Effects of low- and high-repetition resistive training on lipoprotein-lipid profiles.

Thirty-seven healthy untrained males (age = 21 +/- 1 yr; range = 19 to 35 yr) were studied to determine the effects of 10 wk of low- and high-repetition resistive training on lipoprotein-lipid profiles. Subjects were assigned to 1 of 3 groups: a low-repetition group (N = 15) that trained using 4 to 6 repetitions maximum or a high-repetition group (N = 14) that used 14 to 16 repetitions maximum in their training or to an inactive control group (N = 8). The number of sets was adjusted to equalize workloads. Muscular strength increased significantly in both training groups as indicated by the increase in the one-repetition maximum test (P less than 0.05). VO2max, body weight, and percent body fat did not change in either of these groups. However, fat-free weight increased significantly in both training groups (both P less than 0.05). The low-repetition training program resulted in no significant changes in the plasma concentrations of triglycerides (104 +/- 15 vs 89 +/- 8), total cholesterol (150 +/- 7 vs 141 +/- 6), high-density lipoprotein (HDL)-cholesterol (40 +/- 1 vs 41 +/- 2), and HDL2-cholesterol (7 +/- 1 vs 7 +/- 1). A similar pattern was observed for the high-repetition group ([i.e., no significant changes in the concentrations of triglycerides (87 +/- 10 vs 89 +/- 8), total cholesterol (148 +/- 6 vs 162 +/- 6), HDL-cholesterol (40 +/-2 vs 40 +/- 2), and HDL2-cholesterol (6 +/- vs 1 vs 7 +/- 2)]. All lipid values were expressed in milligrams per deciliter (mean +/- SE).(ABSTRACT TRUNCATED AT 250 WORDS)

High-density-lipoprotein cholesterol in bodybuilders v powerlifters. Negative effects of androgen use.

To determine the relationship between lipid profiles and the type of weight training and to assess the effects of anabolic-androgenic steroids on lipids, bodybuilders and powerlifters of similar age, body fat, and testosterone levels were studied before and after androgen use. Before androgen administration powerlifters had lower levels of plasma high-density-lipoprotein cholesterol (HDL-C) and HDL2-C (38 +/- 2; 6 +/- 1 mg/dL; means +/- SE, n = 8) than bodybuilders (55 +/- 2; 12 +/- 1 mg/dL; n = 8) and runners of comparable age and body fat (47 +/- 2; 14 +/- 2 mg/dL; n = 8), while levels of low-density-lipoprotein cholesterol (LDL-C) were higher in powerlifters (138 +/- 10 mg/dL) than in bodybuilders (104 +/- 7 mg/dL) and runners (110 +/- 6 mg/dL). Therefore, powerlifters had higher LDL-C/HDL-C ratios (3.7 +/- 0.3) than bodybuilders (2.0 +/- 0.2) and runners (2.4 +/- 0.2). Androgen use by eight bodybuilders and four powerlifters lowered values of both HDL-C and HDL2-C by 55% and raised values of LDL-C (61% +/- 10%) and LDL-C/HDL-C ratios (280% +/- 40%). Therefore, the training regimen of bodybuilders is associated with a more favorable lipid profile than the training used by powerlifters. Androgen use by strength-trained athletes may increase their risk for coronary heart disease.

Evaluation of a portable ultrasonoscope in assessing the body composition of college-age women.

Subcutaneous fat tissue thickness was measured ultrasonically on 66 females between the ages of 18-26 yr by using a portable ultrasonoscope and by skinfold caliper. Measurements were obtained at seven sites: triceps, biceps, subscapula, suprailiac, abdomen, calf, and thigh. In addition, body density (Db) was measured by the underwater weighing technique. Mean Db was 1.0458 gm X cc-1, corresponding to a percent fat of 22.8% (range = 11.3-35.8%). Correlations between ultrasonic and skinfold measurements were significant (P less than 0.05) at all sites. The highest was noted at the suprailiac (r = 0.86) and the lowest was at the thigh (r = 0.75). Test-retest reliability for ultrasonic measurements, taken on separate days, ranged from r = 0.87 at the triceps to r = 0.99 at the biceps. Four significant regression equations for predicting Db were developed, two utilized skinfolds and two utilized ultrasonic measurements of tissue thickness. The equation with the greatest multiple correlation (R = 0.80) utilized the suprailiac, subscapula, and thigh skinfolds. The equation using ultrasonic measurements taken at the suprailiac and thigh sites demonstrated a multiple correlation of R = 0.78. This instrument is a reliable, portable, and non-invasive alternative to the skinfold caliper in obtaining field measurements of body composition.

