Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:4.1.99.3 (PRE)
 1,923 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Few data are available regarding the effects of exercise training upon cardiac structure and performance in man. We evaluated the echograms of 24 normals before (PRE) and after (POST) 11 weeks of endurance exercise training. Conditioning consisted of a walk-jog-run protocol at 70% maximal heart rate for one hour four days per week. Training reduced heart rate and increased maximal duration and estimated oxygen consumption of treadmill exercise. Compared to PRE, the echogram in the POST training period revealed an increased left ventricular (LV) end-diastolic dimension (EdD), a decreased end-systolic dimension (EsD) and thus an increased stroke volume (EdD3-EsD3) and shortening fraction (EdD-EsD)/EdD). Cardiac output (CO) and peripheral vascular resistance (BP/CO X 80) were identical PRE and POST conditioning. Importantly, an increase in mean fiber shortening velocity was observed POST training as were increases in LV wall thickness, ECG voltage of S in V1 + R in V5, and LV mass. Thus endurance training was accompanied by increases in both LV dimension and mass as well as LV shortening fraction and contraction velocity as observed by echocardiogram.
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PMID:Alterations in ventricular mass and performance induced by exercise training in man evaluated by echocardiography. 61 10

This study sought to determine whether the ability to improve cardiorespiratory endurance and body composition is affected by the menopausal status of females. Twenty premenopausal females and 18 postmenopausal females, ages 35-49 and 47-66 yr, respectively, were randomly assigned to exercise and control groups depending on menopausal status. Both exercise groups (PRE-EX, N = 16; POST-EN, N = 14) participated in a progressive walking program (4 days/week for 9 weeks) at an intensity of 80% the age-adjusted heart rate maximum (80% HRM). Following training, both exercise groups significantly improved submaximal exercise capacity (SEC) as measured by oxygen consumption (l/min; ml/kg . min) and treadmill walking time at 80% HRM. The PRE-EX group significantly improved percent body fat and lean body weight, while there was no significant change in total body weight. The POST-EX group significantly improved total body weight and percent body fat with no significant change in lean body weight. Although some of these changes in body composition were statistically significant, overall the alterations were minimal. ANCOVA revealed exercise, not menopause, to be the effective treatment for improving percent body fat and SEC80%HRM. There were no significant differences between the PRE-EX and POST-EX groups in their ability to improve SEC80%HRM or to reduce percent body fat. The POST-EX group had a significantly greater reduction in total body weight, while the PRE-EX group had significantly greater increases in lean body weight. These findings suggest that the ability to favorably alter body composition and cardiorespiratory endurance through the aerobic conditioning of females is independent of menopausal status.
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PMID:Responses of pre- and post-menopausal females to aerobic conditioning. 398 68

The expression of a gene for photolyase in RBCF-1 cells, a line of cultured goldfish cells, is known to be enhanced by fluorescent light. We have now found that H2O2 is another strong inducer of cyclobutane pyrimidine dimer photolyase. Northern blot analysis suggested that regulation by H2O2 occurs at the transcriptional level and the time course of induction of photolyase by H2O2 was similar to that by fluorescent light. Treatment with fluorescent light in the presence of riboflavin, which is known as an endogenous photosensitizer, also enhanced the induction of photolyase. These results suggest the involvement of oxygen stress in the induction of photolyase by fluorescent light. A cell clone with high-level expression of the goldfish gene for photolyase was obtained by transfection with plasmids that expressed the goldfish photolyase in OL32 cells derived from another fish, the medaka (Oryzias latipes). The induction of the medaka gene for photolyase was not affected by the high-level expression of the goldfish gene for this enzyme.
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PMID:Induction of cyclobutane pyrimidine dimer photolyase in cultured fish cells by fluorescent light and oxygen stress. 774 81

8-(Methylsulfonyl)FAD reacts with a single cysteine residue (Cys293) in the flavin domain of Escherichia coli DNA photolyase to form an 8-(cysteinyl)FAD derivative covalently bound to the protein. About 80% protection against covalent attachment with 8-(methylsulfonyl)FAD was observed in the presence of an equimolar amount of FAD. Flavinylated photolyase retains the ability to repair pyrimidine dimers (15% of native activity) and to bind its antenna chromophore, 5,10-methenyltetrahydrofolate. Comparison of the properties of flavinylated enzyme with photolyase containing noncovalently bound 8-(methylthio)-FAD indicate that a perturbation is necessary to accommodate covalent bond formation. 8-(Methylthio)-FAD-reconstituted enzyme exhibits 95% of native activity. The aerobic stability of fully reduced and radical forms of 8-(methylthio)FAD enzyme is similar to that of native enzyme, whereas a radical form is not detected with flavinylated enzyme and the fully reduced enzyme is more easily oxidized by oxygen. The flavin in 8-(methylthio)FAD enzyme or flavinylated photolyase is shielded from solvent. However, the flavin environment in flavinylated enzyme is less hydrophobic as judged by spectral comparison with model 8-(alkylthio)flavins in various solvents. Enzyme containing noncovalently bound 8-(methylsulfonyl)-FAD was prepared by reconstitution with the fully reduced flavin which does not undergo covalent attachment. Covalent attachment was observed after reoxidation but probably involved dissociation and rebinding of oxidized 8-(methylsulfonyl)FAD. The results show that 8-(cysteinyl)FAD in flavinylated photolyase is at or near the normal flavin binding site.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Affinity probing of flavin binding sites. 2. Identification of a reactive cysteine in the flavin domain of Escherichia coli DNA photolyase. 791 92

