High-dose testosterone supplementation disturbs liver pro-oxidant/antioxidant balance and function in adolescent male Wistar rats undergoing moderate-intensity endurance training

In some countries, anabolic-androgenic steroid abuse is rampant among adolescent boys and young men, including some of those seeking physical fitness and/or pleasing appearance through various exercise types. This tactic carries the risk of severe harmful health effects, including liver injury. Most anabolic-androgenic steroid stacking protocols employed are based on the use of the ‘prototypic’ anabolic-androgenic steroid testosterone and/or its esters. There is a vast body of data on the effects of anabolic-androgenic steroids’ abuse combined with physical exercise training on the liver antioxidant barrier in adult subjects, whereas those concerning adolescents are scant. This study aimed to assess, in adolescent male Wistar rats undergoing a 6-week moderate-intensity endurance training (treadmill running), the influence of concurrent weekly supplementation with intramuscular testosterone enanthate (TE, 8 or 80 mg/kg body weight/week) on selected indices of liver status and oxidative stress. The rats were sacrificed, and their livers and blood samples were harvested two days after the last training session. High-dose TE treatment significantly reduced body and liver weight gains. Neither low-dose nor high-dose TE treatment affected liver α-tocopherol or γ-tocopherol content, whereas low-dose TE treatment significantly lowered hepatic reduced glutathione content. TE treatment significantly elevated liver thiobarbituric acid-reactive substances content and blood activities of alkaline phosphatase and γ-glutamyltransferase, but not of aspartate aminotransferase or alanine aminotransferase. Liver catalase activity was lowered by >50% in both TE-treated groups, while superoxide dismutase activity was significantly but slightly affected (−15%) only by the high-dose TE treatment. Glutathione peroxidase and glutathione reductase activities were not significantly altered. TE treatment significantly increased liver thiobarbituric acid-reactive substances content and lowered blood HDL-cholesterol, but did not significantly affect LDL-cholesterol or triglycerides level. In conclusion, high-dose TE treatment significantly disturbed liver antioxidant barrier and prooxidative-antioxidative balance and hence counteracted favorable effects of concurrent moderate-intensity endurance training in adolescent male rats.

Chest pain in an elite master ultra-marathon runner: a case report with a follow-up on his subsequent athletic activity

Ultra-marathon running has enjoyed increasing popularity, with the number of master ultra-marathon runners growing annually. This study presents a case of a 51-year-old highly experienced long-distance runner (body mass: 65.1 kg, body height: 168 cm), who took part in a 48-h ultra-marathon race held in 2010, but dropped out of the competition due to acute cardiac problems manifested after 16 h of running and having completed a distance of 129 km. Two weeks following the race, intense cardiac examination was performed to explain the drop-out due to chest pain. A 12‑lead electrocardiogram, a 2D transthoracic echocardiography in 3 apical projections of the left ventricle, a computed tomography of the chest, an invasive coronary angiography and a maximal oxygen uptake (VO_2max) test were performed. The 12-lead ECG revealed a negative T wave in III and aVF without morphological abnormalities. The echocardiographic examinations presented a normal size and function of the heart chambers, and a normal valvar structure and function (only trivial mitral and tricuspid regurgitation was observed). The invasive coronary arteriography - due to an increased calcium score in the CT scan - showed only a non-significant systolic dynamic narrowing in the eighth segment of the left anterior descending artery due to a muscle bridge. The physical performance characteristics of the athlete and a follow-up history of his athletic activity showed that the cardiac problems he had experienced during the ultra-marathon race did not prevent him from being active in sport. Int J Occup Med Environ Health. 2020;33(4):523-34.

Effects of Six-Week Ginkgo biloba Supplementation on Aerobic Performance, Blood Pro/Antioxidant Balance, and Serum Brain-Derived Neurotrophic Factor in Physically Active Men

Extracts of Ginkgo biloba leaves, a natural source of flavonoids and polyphenolic compounds, are commonly used as therapeutic agents for the improvement of both cognitive and physiological performance. The present study was aimed to test the effects of a six-week supplementation with 160 mg/day of a standardized extract of Ginkgo biloba or a matching placebo on aerobic performance, blood antioxidant capacity, and brain-derived neurotrophic factor (BDNF) level in healthy, physically active young men, randomly allocated to two groups (n = 9 each). At baseline, as well as on the day following the treatment, the participants performed an incremental cycling test for the assessment of maximal oxygen uptake. Venous blood samples taken at rest, then immediately post-test and following 1 h of recovery, were analyzed for activities of antioxidant enzymes and plasma concentrations of non-enzymatic antioxidants, total phenolics, uric acid, lipid peroxidation products, ferric reducing ability of plasma (FRAP), and serum brain-derived neurotrophic factor (BDNF). Our results show that six weeks' supplementation with Ginkgo biloba extract in physically active young men may provide some marginal improvements in their endurance performance expressed as VO₂max and blood antioxidant capacity, as evidenced by specific biomarkers, and elicit somewhat better neuroprotection through increased exercise-induced production of BDNF.

