TY - JOUR
T1 - Effects of dopamine on ciliary blood flow, aqueous production, and intraocular pressure in rabbits
AU - Reitsamer, Herbert A.
AU - Kiel, Jeffrey W.
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2002
Y1 - 2002
N2 - PURPOSE. Dopamine is a known modulator of cardiovascular function and intraocular pressure (IOP). In this study, the authors investigate the dose-dependent effects of dopamine on IOP, ciliary, hemodynamics, and aqueous production in anesthetized rabbits to test the hypothesis that aqueous production becomes blood-flow- dependent if ciliary perfusion declines below some unknown critical level. METHODS. Two protocols were performed. In the first protocol, mean arterial pressure (MAP) and IOP were measured by direct cannulation, and ciliary, blood flow was measured transsclerally by laser Doppler flowmetry, while MAP was varied mechanically over a wide range before and during intravenous dopamine infusion (40 μg/min, n = 8; 80 μg/min, n = 10; 600 μg/min, n = 7; 1800μg/min, n = 5). In the second protocol, MAP and IOP were measured by direct cannulation, and aqueous flow was measured by fiuorophotometry, before and during intravenous dopamine infusion (40 μg/min, n = 8; 600 μg/min, n = 11). RESULTS. The low infusion rate shifted the ciliary, pressure flow curves upward and increased aqueous production (40 μg/ min), whereas the higher infusion rates shifted the pressure flow curves downward (600 and 1800μg/min) and decreased aqueous production (600μg/min). All infusion rates decreased IOP. CONCLUSIONS. Dopamine causes dose-dependent, parallel changes in ciliary blood flow and aqueous production, with ciliary vasodilation and secretory stimulation at the lowest infusion rate and vasoconstriction and secretory inhibition at higher infusion rates. Dopamine also significantly lowers IOP.
AB - PURPOSE. Dopamine is a known modulator of cardiovascular function and intraocular pressure (IOP). In this study, the authors investigate the dose-dependent effects of dopamine on IOP, ciliary, hemodynamics, and aqueous production in anesthetized rabbits to test the hypothesis that aqueous production becomes blood-flow- dependent if ciliary perfusion declines below some unknown critical level. METHODS. Two protocols were performed. In the first protocol, mean arterial pressure (MAP) and IOP were measured by direct cannulation, and ciliary, blood flow was measured transsclerally by laser Doppler flowmetry, while MAP was varied mechanically over a wide range before and during intravenous dopamine infusion (40 μg/min, n = 8; 80 μg/min, n = 10; 600 μg/min, n = 7; 1800μg/min, n = 5). In the second protocol, MAP and IOP were measured by direct cannulation, and aqueous flow was measured by fiuorophotometry, before and during intravenous dopamine infusion (40 μg/min, n = 8; 600 μg/min, n = 11). RESULTS. The low infusion rate shifted the ciliary, pressure flow curves upward and increased aqueous production (40 μg/ min), whereas the higher infusion rates shifted the pressure flow curves downward (600 and 1800μg/min) and decreased aqueous production (600μg/min). All infusion rates decreased IOP. CONCLUSIONS. Dopamine causes dose-dependent, parallel changes in ciliary blood flow and aqueous production, with ciliary vasodilation and secretory stimulation at the lowest infusion rate and vasoconstriction and secretory inhibition at higher infusion rates. Dopamine also significantly lowers IOP.
UR - http://www.scopus.com/inward/record.url?scp=0036319774&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0036319774&partnerID=8YFLogxK
M3 - Article
C2 - 12147605
AN - SCOPUS:0036319774
VL - 43
SP - 2697
EP - 2703
JO - Investigative Ophthalmology and Visual Science
JF - Investigative Ophthalmology and Visual Science
SN - 0146-0404
IS - 8
ER -