It was the purpose of this investigation to examine the influence of a worksite aerobic training program on serum lipid and lipoproteins and cardiovascular fitness in female employees. Thirty-seven healthy but previously untrained, female employees (Ss) from Westinghouse Corporation, (College Station, Texas) volunteered for the study. Ss were randomly assigned to either an exercise group (Ex) (n = 20) or control group (C) (n = 17). Prior to training (PRE) and following training (POST), all Ss were measured for weight (WT), body composition (%FAT) and tested for maximal oxygen consumption (VO2 max). PRE and POST Lipid analysis included: total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), and triglycerides (TG). Following PRE testing, the Ex group aerobically trained by walking, jogging and/or cycling, at least 3 days per wk for 24 wks. Exercise training resulted in an improvement in VO2 max (p < 0.0006) and a 2 kg WT loss in Ex (p < 0.025) with no change in C. Both Ex and C Ss exhibited a loss in %-FAT (p < 0.0001), and a decrease in TC (p < 0.0001) and LDL-C (p < 0.0001). No differences were observed between groups or over the training period for VLDL-C or TG. Although HDL-C increased 6 mg/dl in the Ex group but not in C, this difference did not reach statistical significance (p < 0.0625). These results demonstrate that aerobic training by females in a worksite fitness program significantly improves cardiovascular fitness without altering lipids or lipoproteins.
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PMID:Lipid and lipoprotein changes in women following 6 months of exercise training in a worksite fitness program. 869 39

Leptin, the product of the ob gene, has been reported to be related to body fat in humans (Considine et al. N. Engl. J. Med. 334: 292, 1996). However, little is known about the physiology of this putative satiety signal in humans. The purpose of the present study was to determine whether leptin is related to body fat content in relatively lean endurance-trained adults. In addition, the effect of acute exercise on circulating leptin concentration was studied. Thirteen male runners, whose mean age, height, weight, %fat, and maximal oxygen consumption (VO2max) were 32.2 +/- 2.5 yr, 176.2 +/- 1.6 cm, 71.9 +/- 6.9 kg, 9.7 +/- 0.9%, and 62.9 +/- 2.2 ml.kg-1.min-1, respectively, were studied. Blood samples were obtained after an overnight fast and again immediately after the completion of a 20-mile run at 70% VO2max under controlled environmental conditions. Serum leptin was closely related to fat mass (r = 0.92) in the runners. Acute exercise had no detectable effect on serum leptin levels (PRE = 2.19 +/- 0.32 ng/ml, POST = 2.14 +/- 0.36 ng/ml). These data indicate that, even at a biological extreme of body fat, circulating leptin concentration is closely related to fat content. Furthermore, the data suggest that, in trained individuals with low leptin concentrations, acute exhaustive exercise has no immediate effect on circulating leptin concentration.
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PMID:Leptin is related to body fat content in male distance runners. 894 84

The cyclobutane pyrimidine dimer (CPD) photolyase in fish cells is known to be regulated by environmental factors, such as light, hydrogen peroxide and growth inhibition. The induction of CPD photolyase by light in cultured goldfish cells was dependent on the wavelength of the light, and UVA and blue light had high inductive activity. The spectrum for CPD photolyase activity was different from that for the induction. Treatment with blue or yellow light for a short time, which did not induce any CPD photolyase, induced high CPD photolyase activity in the presence of the photosensitizers, TPPS (monosulfonated meso-tetraphenyl porphine) and ALPS (aluminum phthalocyanine tetrasulfonate), respectively. These results suggest that the induction of CPD photolyase might be triggered by active oxygen produced by light and cellular photosensitizers. We also found that immediately after treatment with UVA, blue light or a photosensitizer in combination with light, cellular attachment to the substratum was enhanced, as was the CPD photolyase activity. Pretreatment with a flavonoid, quercetin, inhibited both photoinduction of CPD photolyase and enhancement of cellular attachment. Vitamin E inhibited only photoinduction of CPD photolyase activity. Treatment with H7, a strong inhibitor for protein kinase C, after light treatment inhibited photoinduction of CPD photolyase activity, but an analogue of H7, Ha1004, which is a weak inhibitor of protein kinase C, did not have such an effect.
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PMID:Induction of cyclobutane pyrimidine dimer photolyase in cultured fish cells by UVA and blue light. 897 35

