الفهرس 
ACKNOWLEDGMENT
IntroductionOnly 14 pages are availabe for public view
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Abstract
This work was done on isolated segments of the gut including the lower esophagus , gastric fundus and antral strips , jejunal and colonic segments. The following four groups of experiments were done on each segment of the gut: • Group I experiments: to study the effect of ghrelin (10-8M) on the basal motility of GIT. This group of experiments was done by the addition of ghrelin after recording of the basal motility pattern. • Group II experiments : to study the effect of ghrelin (10-8M) on the motility of GIT after adding Ach (10-5M) , atropine sulphate (10-6M) , phentolamine (10-6M) , or propranolol hydrochloride (10-6M). The basal motility was recorded then Ach , atropine sulphate , phentolamine or propranolol hydrochloride was added after that ghrelin was added all in the previous concentrations mentioned above. • Group III experiments : to study the effect of ghrelin (10-8M) on the motility of GIT after adding verapamil hydrochloride (10-6M). • Group IV experiments : to study the effect of ghrelin (10-8M) on the motility of GIT after adding sodium nitroprosside (10-5M) or L-NAME (10-4M). The results showed that ghrelin produced a significant decrease in the contraction of the fundus of the stomach and a significant increase in the contraction of other segments Ghrelin after Ach caused more significant increase in the tone and amplitude of jejunal and colonic contractions , and caused also more significant increase in tone of esophageal and antral contractions as compared with the affect of Ach alone . In the fundus ghrelin caused significant decrease in the amplitude and the tone of Ach stimulated contractions. Ghrelin after atropine showed insignificant change in the tone and amplitude of all segments except the fundus. While addition of phentolamine or propranolol hydrochloride befor ghrelin did not cause any change in the ghrelin effects in all segments of the gut However , addition of verapamil before ghrelin completely abolished its stimulatory effects on the contractions of different segments of the gut. L-NAME in the fundus showed a significant increase in the tone and amplitude of fundic contractions and prevented the relaxing effects of ghrelin in the fundus. In conclusion that : 1- Ghrelin induces a stimulatory effect on the motility of different parts of the gut except on the funds it has a relaxing effect. 2- The stimulatory effects of ghrelin is mediated mainly through activation of cholinergic neurons in the gut wall. 3- The inhibitory effects of ghrelin in the fundus is mediated through NO release from the nitrergic neurons. 4- Ca+2 is essential for the stimulatory effects of ghrelin on the GIT.