TY - JOUR
T1 - Effects of adrenomedullin on ocular hemodynamic parameters in the choroid and the ophthalmic artery
AU - Dorner, Guido T.
AU - Garhöfer, Gerhard
AU - Huemer, Karl Heinz
AU - Golestani, Elisabeth
AU - Zawinka, Claudia
AU - Schmetterer, Leopold
AU - Wolzt, Michael
PY - 2003/9/1
Y1 - 2003/9/1
N2 - PURPOSE. Adrenomedullin acts as a vasodilator and may play a role in inflammatory processes in the eye. This study was designed to determine whether nitric oxide formation is involved in the response to adrenomedullin in the ocular vasculature in vivo. METHODS. The effects of systemic intravenous adrenomedullin (3.2-16.0 pmol/[kg · min])) on choroidal blood flow were assessed by measurement of fundus pulsation amplitude and laser Doppler flow in the macula, and on blood flow in the ophthalmic artery by ultrasound Doppler flow in pilot studies (n = 7). Subsequently, in a double-blind randomized placebo-controlled crossover study in eight healthy male subjects the effects of 12.8 pmol/(kg · min) adrenomedullin on ocular and systemic hemodynamics were investigated. Adrenomedullin was co-infused with the nitric oxide synthase inhibitor NG-monomethyl-L-arginine (3 mg/kg bolus and 30 μg/[kg · min] continuous intravenous infusion) or vehicle control on separate study days. RESULTS. Adrenomedullin dose dependently increased choroidal blood flow and flow velocity in the ophthalmic artery. N G-monomethyl-L-arginine reduced the effect of adrenomedullin on fundus pulsation amplitude, but did not alter the flow response in the ophthalmic artery. Systemic hemodynamics were unaffected by adrenomedullin infusion. CONCLUSIONS. Ocular blood flow is sensitive to changes in adrenomedullin concentrations. The acute vasodilator effects of adrenomedullin are nitric oxide-dependent in the choroid, but not in the ophthalmic artery.
AB - PURPOSE. Adrenomedullin acts as a vasodilator and may play a role in inflammatory processes in the eye. This study was designed to determine whether nitric oxide formation is involved in the response to adrenomedullin in the ocular vasculature in vivo. METHODS. The effects of systemic intravenous adrenomedullin (3.2-16.0 pmol/[kg · min])) on choroidal blood flow were assessed by measurement of fundus pulsation amplitude and laser Doppler flow in the macula, and on blood flow in the ophthalmic artery by ultrasound Doppler flow in pilot studies (n = 7). Subsequently, in a double-blind randomized placebo-controlled crossover study in eight healthy male subjects the effects of 12.8 pmol/(kg · min) adrenomedullin on ocular and systemic hemodynamics were investigated. Adrenomedullin was co-infused with the nitric oxide synthase inhibitor NG-monomethyl-L-arginine (3 mg/kg bolus and 30 μg/[kg · min] continuous intravenous infusion) or vehicle control on separate study days. RESULTS. Adrenomedullin dose dependently increased choroidal blood flow and flow velocity in the ophthalmic artery. N G-monomethyl-L-arginine reduced the effect of adrenomedullin on fundus pulsation amplitude, but did not alter the flow response in the ophthalmic artery. Systemic hemodynamics were unaffected by adrenomedullin infusion. CONCLUSIONS. Ocular blood flow is sensitive to changes in adrenomedullin concentrations. The acute vasodilator effects of adrenomedullin are nitric oxide-dependent in the choroid, but not in the ophthalmic artery.
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U2 - 10.1167/iovs.02-0855
DO - 10.1167/iovs.02-0855
M3 - Article
C2 - 12939313
AN - SCOPUS:0042362027
SN - 0146-0404
VL - 44
SP - 3947
EP - 3951
JO - Investigative Ophthalmology and Visual Science
JF - Investigative Ophthalmology and Visual Science
IS - 9
ER -