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Arteriole Diameter (arteriole + diameter)
Selected AbstractsRegression of Alterations in Retinal Microcirculation Following Treatment for Arterial HypertensionJOURNAL OF CLINICAL HYPERTENSION, Issue 8 2006Antonio Pose-Reino MD Evaluation of early hypertension-related alterations in retinal microcirculation has been subjective and poorly reproducible. The authors recently described a semiautomatic computerized system for evaluation of the calibre of retinal blood vessels that has shown very good reproducibility. In the study, this system was used to measure the calibres of retinal arterioles and veins, and their ratio, in a group of 51 hypertensive outpatients before and after 6 months of treatment with losartan or, if required for satisfactory blood pressure control, losartan plus hydrochlorothiazide. Mean retinal arteriole diameter increased from 0.0842±0.003 mm to 0.0847±0.003 mm (p=0.001). Arteriovenous ratio increased from 0.753±0.03 to 0.756±0.03 (p=0.005). This observation suggests regression of early hypertension-related alterations in retinal microcirculation after 6 months of antihypertensive treatment. [source] Response of retinal arteriole diameter to increased blood pressure during acute hyperglycaemiaACTA OPHTHALMOLOGICA, Issue 3 2007Peter Jeppesen Abstract. Purpose:, To study retinal response in terms of arteriole diameter and retinal thickness secondary to an increase in arterial blood pressure during acute hyperglycaemia. Methods:, In a randomized, double-blinded, cross-over study, nine healthy persons were subjected to clamping of blood glucose to either 5 mmol/l or 15 mmol/l using somatostatin to control endogenous insulin secretion. The response of retinal arterioles in terms of diameter as determined with the retinal vessel analyser (RVA) and retinal thickness as assessed by optical coherence tomography (OCT) were measured after an increase in arterial blood pressure induced by isometric exercise. Arterial feeding pressure in the eye was assessed from the ophthalmic artery pressure and pulse amplitude measured by ophthalmodynamometry. Results:, Isometric exercise induced a significant increase in mean arterial blood pressure and a significant contraction of the retinal arterioles. An acute increase in blood glucose from 5 mmol/l to 15 mmol/l did not affect either the diameter of retinal vessels or retinal thickness. Conclusions:, Acute hyperglycaemia per se does not change isometric exercise-induced retinal arteriolar contraction. Metabolic factors other than blood glucose are suspected to be involved in the impairment of retinal autoregulation as seen in hyperglycaemia induced by oral glucose intake. [source] Effect of HTK on the microcirculation in the rat cremaster muscle during warm ischemia and reperfusionMICROSURGERY, Issue 2 2005Jacqueline Bastiaanse M.D. Histidine-tryptophan-ketoglutarate (HTK) preserves rat muscle function during cold storage. We examined the effect of HTK perfusion on preservation of microvascular function during 4 h of warm ischemia and subsequent reperfusion (I/R) in the rat cremaster muscle. Leukocyte-endothelium interactions, capillary perfusion, and arteriole diameters were quantified prior to HTK-perfusion and/or ischemia, and at 0, 1, and 2 h after restoration of blood flow. In all groups, the number of rolling leukocytes increased with time, whereas I/R induced a slight increase in leukocyte adhesion. After ischemia, capillary perfusion rapidly recovered to about 50% and returned to near normal (90%) after 2 h. HTK at 22°C did not affect the assessed microcirculation variables, whereas HTK at 4°C reduced leukocyte rolling, but not adhesion. Therefore, microvascular function of HTK-perfused muscles was not better preserved during warm I/R than that of nonperfused muscles. Contrary to other preservation solutions, HTK perfusion in itself was not detrimental to the microcirculation. © 2005 Wiley-Liss, Inc. Microsurgery 25:174,180, 2005. [source] | ||||||||||