To determine the effect of adenosine on the venous system, mean circulatory filling pressure (MCFP) was determined during infusion of intravenous (i.v.) adenosine (66.5 to a maximum of 532 μg · kg-1 · min- 1) in 9 awake instrumented rats before and during ganglionic blockade with i.v. hexamethonium, 0.6 mg · kg-1 · min-1. MCFP, the equilibrated pressure (mm Hg) occurring when the circulation is arrested by transient inflation of a balloon in the right atrium, is inversely related to total venous capacitance. Both adenosine and hexamethonium caused a reduction in mean arterial pressure (MAP); heart rate (HR) decreased during adenosine infusion in the blocked, but not the unblocked, state. In the unblocked state, baseline MCFP was 6.5 ± 0.3 mm Hg; hexamethonium caused baseline MCFP to decrease to 5.3 ± 0.3 mm Hg. In both the unblocked and the blocked state, adenosine caused a dose-related decrease in MCFP [6.5 ± 0.3 to 5.5 ± 0.6 mm Hg (532 μg · kg-1 · min-1 adenosine dose) unblocked state; and 5.3 ± 0.3 to 4.3 ± 0.3 mm Hg (400 μg · kg-1 · min-1 adenosine dose) blocked state]. This decrease in MCFP induced by adenosine was highly significant. Intravenous adenosine, in an awake instrumented rat model, increases venous capacitance, with and without ganglionic blockade.
|Original language||English (US)|
|Number of pages||5|
|Journal||Journal of Cardiovascular Pharmacology|
|State||Published - Jan 1 1992|
All Science Journal Classification (ASJC) codes
- Cardiology and Cardiovascular Medicine