PURPOSE: There is controversy regarding the nervous control of retinal blood vessels in humans. Most in vitro studies indicate that the intraocular part of the central retinal artery lacks autonomic innervation. We investigated the response of retinal vessels to isometric exercise during blockade of beta-receptors (propranolol) or muscarinic receptors (atropine). METHODS:Twelve healthy subjects performed squatting for 6 min during infusion of either propranolol atropine or placebo. Blood pressure and pulse rate were measured non-invasively. Retinal vessel diameters were measured continuously using the Zeiss Retinal Vessel Analyser. RESULTS: Squatting induced a significant increase in blood pressure and pulse rate, which was paralleled by a decrease in retinal vein and artery diameters. Atropine did not change the retinal vessel response to isometric exercise. Propranolol significantly blunted the exercise-induced vasoconstriction in retinal arteries. CONCLUSION: This result likely indicates propranolol-evoked vasoconstriction in the extraocular parts of the central retinal artery during isometric exercise. Copyright 2001 S. Karger AG, Basel
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PURPOSE: There is controversy regarding the nervous control of retinal blood vessels in humans. Most in vitro studies indicate that the intraocular part of the central retinal artery lacks autonomic innervation. We investigated the response of retinal vessels to isometric exercise during blockade of beta-receptors (propranolol) or muscarinic receptors (atropine). METHODS: Twelve healthy subjects performed squatting for 6 min during infusion of either propranolol atropine or placebo. Blood pressure and pulse rate were measured non-invasively. Retinal vessel diameters were measured continuously using the Zeiss Retinal Vessel Analyser. RESULTS: Squatting induced a significant increase in blood pressure and pulse rate, which was paralleled by a decrease in retinal vein and artery diameters. Atropine did not change the retinal vessel response to isometric exercise. Propranolol significantly blunted the exercise-induced vasoconstriction in retinal arteries. CONCLUSION: This result likely indicates propranolol-evoked vasoconstriction in the extraocular parts of the central retinal artery during isometric exercise. Copyright 2001 S. Karger AG, Basel
Authors: Adrian Gericke; Jan J Sniatecki; Evgeny Goloborodko; Andreas Steege; Olga Zavaritskaya; Jan M Vetter; Franz H Grus; Andreas Patzak; Jürgen Wess; Norbert Pfeiffer Journal: Invest Ophthalmol Vis Sci Date: 2011-09-27 Impact factor: 4.799
Authors: Adrian Gericke; Veronique G A Mayer; Andreas Steege; Andreas Patzak; Ulrike Neumann; Franz H Grus; Stephanie C Joachim; Lars Choritz; Jürgen Wess; Norbert Pfeiffer Journal: Invest Ophthalmol Vis Sci Date: 2009-04-30 Impact factor: 4.799