Serum lipid and lipoprotein concentrations following exposure to ozone.

The effects of exposure to ozone (O3) on concentrations of serum lipids and lipoproteins were investigated. Male and female guinea pigs were exposed to O3 at 1 ppm for two weeks. Serum concentrations of cholesterol, triglycerides, low density (LDL) and very low density (VLDL) lipoproteins were elevated after O3 exposure, particularly in males. During O3 exposure the food intake per day decreased (for a constant body weight), suggesting that metabolic rate and possibly basal metabolic rate was lower. Lung wet weights increased during O3 exposure by 87% for males and 45% for females. When individual lung weight/body weight ratios were correlated with cholesterol and LDL values from the same animal, a high correlation is found for males (r = 0.81, P less than 0.05), suggesting that there may be a relationship between lipoprotein elevations and lung damage for males. Because elevated concentrations of lipids and lipoproteins in humans increase the risk of coronary heart disease (CHD), the lipoprotein results suggest that an epidemiological study of the incidence of CHD with metropolitan O3 levels may be warranted.

Serum lipoprotein concentrations in cystic fibrosis.

Two major classes of lipoproteins, low density and high density, are decreased in the serum of patients with cystic fibrosis; major apoproteins are also decreased. Since essential fatty acids and certain fat-soluble vitamins depend on lipoproteins for transport in the serum, knowledge of lipoprotein levels in cystic fibrosis patients could prove valuable in understanding (i) the basis for the abnormally low serum levels of these fatty acids and vitamins and (ii) the effects of therapies involving these molecules.

Electrophoretic analysis of brain proteins from young adult and aged mice.

The purpose of this study was to electrophoretically examine proteins from mice of different ages to determine whether general changes occurred in protein levels during senescence and to relate the data to specific ageing hypotheses involving proteins. Proteins from whole brain, brain regions, soluble and ribosomal brain fractions, from young adult and senescent mice, were totally solubilized and subjected to polyacrylamide slab gel electrophoresis. The resulting gel patterns were than compared by examining the intensity of gel bands of the same migration distance. Positive controls were used to establish the high sensitivity of the electrophoretic method. For example, band intensity differences were observed when brain proteins from different species, different periods of growth and development, normal and mutant mice, and different brain regions were compared. Virtually all band intensities and therefore, corresponding brain protein concentrations were unchanged when patterns from senescent mice were compared to patterns from younger adult mice. These results provide evidence against ageing hypotheses involving: (1) progressive programmed ageing; (2) protein cross-linking, and (3) a systematic shutdown of gene activity. The few, select, protein band changes that did occur provide evidence that (1) the volume of the brain vascular system decreases with age, and (2) the brain S-100 protein concentration increases with age.