[Optic nerve head and choroidal circulation measured by laser Doppler flowmetry in response to intravenous administration of noradrenaline].
We investigated the change of optic nerve head blood flow (ONHBF) and choroidal blood flow (CBF) in response to noradrenaline (NA) intravenously administered in anesthetized cats. NA (0.03, 0.1, 0.3 micrograms/kg/min) was injected 5 minutes continuously via the femoral vein. The relative blood flow and systemic blood pressure were continuously measured before and after NA administration with fundus camera-based laser Doppler flowmetry. Systemic blood pressure increased by 6%, 42% and 48% according to the dose. The changes in ONHBF after NA administration were -1.4 +/- 3.5% (mean +/- standard deviation) with 0.03 micrograms/kg/min, 2.4 +/- 6.9% with 0.1 micrograms/kg/min, -2.2 +/- 4.4% with 0.3 micrograms/kg/min, respectively. It did not change significantly despite doses of NA. CBF did not change significantly with 0.03 micrograms/kg/min. CBF increased significantly by 62.7 +/- 65.4% with 0.1 micrograms/kg/min, and 80.4 +/- 73.1% with 0.3 micrograms/kg/min. These results suggest that ONHBF is autoregulated despite the change of perfusion pressure by NA administration. This response is different from that of CBF.
Kitanishi
K
K
Department of Ophthalmology, Izumiotsu Municipal Hospital, Osaka-fu, Japan.
Harino
S
S
Okamoto
N
N
Tani
Y
Y
Nishimura
K
K
D000818:Animals; D002415:Cats; D002829:Choroid / Q000098:blood supply* / Q000187:drug effects*; D007275:Injections, Intravenous; D017078:Laser-Doppler Flowmetry; D008297:Male; D009638:Norepinephrine / Q000008:administration & dosage*; D009900:Optic Nerve / Q000098:blood supply* / Q000187:drug effects*
D009638:Norepinephrine