کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4012201 1261183 2008 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Retinal arteriolar and capillary vascular reactivity in response to isoxic hypercapnia
موضوعات مرتبط
علوم زیستی و بیوفناوری ایمنی شناسی و میکروب شناسی ایمونولوژی و میکروب شناسی (عمومی)
پیش نمایش صفحه اول مقاله
Retinal arteriolar and capillary vascular reactivity in response to isoxic hypercapnia
چکیده انگلیسی

The aim of the study was to compare the magnitude of vascular reactivity of the retinal arterioles in terms of percentage change to that of the retinal capillaries using a novel, standardized methodology to provoke isoxic hypercapnia. Ten healthy subjects (mean age 25 years, range 21–31) were recruited. Subjects attended a single visit comprising two study sessions separated by 30 min. Subjects were fitted with a sequential re-breathing circuit connected to a computer-controlled gas blender. Each session consisted of breathing at rest for 10 min (baseline), increase of PETCO2 (maximum partial pressure of CO2 during expiration) by 15% above baseline whilst maintaining isoxia for 20 min, and returning to baseline conditions for 10 min. Retinal hemodynamic measurements were performed using the Canon Laser Blood Flowmeter and the Heidelberg Retina Flowmeter in random order across sessions. Retinal arteriolar diameter, blood velocity and flow increased by 3.3%, 16.9% and 24.9% (p < 0.001), respectively, during isoxic hypercapnia. There was also an increase of capillary blood flow of 34.8%, 21.6%, 24.9% (p ≤ 0.006) at the optic nerve head neuroretinal rim, nasal macula and fovea, respectively. The coefficient of repeatability (COR) was 5% of the average PETCO2 both at baseline and during isoxic hypercapnia and was 10% and 7% of the average PETO2 (minimum partial pressure of oxygen at end exhalation), respectively. The overall magnitude of retinal capillary vascular reactivity was equivalent to the arteriolar vascular reactivity with respect to percentage change of flow. The magnitude of isoxic hypercapnia was repeatable.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Experimental Eye Research - Volume 87, Issue 6, 10 December 2008, Pages 535–542
نویسندگان
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