Cardiac hypertrophy and IGF-1 response to testosterone propionate treatment in trained male rats

Objective

Several studies have suggested that testosterone exerts a growth-promoting effect in the heart. Limited data are available regarding interactions between possible endocrine/paracrine effects in response to exercise training. Therefore, we examined supraphysiological testosterone-induced heart hypertrophy and cardiac insulin-like growth factor (IGF)-1 content in sedentary and exercise-trained rats.

Design

Male Wistar rats (n=33) were randomly allocated to groups with a 6-week endurance training with or without testosterone, and sedentary animals with or without testosterone. The hormone (20 mg/250 g body weight was administrated once a week for six weeks. After six weeks the animals were anesthetized, euthanized and the heart was excised and weighed. The left ventricle was separated for biochemical analyses.

Results

Testosterone-treated animals showed significantly higher cardiac IGF-1 content compared to untreated control and trained groups (p=0.01). The administration of supraphysiological testosterone significantly increased the heart weight to body weight ratio (HW/BW, p<0.01). A significant positive correlation was seen between IGF-1 levels and the HW/BW ratio (p=0.002; r=0.50) and between serum total testosterone levels and HW/BW (p=0.000; r=0.79).

Conclusions

The results demonstrate that increased cardiac IGF-1 content in response to higher serum testosterone might be responsible for heart hypertrophy observed in both sedentary and endurance-trained animals.

Associations of visceral fat area and physical activity levels with the risk of metabolic syndrome in postmenopausal women

This study was aimed at the evaluation of relationship between visceral fat area (VFA) and physical activity (PA) with the metabolic syndrome (MetS) risk in the physically active postmenopausal women. A total of 85 attendants of the University of the Third Age (U3A) aged 62.8 ± 5.9 years (median time since menopause 11.8 y), participated in this study. VFA was assessed by bioimpedance method using InBody 720 analyzer. PA was assessed using the ActiGraph GT1 M accelerometer. Fasting levels of serum lipids (TG, HDL), serum glucose, waist circumference (WC) and blood pressure were measured to diagnose MetS according to NCEP-ATP III criteria. In 73 out of 85 participants the VFA exceeded the upper normal level of 100 cm², however, in almost a half of this group (n = 36) with elevated VFA (139.5 ± 26.1 cm² on average), only 2 out of 5 criteria for MetS diagnosis were met. Participants were physically active, making on average 10,919 ± 3435 steps/day. The risk of MetS occurrence in women with VFA > 100 cm² was twelve times higher (OR 12.33; CI 95% [1.5; 99.8]) than in the group with VFA < 100 cm². The participants from the group with the highest PA level (≥12,500 steps/day) were at almost 4 times lower risk for MetS, than their less active counterparts (OR 3.84; CI 95% [1.27;11.64]). Increased level of VFA is a strong risk factor for the MetS in postmenopausal women, however high level of regular PA above the threshold of 12,500 steps/day may substantially reduce it.

Physical activity, body composition and general health status of physically active students of the University of the Third Age (U3A)

OBJECTIVE

To evaluate general health status of a group of older adults, physically active students of the University of the Third Age (U3A), based on results of biochemical analyses of blood, assessment of their physical activity (PA) level, body composition and cognitive function with respect to age and sex.

METHODS

A total of 104 students (85 women and 19 men, aged 63.7±6.6 y) of the U3A's located in the Upper Silesia region of Poland volunteered to participate in this study. A habitual PA level and body composition were objectively assessed by using ActiGraph GT1M and InBody 720, respectively. Serum lipid profile and glucose metabolism markers were measured for assessment of cardiovascular disease risk factors. Moreover, subjects' cognitive functions were tested.

