Adenosine modulates vascular resistance and fluid filtration in isolated rat lungs.
In adult respiratory distress syndrome, a major concern is to reduce increments in pulmonary vascular resistance (PVR) and maintain the patency of lung microvessels. We have investigated the effects of adenosine, a potent systemic vasodilator, on PVR and fluid filtration rate (FFR) in isolated blood-perfused rat lungs. The preparations were undamaged or subjected to fat emulsion-induced injury simulating ARDS. In undamaged lungs adenosine caused a significant dose-dependent reduction of hypoxia-induced increases in PVR. Furthermore, the increase in FFR upon elevation of left atrial pressure by 0.77 kPa was significantly hampered by adenosine, 24 nmol.ml-1.min-1. Employing the same rate of infusion, adenosine, in a group of injured preparations, significantly reduced the rise in PVR towards baseline and completely abolished the further increase upon a superimposed injection of serotonin. In another series of preparations with lung injury randomly assigned to an adenosine group and a control group, adenosine significantly reduced FFR. Thus, adenosine, even when infused at low rates, reduced increments in PVR and fluid filtration, both in undamaged and in fat emulsion-injured isolated lungs.
Jolin
A
A
Department of Anesthesiology, University of Tromsö, Norway.
Helset
E
E
Tollåli
T
T
Bjertnaes
L J
LJ
D000241:Adenosine / Q000494:pharmacology*; D000818:Animals; D015633:Extravascular Lung Water / Q000187:drug effects* / Q000502:physiology; D066298:In Vitro Techniques; D008168:Lung / Q000187:drug effects* / Q000502:physiology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D014655:Vascular Resistance / Q000187:drug effects* / Q000502:physiology
D000241:Adenosine