Purpose: A perfusion system for studying the vasoactive properties of
the guinea-pig choroid is described. Methods: The principle of operati
on is that the vascular resistance of the entire Vascular network oi a
n isolated, perfused eye can be monitored by recording the pressure re
quired to deliver a constant flow of perfusate through the network Del
ivery of the pharmacological agent of interest into the perfusate stre
am and the subsequent determination of the magnitude of any induced pr
essure changes allows the vasoactive potency oi various agonists to be
assessed. Results: The baseline vascular resistance was 1.35 +/- 0.16
mmHg.min/mu L (mean +/- SEM; n = 10) and the mean response to intralu
minal delivery of 124 mmol/L K+ Krebs was an increase in resistance of
297 +/- 67%. Vasoactive responses were sustainable for more than 8 h.
Conclusions: This system will now be used to study the vasoactive pro
perties of the guinea-pig choroid in greater detail.