[The vascular effects of thrombin on canine and human arteries; their independence from the metabolism of arachidonic acid].

Independently of it's effects on the coagulation cascade, thrombin can interact with the endothelium and release vasodilatory mediators as prostacyclin, endothelium dependent relaxing factor and potentiate the vascular changes induced by vasoconstrictors like endothelin or cathecolamines. Therefore, in the present study we tested the effect of thrombin in the pulmonary and femoral canine arteries and compared it with the effects on human umbilical artery; we also explore the possible mechanism of action of thrombin-induced changes in vascular tone by using specific inhibitors. Thrombin induced a concentration-dependent and endothelium-dependent relaxation on canine arteries (pulmonary or femoral) and endothelium-independent contraction of human umbilical arteries, neither the relaxation nor the contraction were significantly affected by incubation of the vessels with: a cyclooxygenase inhibitor (indomethacin), lypooxygenase inhibitor (BW 755C) or a soup of antagonists (atropine, metysergyde, propanolol, meperamine or phenoribenzamine) to block muscarinic, histaminic, serotoninergic or adrenergic receptors.

Effects of avocado as a source of monounsaturated fatty acids on plasma lipid levels.

To examine the effects of avocado on plasma lipid concentrations, a three-diet trial involving 16 healthy volunteers was carried out. A diet rich in monounsaturated fatty acids using avocado as their major source (30% of the total energy was consumed as fat: 75% of the total fat from the avocado), with restriction of saturated fats and less than 300 mg of cholesterol per day was evaluated. Subjects also were in a free-diet period with the addition of the same amount of avocado.