RESULTS

Most of the study participants reached the daily step goal of 10,000 steps and thus fulfilled the ACSM recommendations for the quantity and quality of cardiorespiratory exercise. Highly negative correlations between the number of steps per day and body adiposity markers, serum insulin and HOMA-IR confirmed that vigorous physical activity at the recommended level was associated with better body composition and lower levels of risk markers of coronary heart disease and diabetes. Most of the U3A students were characterized by a favorable lipid profile, prevalence of normal blood pressure, low rates of HOMA-estimated insulin resistance and normal cognitive function.

CONCLUSION

Adherence to ACSM recommendations is associated with beneficial changes in risk factors related to cardiovascular disease.

Effects of Regular Recreational Exercise Training on Serum ANGPTL3-Like Protein and Lipid Profile in Young Healthy Adults

Evidence of the role of ANGPTL3, a liver-secreted glycoprotein, in serum lipid turnover, led us to hypothesize that this protein may be involved in modification of the lipid profile induced by exercise-training. Given the lack of data regarding this issue, the main goal of the present study was to investigate the effects of regular participation in a recreational physical activity program on serum ANGPTL3 and selected lipid profile measures in young, apparently healthy female and male adults. We compared serum ANGPTL3, lipid profile measures, common lipid ratios, the Atherogenic Index of Plasma (AIP) and glucose in fasting blood samples derived from 22 active physical education students including active females (AF, N=6) and males (AM, N=16) with samples from 28 relatively sedentary age-matched peers, including female (SF, N=9) and male (SM, N=19) individuals not involved in any regular physical conditioning program. Despite high inter-individual variability of serum ANGPTL3, there was a general tendency toward higher serum ANGPTL3 and HDL-C in women compared to men, but without significant differences related to their physical activity status. Based on both routine lipid profile measures and lipid ratios, all participants had normal lipid profiles, normal glycemia, as well as favorable anthropometric indices not suggesting increased cardiometabolic risk. However, lower levels of the TG/HDL-C ratio and AIP in physically active compared to relatively sedentary participants, reflecting the predominance of large, buoyant LDL particles, strongly support the view of beneficial health-promoting effects of regular participation in recreational sport activities.

Effects of supplementation with acai (Euterpe oleracea Mart.) berry-based juice blend on the blood antioxidant defence capacity and lipid profile in junior hurdlers. A pilot study

The purpose of this pilot study was to examine whether regular consumption of an acai berry-based juice blend would affect sprint performance and improve blood antioxidant status and lipid profile in junior athletes. Seven junior hurdlers (17.5±1.2 years) taking part in a pre-season conditioning camp were supplemented once a day, for six weeks, with 100 ml of the juice blend. At the start and the end of the camp the athletes performed a 300-m sprint running test on an outdoor track. Blood samples were taken before and immediately after the test and after 1 h of recovery. Blood antioxidant status was evaluated based on activities of antioxidant enzymes (superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GSH-Px], glutathione reductase [GR]), concentrations of non-enzymatic antioxidants (reduced glutathione [GSH], uric acid), total plasma polyphenols, ferric reducing ability of plasma (FRAP), thiobarbituric acid reactive substances (TBARS) and activities of creatine kinase (CK) and lactate dehydrogenase (LDH) as muscle damage markers. In order to evaluate potential health benefits of the acai berry, the post-treatment changes in lipid profile parameters (triglycerides, cholesterol and its fractions) were analysed. Six weeks’ consumption of acai berry-based juice blend had no effect on sprint performance, but it led to a marked increase in the total antioxidant capacity of plasma, attenuation of the exercise-induced muscle damage, and a substantial improvement of serum lipid profile. These findings strongly support the view of the health benefits of supplementation with the acai berry-based juice blend, mainly attributed to its high total polyphenol content and the related high in vivo antioxidant and hypocholesterolaemic activities of this supplement.

