Autoregulation of Human Retinal Arterioles during Long-time Ergometric Stress Period
Bartke T. U.1, Fischer F. 1, Hilberg T.2, End S.2, Blum M.3, Strobel J.1
1Augenklinik, 2Lehrstuhl für Sportmedizin, Friedrich-Schiller-Universität Jena; 3Augenklinik, Helios Klinikum Erfurt
Purpose: The Retinal-Vessel-Analyzer (RVA) offers the unique opportunity of a non-invasive online measurements of retinal vessel diameters and allowed for the first time non-invasive analyses of Bayliss effect on human retinal arterioles. This study investigates the autoregulation of retinal arterioles on condition of standardized long-time dynamic stress period.
Method: In cooperation with the Institute of Sports Science we quantified the Individual Anaerobic Threshold (IAS) in each volunteer in order to standardize the effect of physical exercise. After a rest period 25 healthy male volunteers aged 20 up to 44 years were exposed to ergometric exercise for 45 minutes at a level of 90% of IAS followed by a recovery of six minutes. Continuous measurement of retinal arterioles was performed by means of RVA. Mean arterial blood pressure (MAP), pulse, and lactic acid were measured every three minutes.
Results: Lactic acid and blood pressure remained at a considerably high level whereas heart rate continuously rose during exercise. An initial highly significant vasoconstriction was followed by a period of smooth vasodilatation swinging to a level below baseline vessel diameter. After approxima
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