A comparative study of the effects of ethanol, acetylcholine and adrenaline on various parameters of intestinal contractions of rabbit.
A comparative study was carried out to observe the effects of ethanol, acetylcholine and adrenaline on various parameters of the contraction cycle of rabbit intestine. Acetylcholine and adrenaline were used in concentrations of 10(-3), either alone or in combination with absolute ethanol. The results showed that ethanol and acetylcholine had no effect on the rate of intestinal contractions while adrenaline increased it significantly. However, all these drugs decreased the active tension of the contracting intestine, the decrease being minimum for ethanol, moderate for acetylcholine and maximum for adrenaline. On the contrary, a small transient decrease in resting tension was produced by ethanol and this occurred at a very fast rate while adrenaline produced a marked decrease in this parameter, its rate being 6-10 times slower. Ethanol and acetylcholine were also found to increase the resting tension, it being 2 times greater and occurring at a faster rate with acetylcholine. It is suggested that these drugs produce their effect by altering resting membrane potential, Ca++ and other ion fluxes.
Nasreen
R
R
Department of Pharmacology, Faculty of Pharmacy, University of Karachi, Karachi-75270, Pakistan.
Shaikh
H A
HA
Ali
S T
ST
Ahmad
S I
SI