Tissue-specific in vivo inhibition of DNase I gene expression by somatostatin

Administration of somatostatin to rats induced a transient reduction of ser um levels of deoxyribonuclease I (DNase I) activity in a dose-dependent man ner, followed by a substantial decrease of DNase I activity in the lower gu t. Activity in the parotid gland, liver, and kidney did not change. Real-ti me PCR analysis of the DNase I gene transcript in ileum indicated that the decrease was due to down-regulation of gene expression. Based on these resp onses, rat tissues expressing DNase I could be classified into two types, s omatostatin-sensitive and somatostatin-resistant, and the level of DNase I activity in the lower gut seems to be controlled by somatostatin. (C) 2001 Academic Press.