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Turkish Journal of Veterinary & Animal Sciences

DOI

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Abstract

In this study, 18 adult guinea pigs, weighing 300-450 g, were divided into three equal groups, and their small intestinal segments (proximal and distal ileum) were removed and kept in vitro in an isolated organ bath in order to record the responses mainly produced by lead and acetylcholine. For the tissues of the first group, the noncumulative concentration-response curves of lead obtained were compared by applications at concentrations ranging from 3x10^{-8} M to 3x10^{-5} M alone, in the presence of verapamil (3x10^{-5} M) and in Ca^{++} free solution. In the second group, the responses to lead at the same concentrations in the presence of acetylcholine (3x10^{-5} M), and in the third group, the responses to acetylcholine at the concentration of 3x10^{-5} M alone and in the presence of lead at the same concentrations were obtained, and comparisons were made among these three groups. The noncumulative concentration-response curves showed that in both the proximal and distal ileum of guinea pigs, lead created contractions at doses ranging from 3x10^{-8} M to 1x10^{-5} M, and relaxation at a concentration of 3x10^{-5} M, although the amplitudes of both contractions and relaxation were different for the two tissues. Maximum contractions were seen at a concentration of 3x10^{-7} M, and Ca^{++} played an important role in these responses induced by lead in both tissues. In the proximal ileum, there were increasing trends at all concentrations of lead-induced responses in the presence of acetylcholine; however, the only significant difference (p

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