The reversibility of canine vein-graft arterialization.

We assessed the reversibility of functional and morphological changes of arterialized vein segments by returning them to the venous circulation. Thirteen dogs underwent right carotid and femoral veno-arterial grafting. After 12 weeks, veno-arterial grafts were removed for contractility (norepinephrine [NE] and 5-hydroxytryptamine [5-HT]), luminal prostacyclin (PGI2), and morphometric analyses; the remaining segments were used as left jugular and femoral veno-venous grafts.

Mechanisms responsible for inhibition of vein-graft arteriosclerosis by fish oil.

Favorable changes in lipoproteins, inhibition of platelet aggregation, reduction of serum thromboxane (TX), altered plasma-membrane fluidity, and reduced production of growth factors (mitogens) have all been implicated as possibly being involved in the inhibition of arteriosclerosis by fish oil (FO), which is rich in omega 3 fatty acids; however, causal relations are mostly lacking. Several putative mechanisms responsible for the salutary effects of FO were investigated in a canine model of accelerated vein-graft arteriosclerosis. Venoarterial autografts (N = 192) were implanted in 48 hypercholesterolemic dogs divided into six groups: group A, control; B, FO (as MaxEPA, 200 mg/kg/day eicosapentaenoic acid); C, aspirin (ASA, 50 mg/kg/day); D, TX synthetase inhibitor (TXSI [CGS-12970], 10 mg/kg/day); E, FO + ASA; and F, FO + TXSI.