Validation of a flow-differential technique for the recording of splenic blood-volume changes to vasoactive agents.
Splenic blood-volume changes to norepinephrine were determined in the anesthetized cat by recording the integral of the difference between splenic arterial flow and splenic venous flow (flow-differential technique) with ultrasonic transit-time flowmeters, and the changes recorded with this technique were compared with those recorded with an independent technique, the gravimetric method. Norepinephrine (0.003-0.3 microgram/min/kg of body weight) induced dose-related decreases in splenic volume, and the values recorded by the flow-differential technique were not significantly different from those recorded with the gravimetric technique. The values recorded by the two methods were highly correlated (r = 0.86). The slope of the line plotting the relation between the two methods was close to unity (0.97 +/- 0.12), and the intercept of the line was close to zero (-0.46 +/- 1.6 ml). The results suggest that the recording of the flow differential between splenic arterial flow and splenic venous flow with ultrasonic transit time flowmeters is a valid method for the recording of splenic blood-volume changes to vasoactive agents.
Xavier
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F
Department of Pharmacology, Faculty of Medicine, University of Saskatchewan, Saskatoon, Canada.
Yu
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McNeill
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JR
D000818:Animals; D001783:Blood Flow Velocity / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D001810:Blood Volume / Q000187:drug effects*; D002415:Cats; D004305:Dose-Response Relationship, Drug; D005260:Female; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology*; D012039:Regional Blood Flow / Q000187:drug effects; D012212:Rheology / Q000379:methods; D013154:Spleen / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000187:drug effects*; D018608:Ultrasonography, Doppler; D014662:Vasoconstrictor Agents / Q000494:pharmacology*
D014662:Vasoconstrictor Agents; D009638:Norepinephrine