The purpose of this study was to evaluate the effects of football training on maximal oxygen uptake (VO2max), ventilatory threshold (VT) and kinetics of ventilation and gas exchange variables to sinusoidal work load. The sinusoidal work load during cycling exercise was varied from 30 watts to 60% of VO2max (60% VO2max) with a period of 2 min. O2 uptake (VO2), CO2 output (VCO2), minute ventilation (VE) and heart rate (HR) were measured on a breath-by-breath basis using a computer system. Training periods were continued for 9 months. Six males who had no football experience were performed in which VO2max, VT, and the kinetics of each variable were measured for 3-month intervals (PRE, TR.3, TR.6, and TR.9). They usually underwent football training, such as sprint and strength training for 2-3 hours day-1, 6 days week-1. Mean VO2max was significantly increased at TR.3 and TR.6. VT was also significantly increased during the training period. The amplitude of VO2, VCO2, VE, and HR responses during sinusoidal exercise unchanged during the training period. Phase shifts to work load in VO2 and HR responses did not significantly change during the 9 months, but the phase shift in VCO2 and VE responses significantly continued increasing as the training intervals progressed. These results suggest that football training does not significantly affect the development of the kinetics of VO2 and HR during submaximal exercise, but that it dramatically increases VO2max and VT values.
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PMID:Effects of football training on ventilatory and gas exchange kinetics to sinusoidal work load. 940 45

The purpose of this study was to evaluate the serum level of serotonin (5-HT) during rest and response to exercise in subjects with spinal cord injury (SCI) with different levels of physical activity. Twenty-five male subjects with traumatic paraplegia, the neurological levels being between T1 and T12, volunteered for the study. They were divided into two groups matched for age, weight and time since injury, according to the level of physical activity: 14 inactive and 11 subjects regularly involved in sports activity and considered active. They all performed a maximal spiroergometric test with an arm crank ergometer. Two samples of blood were collected for 5-HT determination, during rest (PRE) and immediately after exercise test (POST). Serum 5-HT concentration was measured by high performance liquid chromatography using electrochemical detection (HPLC-ED). The results showed that peak oxygen uptake (VO2peak) was higher in the active group (27.08 +/- 2.60 vs 18.89 +/- 5.58 mL.kg-1.min-1, P < 0.001). There were no significant differences between the inactive and active groups for the 5-HT PRE (respectively 176.96 and 193.73 ng.mL - 1, P > 0.05) or POST values (275.44 vs 311.05 ng.mL-1, P > 0.05). Both groups showed an increment in 5-HT after maximal exercise, but only in the active group it reached statistical significance (Wilcoxon test, P < 0.02). Our results show that chronic paraplegic individuals have normal resting serum serotonin levels and normal response to exercise. The relationship between training status, mood elevation and 5-HT in SCI could not be established in the present study, and further investigation is needed to clarify this issue.
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PMID:Serum level of serotonin during rest and during exercise in paraplegic patients. 947 Nov 32

Peak oxygen consumption (peak VO2) has become a critical component in the evaluation of heart transplant recipients (HTR). In these patients, peak VO2 remains low after cardiac transplantation mainly because of persisting peripheral limitations in the working muscles. Muscular electrical stimulation, on the other hand, has been shown to enhance the oxidative capacity of healthy muscle. It was the purpose of our investigation to study the effects of ES on the peak VO2 of HTR. Fourteen (11 males and 3 females) HTR (age: 57+/-7yr, mean +/- SD; height: 163+/-7 cm, weight: 70.5+/-8.6 kg) were selected as subjects and each of them was randomly assigned to one of two groups: (a) group EXP (n = 7), receiving electrical stimulation on both quadriceps muscles during a period of 8 weeks, and (b) group CONT (n = 7), not receiving electrical stimulation. Before (PRE) and after (POST) the aforementioned 8-week period, respectively, all the subjects performed a cardiopulmonary exercise test (ramp protocol) on a cycle ergometer for peak VO2 determination. PRE values of peak VO2 were similar in both groups (17.1+/-2.0 vs 16.9+/-3.8ml x kg(-1) x min(-1) in EXP and CONT, respectively). However, peak values of VO2 significantly increased in EXP (p < 0.05) after the period of electrical stimulation (POST peak VO2: 18.7+/-2.0ml x kg(-1)), whereas no change was observed in CONT (POST peak VO2: 16.2+/-3.2 ml x kg(-1) x min(-1)). In conclusion, electrical stimulation could therefore be used to improve the functional capacity of HTR, and might be included in the rehabilitation programs of this population group.
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PMID:Effects of muscle electrical stimulation on peak VO2 in cardiac transplant patients. 972 Oct 54


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