title: Measurement of vasoactivity in the guinea-pig choroid.
abstract: OBJECTIVE
  A perfusion system for studying the vasoactive properties of the guinea-pig choroid is described.
  
  
  METHODS
  The principle of operation is that the vascular resistance of the entire vascular network of an isolated, perfused eye can be monitored by recording the pressure required to deliver a constant flow of perfusate through the network. Delivery of the pharmacological agent of interest into the perfusate stream and the subsequent determination of the magnitude of any induced pressure changes allows the vasoactive potency of various agonists to be assessed.
  
  
  RESULTS
  The baseline vascular resistance was 1.35 +/- 0.16 mmHg min/microL (mean +/- SEM; n = 10) and the mean response to intraluminal 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 properties of the guinea-pig choroid in greater detail.
authors.affiliation: Lions Eye Institute. Nedlands, Australia. cringle@cyilene.uwa.edu.au
authors.forename: S J
authors.initials: SJ
authors.lastname: Cringle
authors.forename: D Y
authors.initials: DY
authors.lastname: Yu
authors.forename: V A
authors.initials: VA
authors.lastname: Alder
authors.forename: E N
authors.initials: EN
authors.lastname: Su
authors.forename: P K
authors.initials: PK
authors.lastname: Yu
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D002829:Choroid / Q000098:blood supply* / Q000187:drug effects; D001330:Electronic Data Processing; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007552:Isotonic Solutions / Q000494:pharmacology; D010477:Perfusion / Q000379:methods; D012171:Retinal Vessels / Q000187:drug effects / Q000502:physiology; D014655:Vascular Resistance / Q000187:drug effects / Q000502:physiology
chemical_list: D007552:Isotonic Solutions; C051865:Krebs-Ringer solution