Abstract: Objective This study was to investigate the expression of angiotensin -converting enzyme 2(ACE2) in rat exocrine and endocrine tissue of pancreas and compare its expression level to other visceral tissues. Methods The expressions of ACE2 in rats visceral organs (pancreas, lung, liver, kidney, heart, intestinal tract, bladder and spleen) were detected by immunohistochemistry and reverse transcriptase polymerase chain reaction (RT-PCR). Results ACE2 was positively expressed in all the studied tissues, including pancreas, heart, liver, kidney, lung,spleen, duodenum, ileum and bladder. The expression of ACE2 mRNA was detected in whole pancreas and ACE2 protein was detected in both endocrine tissue and exocrine tissue of rat pancreas, while in the endocrine tissue ACE2 protein was expressed much weaker. Conclusions ACE2 was comprehensively present in rat visceral organs, providing possible routes of entry for the SARS-CoV. Our data demonstrated a tissue specific pattern of ACE2 expression in rat pancreas and this indicated ACE2 may be present in islet of pancreas of human, which may cause the elevation of blood glucose levels in SARS patients. Since ACE2 works as a negative regulator of the angiotensin system, the expression of ACE2 protein in endocrine tissue of pancreas may give us more clue for the treatment of diabetes.

Key words: angiotensin-converting enzyme 2, SARS-CoV, S protein, pancreas, angiotensin-converting enzyme 2 SARS-CoV S protein pancreas