Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

AIMS/HYPOTHESIS: This study aimed to identify the expression of angiotensin II receptors in isolated human islets and beta cells and to examine the functional consequences of their activation. MATERIALS AND METHODS: Single-cell RT-PCR was used to identify whether human islet cells express mRNA for type 1 angiotensin II receptors (AT(1)), and western blotting was used to determine AT(1) protein expression by human islets and MIN6 beta cells. We measured changes in intracellular calcium by microfluorimetry using Fura 2-loaded MIN6 cells and human islet cells. Dynamic insulin secretory responses were determined by RIA following perifusion of human islets and MIN6 cells. RESULTS: Human islets expressed mRNAs for both the angiotensin precursor, angiotensinogen, and for angiotensin-converting enzyme. In addition, human and mouse beta cells expressed AT(1). These were functionally coupled to increases in intracellular calcium, which occurred at least in part through phospholipase-C-sensitive mechanisms and calcium influx through voltage-operated calcium channels. Short-term exposure of human islets and MIN6 cells to angiotensin II caused a rapid, short-lived initiation of insulin secretion at 2 mmol/l glucose and potentiation of insulin secretion induced by glucose (at 8 and 16.7 mmol/l). CONCLUSIONS/INTERPRETATION: These data demonstrate that the AT(1) is expressed by beta cells and that angiotensin II effects a short-lived and direct stimulation of human and mouse beta cells to promote insulin secretion, most probably through elevations in intracellular calcium. Locally produced angiotensin II may be important in regulating a coordinated insulin secretory response from beta cells.

Original publication




Journal article



Publication Date





321 - 331


Angiotensin Amide, Angiotensin II, Angiotensinogen, Animals, Blotting, Western, Calcium, Cell Line, Cells, Cultured, Fluorometry, Gene Expression Regulation, Glucose, Humans, Imidazoles, Insulin, Insulin Secretion, Insulin-Secreting Cells, Islets of Langerhans, Mice, Nifedipine, Peptidyl-Dipeptidase A, Pyridines, RNA, Messenger, Receptors, Angiotensin, Reverse Transcriptase Polymerase Chain Reaction, Saralasin