Acute metabolic responses to a 24-h ultra-marathon race in male amateur runners

The study was conducted to evaluate the metabolic responses to a 24 h ultra-endurance race in male runners. Paired venous and capillary blood samples from 14 athletes (mean age 43.0 ± 10.8 years, body weight 64.3 ± 7.2 kg, VO(2max) 57.8 ± 6.1 ml kg(-1) min(-1)), taken 3 h before the run, after completing the marathon distance (42.195 km), after 12 h, and at the finish of the race, were analyzed for blood morphology, acid-base balance and electrolytes, lipid profile, interleukin-6 (IL-6), high-sensitivity C-reactive protein (hsCRP), and serum enzyme activities. Mean distance covered during the race was 168.5 ± 23.1 km (range 125.2-218.5 km). Prolonged ultra-endurance exercise triggered immune and inflammatory responses, as evidenced by a twofold increase in total leukocyte count with neutrophils and monocytes as main contributors, nearly 30-fold increase in serum IL-6 and over 20-fold rise in hsCRP. A progressive exponential increase in mean creatine kinase activity up to the level 70-fold higher than the respective pre-race value, a several fold rise in serum activities of aspartate aminotransferase and alanine aminotransferase, and a fairly stable serum γ-glutamyl transferase level, were indicative of muscle, but not of liver damage. With duration of exercise, there was a progressive development of hyperventilation-induced hypocapnic alkalosis, and a marked alteration in substrate utilization towards fat oxidation to maintain blood glucose homeostasis. The results of this study may imply that progressive decline in partial CO(2) pressure (hypocapnia) that develops during prolonged exercise may contribute to increased interleukin-6 production.

Bioaccumulation of Germanium by Pseudomonas putida in the Presence of Two Selected Substrates

The uptake of germanium by Pseudomonas putida ATCC 33015 was studied in the presence of catechol or acetate or both as representative substrates differing in their ability to form complexes with this element. The bacteria were taken from a batch culture grown on acetate as the sole carbon source. Cells introduced into a medium containing germanium and either catechol or a mixture of catechol and acetate accumulated germanium in a biphasic way. After a lower level of accumulation that corresponded to the value obtained in the presence of acetate was reached, a further increase in the germanium content up to a higher saturation level was observed. The appearance of the second step of accumulation, which corresponded to the linear degradation of catechol, proved that catechol facilitated the transport of germanium into the cells through the nonspecific uptake of the germanium-catechol complex by an inducible catechol transport system.

Short-term effects of electrically induced tachycardia on antioxidant defenses in the normal and hypertrophied rat left ventricle

Increased oxidative stress resulting from enhanced production of reactive oxygen species and/or inadequate mechanisms of antioxidant defenses has been recognized as an important factor contributing to the initiation and progression of cardiac dysfunction under a wide variety of pathophysiological conditions. The main objective of this study was to examine the effect of electrically induced tachycardia on oxidative stress and the capacity of antioxidant defenses in the normal and hypertrophied left ventricle (LV) in the rat. Left ventricular hypertrophy (LVH) was produced by banding the descending abdominal aorta. The activities of antioxidant enzymes, concentrations of non-enzymatic antioxidants, and biomarkers of oxidative stress were measured in the LV of aortic-banded animals (LVH), untreated or banded rats subjected to short-term (45 min) atrial pacing [(CTR + S) and (LVH + S), respectively], and untreated (CTR) or sham-operated (SHAM) controls. The results indicate that the increase in heart rate in vivo as a result of atrial pacing to a maximum level, independent of sympathetic nerve activity, leads to a substantial increase in oxidative stress and a marked decline in the activities of antioxidant enzymes in both the normal and hypertrophied left ventricle of the rat. The accompanying increase in tissue content of alpha- and gamma-tocopherols seem to contribute to attenuation of the oxidant stress-related loss of thiol stores in the LV. Stable left ventricular hypertrophy induced by aortic banding for six weeks has a minor impact on the capacity of the endogenous antioxidant defense system in the LV, but significantly and negatively affects the ability of the heart LV to tolerate the stress of tachycardia.

Effects of castration and testosterone replacement on the antioxidant defense system in rat left ventricle

There is strong evidence that oxidative stress plays a key role in the pathophysiology of several cardiovascular diseases. On the other hand, the presence of specific receptors for androgens and estrogens in the myocardium implies that sex hormones play a physiological role in cardiac function, myocardial injury, and the regulation of the redox state in the heart. The present study was designed to determine whether castration and androgen replacement result in changes in the capacity of the antioxidant defense system in the left ventricle (LV) of adult male rats. To assess this, the activities of antioxidant enzymes (superoxide dismutase [SOD], glutathione peroxidase [GPX], catalase [CAT], and glutathione reductase [GR]), concentrations of nonenzymatic antioxidants (reduced glutathione [GSH] and alpha- and gamma-tocopherols), and oxidative stress biomarkers (tissue sulfhydryl groups, protein nitrotyrosine levels, and lipid peroxidation) were measured in castrated animals (CAS), castrates replaced with testosterone (CAS+T), and sham-operated controls (Sham). Testosterone was not detectable in serum from gonadectomized rats. The results indicate that castration significantly and negatively affected the antioxidant status of rat LV, as evidenced by a significant decline in activities of all antioxidant enzymes, by a tendency toward lower levels of GSH and protein thiol groups, and by enhanced lipid peroxidation and higher nitrotyrosine concentrations in left ventricular tissue. Increases in LV tissue concentrations of alpha- and gamma-tocopherols seem to be a compensatory response to enhanced oxidative stress induced by gonadectomy. The reestablishment of physiological serum testosterone level by androgen replacement resulted in a tendency toward a further decrease in the antioxidant defense status in the LV tissue.

