Endothelium function is protected by albumin and flow-induced constriction is independent of endothelium and tone in isolated rabbit femoral artery.
To investigate the preservation of endothelial function, we perfused two segments of one rabbit femoral artery (n = 8) in a pressure myograph in parallel, both with Tyrode, but one with 0.6% albumin added. The change in the outer diameter of the vessels [preconstricted with norepinephrine (NE) to 70%] in response to acetylcholine as an indicator of the endothelial function, was repeatedly measured over 5 h after the equilibration. The difference between the acetylcholine responses of the two vessel segments was significant (p < 0.05) after a perfusion period of 4 h. We also investigated whether flow-induced constriction is dependent on (1) the presence of endothelium and (2) the level of preconstriction. We therefore perfused segments of rabbit femoral arteries (n = 5) with Tyrode with 0.6% albumin. If acetylcholine-induced dilatation was present, a flow-diameter relation was determined at two constriction levels: about 60% (high) and 90% (low) of the passive outer diameter. Both determinations were repeated after mechanical endothelium removal (checked functionally and histologically). A similar decrease in diameter (about 7%) with an increase in flow ranging from 0 to 1,330 microliters/min was found in all conditions. We conclude that the addition of (0.6%) albumin protects endothelial function in the rabbit femoral artery when perfused in the low-flow range for a period longer than 4 h. We also found that flow-dependent constriction is neither influenced by the presence of the endothelium nor by the level of tone induced with NE.
Hoogerwerf
N
N
Laboratory for Physiology, Free University, Amsterdam, The Netherlands.
Zijlstra
E J
EJ
van der Linden
P J
PJ
Westerhof
N
N
Sipkema
P
P
D000818:Animals; D002417:Cattle; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D005263:Femoral Artery / Q000187:drug effects / Q000502:physiology*; D007552:Isotonic Solutions / Q000494:pharmacology; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000502:physiology; D011817:Rabbits; D012039:Regional Blood Flow / Q000502:physiology*; D012709:Serum Albumin / Q000494:pharmacology*; D014661:Vasoconstriction / Q000502:physiology*
D007552:Isotonic Solutions; D012709:Serum Albumin; C037692:Tyrode's solution