Effects of alpha-tocopherol on superoxide production and plasma intercellular adhesion molecule-1 and antibodies to oxidized LDL in chronic smokers.

Antioxidants have been postulated to exert beneficial effects in atherosclerosis. Atherosclerosis is associated with raised plasma levels of soluble intercellular adhesion molecule-1 (sICAM-1) and autoantibodies against oxidized low-density lipoprotein (oxLDL). It is not known whether antioxidants affect these plasma factors in chronic smokers.

Beta-VLDL accumulation in familial dysbetalipoproteinemia is associated with increased exchange or diffusion of chylomicron lipids to apo B-100 containing triglyceride-rich lipoproteins.

To gain more insight into the accumulation of beta-very low density lipoprotein (beta-VLDL) in familial dysbetalipoproteinemia (FD), we followed the courses of the levels of retinyl palmitate (rp), alpha-tocopherol (alpha-T) and apolipoprotein (apo) B-48 in various lipoprotein fractions for up to 48 h in eight patients with FD and six normolipidemic control subjects after an oral fat load (50 g fat/m2 containing 150000 IU of rp and 5000 IU of alpha-T). Alpha-T was added because of its rapid transfer to other lipoproteins. Fasting apo B-48 concentration in FD was normal to strongly elevated, dependent on the fasting lipid concentrations.

A study of the chylomicron metabolism in WHHL rabbits after fat loading. Discrepancy between results based on measurement of apoprotein B-48 or retinyl palmitate.

We studied the metabolism of chylomicrons in homozygous Watanabe heritable hyperlipidaemic (WHHL) rabbits and in cholesterol-fed or normally fed New Zealand White (NZW) rabbits by measuring the concentrations of apoprotein B-48 and of retinyl palmitate in their serum after feeding fat plus this vitamin according to two different protocols. Compared with NZW controls, retinyl palmitate accumulated in both hyperlipidaemic groups under study, not only in the d less than 1.019 fraction but also in the low-density lipoprotein (LDL) fraction.

Effects of isometric exercise on blood cell adrenoceptors in essential hypertension.

The effect of handgrip (HG) isometric exercise on plasma catecholamines, alpha 2-adrenoceptors on platelets and beta 2-adrenoceptors on lymphocytes was studied in normotensive subjects (NT) and essential hypertensive subjects (HT). Whereas systolic blood pressure (SBP) increases were similar in NT and HT subjects, diastolic blood pressure (DBP) and heart rate (HR) increased more in the former group. Baseline values and changes in plasma epinephrine (E) and norepinephrine (NE) did not differ between both groups.

Adrenoceptors on blood cells in patients with essential hypertension before and after mental stress.

The effect of mental arithmetic (MA) on alpha 2- and beta 2-adrenoceptors on platelets and lymphocytes, respectively, and on plasma catecholamines was studied in normotensive (NT) and essential hypertensive (HT) subjects. There were no significant differences in responses of blood pressure, forearm blood flow (FBF) and heart rate to MA between the two groups. Baseline values and changes in adrenaline and noradrenaline levels during MA were similar in NT and HT.