The renin-angiotensin system in the endocrine pancreas.
Experimental data suggest that a tissue renin-angiotensin system is present in the pancreatic islets of several species, including man. However, the physiological role for this local renin-angiotensin system remains largely unknown. In vitro findings argue against a direct effect of angiotensin II on alpha- and beta-cells. In contrast, when the influence of angiotensin II on the pancreatic islets has been evaluated in the presence of an intact vascular system either in vivo or in the perfused pancreas, a suppression of insulin release has been observed, also in man. These discrepancies may be explained by the profound effects of the renin-angiotensin system on pancreatic islet blood perfusion. Alterations in the systemic renin-angiotensin system and an increased vascular sensitivity for its components have been observed in diabetes mellitus and hypertension. Whether changes occur also in the pancreatic islet renin-angiotensin system during these conditions remains unknown. Future research may help to provide an answer to this question, and to elucidate to what extent the renin-angiotensin system may contribute to beta-cell dysfunction in these diseases.
Carlsson
P O
PO
Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden. per-ola.carlsson@medcellbiol.uu.se
D000818:Animals; D003920:Diabetes Mellitus / Q000503:physiopathology; D006801:Humans; D007515:Islets of Langerhans / Q000502:physiology* / Q000503:physiopathology; D012084:Renin-Angiotensin System / Q000502:physiology*