Characterization of RNA transcripts and virally coded proteins synthesized in mouse fibroblasts transfected with hepatitis B DNA: HBeAg synthesis in HBcAg-negative cells with active core-antigen genes.

A line of mouse cells expressing hepatitis B virus (HBV) surface and 'e' antigens identical in their physico-chemical properties to antigens from patients infected with HBV was isolated after transfection of 3T3 cells with cloned HBV DNA. The studies reported here indicate that the cells contain uninterrupted copies of the entire HBV genome which are unmethylated on CCGG sites and have no gross deletions or rearrangements. The entire core region is transcribed into polyadenylated RNAs large enough to serve as messengers for production of viral core antigen (HBcAg) yet no HBcAg can be detected. This suggests that the cells produce a primary translation product copied from the HBcAg messenger which either cannot assume the proper configuration for display of HBcAg determinants or is rapidly converted to HBeAg by proteolysis.

Binding of a 4-methyl-4-aza-steroid to 5 alpha-reductase of rat liver and prostate microsomes.

A tritium labeled 5 alpha-reductase inhibitor, [1,2-3H] 17 beta-N,N-diethylcarbamoyl-4-methyl-4-aza-5 alpha-androstan-3-one ([3H]4-MA), binds reversibly to a high affinity site (Kd, 6.5 nM) in liver microsomes from male rats. The binding requires a nicotinamide nucleotide coenzyme; NADH is at least 100 times less potent than NADPH, and NADP+, NAD+, flavin adenine dinucleotide, coenzyme A, and ADP are inactive. The relative potencies of 13 steroids as inhibitors of the binding of [3H]4-MA to liver microsomes correlate with their relative potencies as inhibitors of the conversion of [14C]testosterone to [14C]5 alpha-dihydrotestosterone by liver microsomes. Comparison of liver microsomes from mature female rats and microsomes from mature male rat liver, ventral prostate, spleen, kidney, and skeletal muscle shows that their NADPH-dependent [3H]4-MA binding capacities correlate with their levels of 5 alpha-reductase activity. These results suggest that [3H]4-MA binds specifically to 5 alpha-reductase in a NADPH-dependent manner. 5 alpha-Reductase was solubilized from liver microsomes with a detergent, Lubrol-WX, and the solubilized enzyme also binds [3H]4-MA. The relative potencies of 13 steroids as inhibitors of rat ventral prostate and liver 5 alpha-reductase are the same, strongly suggesting that the 5 alpha-reductases in the two tissues are the same.

Effect of immersion on RV in young women: implications for measurement of body density.

The effect of immersion to the chin on the residual volume (RV), vital capacity (VC), functional residual capacity (FRC), and expiratory reserve volume (ERV) of 27 normal females, mean age 20.7 years, was studied. Mean determinations decreased (P less than .01) for all measured lung volumes from the corresponding measurement with the subjects in air (RV 17.4%, VC 12.1%, FRC 46.9%, ERV 70.3%). In addition, the effect of the decreased RV on body density (Db) and percent fat (% fat) determinations were also examined. The mean reduction in RV of 17.4% (195 ml) corresponded to a mean relative error of only 0.35% in the Db measure. It is recommended that when measuring RV to later determine Db by hydrostatic weighing, the determination be made with subject in air. This procedure will allow for greater ease in measurement for both the subject and researcher with no loss in physiologic accuracy.

Dihydromevinolin, a potent hypocholesterolemic metabolite produced by Aspergillus terreus.

A new, potent hypocholesterolemic agent is produced by cultures of Aspergillus terreus. The isolation of the compound and its characterization as 4a,5-dihydromevinolin containing a trans-fused octahydro-naphthalene system are described. Comparative data for dihydromevinolin and mevinolin in three biological assays are given: in vitro inhibition of HMG-CoA reductase, inhibition of sterol synthesis in cell cultures, and inhibition of cholesterol synthesis in vivo in rats.