Bogner B, Tockner B, Runge C, Strohmaier C, Trost A, Branka M, Radner W, Kiel JW, Schroedl F, Reitsamer HA. The effect of vasopressin on choroidal blood flow, intraocular pressure, and orbital venous pressure in rabbits.
Invest Ophthalmol Vis Sci 2011;
52:7134-40. [PMID:
21791588 PMCID:
PMC3207716 DOI:
10.1167/iovs.11-7791]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Revised: 07/06/2011] [Accepted: 07/15/2011] [Indexed: 12/24/2022] Open
Abstract
PURPOSE
To investigate the effects of arginine-vasopressin (AVP) on intraocular pressure (IOP), orbital venous pressure (OVP), and choroidal blood flow (ChorBF) regulation in anesthetized rabbits.
METHODS
Mean arterial pressure (MAP), IOP, and OVP were measured by direct cannulation of the central ear artery, the vitreous, and the orbital venous sinus, respectively. Laser Doppler flowmetry was used to record ChorBF. To change the perfusion pressure (PP), MAP was manipulated mechanically with occluders around the aorta and vena cava. In the first group of animals (n = 11) the dose-response relationship was measured. In the second group of animals (n = 8) pressure-flow relationships were determined at baseline and in response to intravenous application of a low (0.08 ng/kg/min) and a high (1.33 ng/kg/min) infusion rate of AVP.
RESULTS
AVP caused a dose-dependent increase of MAP and choroidal vascular resistance (ChorR), whereas IOP, OVP, ChorBF, and heart rate (HR) were decreased. In contrast to the high infusion rate, the low infusion rate of AVP had no effect on baseline ChorBF. However, the pressure-flow relationship was shifted downward significantly by both infusion rates at PP below baseline.
CONCLUSIONS
AVP reduces IOP and OVP significantly and is a potent vasoconstrictor in the choroidal vascular bed. In the choroid, the effect of AVP is not only dose-dependent, but also PP-dependent, which is indicated by the reduced perfusion relative to control with low-dosed AVP at low PP.
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