ISSN:
1432-0428
Keywords:
Key words Retinal microvascular pericytes, hyperglycaemia, endothelin-1, inositol (1,4,5) trisphosphate.
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The effect of simulated hyperglycaemia on bovine retinal pericytes was studied following culture of these cells for 10 days under normal (5 mmol/l) and elevated (25 mmol/l) glucose conditions in the absence of endothelial cells. Pericytes cultured under high ambient glucose exhibited both a delayed and reduced contractile response following stimulation with endothelin-1. Stimulation with 10−7 mol/l endothelin-1 for 30 s caused significant contraction in cells grown in both 5 mmol/l and 25 mmol/l glucose. The former also contracted significantly with 10−8 mol/l endothelin-1. Further, at all concentrations tested, statistical comparison of the time course of contraction showed a significant difference (p〈0.02) in the reduction of planimetric surface area between the two cell groups. Since neither binding of endothelin-1 nor the number of receptors for this peptide were significantly different (p〉0.1) between bovine retinal pericytes grown for 10 days under normo- or hyperglycaemic conditions, it became apparent that the altered contractility in bovine retinal pericytes following culture in high glucose must be due to post-binding intracellular disturbance(s). Indeed, both basal and 15 s post-stimulation with 10−8 mol/l endothelin-1, levels of inositol trisphosphate were significantly reduced (p〈0.05 and p〈0.02, respectively) in pericytes cultured for 10 days in 25 mmol/l glucose. These results show that endothelial-independent alterations in contractility of pericytes occur when they are grown in conditions which simulate hyperglycaemia. The results also suggest that the observed attenuation in response to endothelin-1 stimulation evident in pericytes grown under simulated hyperglycaemic conditions is not due to alterations in peptide binding. [Diabetologia (1994) 37: 36–42]
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s001250050069
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