors mediate the effects of amitraz on the transmurally-stimulated guinea-pig ileum. The results also suggest that amitraz decreases intestinal contraction by activating the alpha 2-adrenoceptors in the myenteric (Auerbach's) plexus, thus inhibiting parasympathetic tone.
W H Hsu, and
R N Shaw, and
D D Schaffer, and
M H Crump, and
M H Greer
May 1983,
The Journal of pharmacology and experimental therapeutics,
W H Hsu, and
R N Shaw, and
D D Schaffer, and
M H Crump, and
M H Greer
December 1986,
Gastroenterology,
W H Hsu, and
R N Shaw, and
D D Schaffer, and
M H Crump, and
M H Greer
August 1980,
European journal of pharmacology,
W H Hsu, and
R N Shaw, and
D D Schaffer, and
M H Crump, and
M H Greer
January 1988,
European journal of clinical pharmacology,
W H Hsu, and
R N Shaw, and
D D Schaffer, and
M H Crump, and
M H Greer
April 1980,
Journal of neurochemistry,
W H Hsu, and
R N Shaw, and
D D Schaffer, and
M H Crump, and
M H Greer
January 1991,
Comparative biochemistry and physiology. C, Comparative pharmacology and toxicology,
W H Hsu, and
R N Shaw, and
D D Schaffer, and
M H Crump, and
M H Greer
October 1969,
Indian journal of experimental biology,
W H Hsu, and
R N Shaw, and
D D Schaffer, and
M H Crump, and
M H Greer
December 1991,
Surgery,
W H Hsu, and
R N Shaw, and
D D Schaffer, and
M H Crump, and
M H Greer
March 1993,
Gastroenterology,
W H Hsu, and
R N Shaw, and
D D Schaffer, and
M H Crump, and
M H Greer
January 1972,
Microbios,
