Expression of ghrelin mRNA in duodenum and jejunum of weaning piglets and the role of endogenous somatostatin

To study the expression of ghrelin mRNA in small intestinal tissue of weaning piglets and to investigate the effect of ghrelin on intestinal growth and functional development,to study the role of endogenous somatostatins as well.18 litters of newborn piglets were divided randomly to control and treatment groups.From 12 days of age,piglets in treatment group were fed starter diet supplemented with 120 mg/kg cysteamine to deplete endogenous somatostatin(SS).Piglets were weaned at 35 days of age(d35) in both groups.6 piglets from each group were slaughtered on 28,35,38,42 and 45 d,respectively.A semiquantitative RT-PCR was applied to detect the level of ghrelin mRNA in duodenum and jejunum tissues with 18S rRNA as an internal standard,and to intestigate the effects of endocrine SS on ghrelin mRNA expression.The results were as follows:(1) Ghrelin mRNA expression in duodenum exhibited a trend of decrease from 28 d to 45 d,ghrelin mRNA expression was significant lower on 38,45 d than on 28,35 d;Cysteamine increased thd level of ghrelin mRNA expression and the differences were significant only on 45 d.(2) Ghrelin mRNA expression in jejunum exhibited a significant lower level on 38 d,42 d and 45 d than other days(P0.05);On 38 d,cysteamine increased the level of ghrelin mRNA expression significantly.These results suggested ghrelin mRNA is expressed in an age dependent manner in jejunum and duodenum;and cysteamine can promeote the ghrelin expression by depleting the endogenous somatostatin.