Terry Spennetta

Decreases in serum high-density-lipoprotein cholesterol and total cholesterol resulting from naturally produced and recombinant DNA-derived leukocyte interferons☆

A three-phase study was conducted to examine the effect of leukocyte interferon administration on serum high-density-lipoprotein (HDL) cholesterol and total cholesterol levels. In the initial phase, human leukocyte interferon decreased HDL cholesterol (P less than 0.05) and total cholesterol (P less than 0.05) levels in patients with breast carcinoma. Decreases began with initiation of the interferon administration, were sustained throughout the period of treatment, and increased toward pretreatment values with discontinuation of interferon. In the second phase of the study, in neither of two comparison groups of women receiving cytotoxic chemotherapy, excluding interferon, did any similar decrease in HDL cholesterol occur. In a third comparison group of women being treated for metastatic breast carcinoma, a predicted and significant (P less than 0.01) drop in HDL cholesterol level without a concomitant lowering of total cholesterol level occurred immediately following the initiation of androgen therapy. To confirm that the observed cholesterol level decreases were associated with interferon rather than a contaminant thereof, analyses were also carried out on samples from a study utilizing interferon rather than a contaminant thereof, analyses were also carried out on samples from a study utilizing interferon produced by recombinant DNA techniques and purified to homogeneity. A similar decrease in HDL cholesterol (P less than 0.05) and total cholesterol (P less than 0.01) was observed. A definite relationship therefore appears to exist between the administration of human leukocyte interferon and decreased plasma levels of HDL cholesterol and total cholesterol.

Total cholesterol and HDL-cholesterol changes during acute, moderate-intensity exercise in men and women.

Chronic endurance exercise training has been associated with decreased levels of total cholesterol and increased HDL-cholesterol. To our knowledge rapid changes in cholesterol and HDL-cholesterol during acute exercise have not been described under controlled conditions. We studied 28 subjects (14 males and 14 females) during bicycle exercise for 40 min at a work intensity of 55% of their maximal oxygen consumption. Total and HDL-cholesterol levels were measured (and LDL-cholesterol calculated) at rest, 10, 20, 30, and 40 min of exercise, and 15 min postexercise. There was a significant (p less than 0.001) increase in HDL-cholesterol levels at 10 min of exercise (58.8 +/- 13.9 mg/dl, mean +/- SD) above rest (53.1 +/- 13.4 mg/dl) for all subjects. This increase persisted (p less than 0.001) at all time points throughout the exercise session, but declined by 15 min postexercise. There was a small, insignificant decline in LDL-cholesterol. It is concluded that apparent favorable changes in lipoprotein patterns occur acutely, and are sustained during short-term, moderate intensity exercise. Analyses of these changes appears necessary if the biochemical mechanisms which underlie these metabolic alterations are to be elucidated.

Determination of individual long-chain fatty acyl-CoA esters in heart and skeletal muscle

A method has been developed for determination of individual long-chain fatty acyl-CoA esters from heart and skeletal muscle using high performance liquid chromatography (HPLC). The esters were extracted from freezeclamped tissue of pig and rat hearts and rat skeletal muscle for analysis on a radially compressed C18 5μ reversephase column. Nine peaks in the extract with carbon chain lengths from C12 to C20 that subsequently disappeared on alkaline hydrolysis were identified. The major acyl-CoA peaks were 14∶1, 18∶2, 16∶0 and 18∶1 and additionally in rat heart 18∶0. Total long-chain acyl-CoA esters obtained by summation of the individual molecular species was 11.34±1.48 nmol/g wet wt. pig heart; 14.51±2.11 nmol/g wet wt. in rat heart, and 4.35±0.71 nmol/g wet wt. in rat skeletal muscle. These values were approximately 132% of those obtained using a separate procedure that measured total CoA by HPLC after alkaline hydrolysis of the esters. The described method demonstrates the quantitation of individual acyl-CoA species in muscle tissue. Therefore, it has a number of advantages in that it permits information to be obtained on the individual molecular species under various nutritional and metabolic conditions.

Separation and quantitation of long-chain free fatty acids in human serum by high-performance liquid chromatography.

A rapid, simple and highly sensitive reversed-phase high-performance liquid chromatographic method is described for the separation and quantitation of fatty acids in human serum using a very reactive fluorescent labeling reagent, 9-anthryldiazomethane. Quantitative esterification proceeds at room temperature without heat or catalysis. Baseline separation of nineteen select fatty acids from a standard mixture was achieved on two C18-bonded silica columns connected in tandem using stepwise gradient elution of an acetonitrile-methanol-water mobile phase. The eluent was monitored by a fluorescence detector (maximum excitation wavelength, 365 nm; maximum emission wavelength, 412 nm). The procedure was applied to the analysis of both saturated and unsaturated long-chain free fatty acids (C8 to C22) extracted from human serum. Sera from fasting and non-fasting subjects were analyzed to show the applicability of this assay to biological samples. Detection limit and recovery of free fatty acids in serum were less than 10 pmol/microliter and greater than 92%, respectively.

Effect of dietary fat on individual long-chain fatty acyl-CoA esters in rat liver and skeletal muscle.

The effect of dietary fat on the long-chain acyl-CoA ester profile of liver and skeletal muscle was investigated by feeding weanling rats 12%-fat diets composed of high-linoleic safflower oil (73% 18∶2n−6), high-oleic safflower oil (70% 18∶1n−9) or olive oil (70% 18∶1n−9) for six and ten weeks. Approximately 50% of both hepatic and skeletal muscle acyl-CoA esters comprised linoleoyl-CoA or oleoyl-CoA with high-linoleic or oleic feeding, respectively. Total hepatic acyl-CoA ester concentration was 40% higher (p<0.05) in rats fed 12% fat compared with controls fed a 4%-fat diet. These data demonstrate that the long-chain acyl-CoA ester profile of liver and skeletal muscle reflects the dietary fatty acid profile.