Evaluation of Autoantibodies Against Oxidized LDL (oLAB) and Blood Antioxidant Status in Professional Soccer Players

Low-density lipoproteins (LDL) are very sensitive to oxidative processes initiated by oxygen free radicals, known to be produced in large quantities during intense physical exercise. Oxidatively modified lipoprotein particles (oxLDL) are strongly atherogenic and immunogenic, as a consequence specific autoantibodies (oLAB) against oxLDL are produced by the immune system. This study was designed to evaluate the oLAB titres in professional soccer players and to find out whether the immune response to oxidative modification of LDL correlates with the antioxidant status of individual players. Eleven players volunteered to participate in an incremental treadmill running exercise to volitional fatigue twice (in October and January) during the competitive season. Venous blood samples were withdrawn before and 3 min after the cessation of the test. Serum levels of oLAB were measured by ELISA (Biomedica). Blood samples were analyzed for glutathione peroxidase, reduced glutathione, superoxide dismutase, catalase and glutathione reductase. The activity of creatine kinase (CK) and concentrations of malondialdehyde (MDA), vitamin E and retinol were determined in plasma. From 11 subjects only in 4 players, in both graded running tests, the oLAB titres were low (< 200 mU.ml(-1)). The remaining athletes presented elevated oLAB (800-1400 mU.ml(-1)). Significantly lower activities of catalase and glutathione reductase and lower concentration of alpha-tocopherol were recorded in the 2nd trial. When the data were arranged according to the oLAB titres no significant between-group differences were found in either pre- and post-test activities of antioxidant enzymes or in concentrations of antioxidants. However, significantly higher CK activities and a tendency towards more elevated plasma MDA concentrations were observed in subjects with higher oLAB levels. It seems justified to presume that high titres of antibodies against oxLDL, as evidenced in most of the players, could be accounted for by their higher in vivo susceptibility of LDL to structural modification under conditions of intensive training-induced oxidative stress, despite their apparently normal antioxidant status.

Selenium levels in blood of upper Silesian population: evidence of suboptimal selenium status in a significant percentage of the population

The selenium status and the relationship of whole-blood selenium and plasma homocysteine are reported for healthy human subjects living in Upper Silesia. A total of 1063 individuals (627 male and 436 female) examined for whole-blood selenium were subdivided into six groups according to age; the youngest included adolescents (n=143) aged 10-15 yr, and the oldest were centenarians (n=132). The mean Se content was relatively low (62.5+/-18.4 microg/L), and it tended to be higher in men (65.9+/-17.2 microg/L) than in women (57.5+/-18.9 microg/L). Selenium levels appeared to be age dependent, as the highest values were observed in young and middle-age adults (21-40 yr), whereas they were significantly lower in adolescents and in the elderly. In more than 40% of apparently healthy adults (aged 21-69 yr), the Se concentration was within the range 60-80 microg/L (i.e., below the lower limit of the nutritional adequacy range [80 microg/L]). A significant inverse correlation between whole-blood selenium and plasma total homocysteine was detected in a smaller population sample of middle-aged and elderly persons (n=204).

Antioxidant status in newborns and infants suffering from congenital heart defects

There is a common view that free radicals may play an important role in tissue damage resulting from circulatory insufficiency, cardiosurgery etc. There are very few data concerning the involvement of free radical reactions in the newborns and infants suffering from congenital heart defects (CHD). Antioxidant status was evaluated in 41 newborns and infants under 1 year of age, among them 23 suffering from CHD (14 with left-to-right shunt and 9 with cyanotic heart defect) and 18 healthy controls. The study based on the assessment of activities of antioxidant enzymes in blood (superoxide dismutase, catalase and glutathione peroxidase), levels of low molecular weight antioxidants (vitamin E, uric acid and selenium) and the concentration of malondialdehyde (MDA) as a marker of lipid peroxidation. All subjects had low blood selenium concentration as compared to the level considered as being adequate. Infants suffering from CHD had lower, as compared to healthy controls, plasma vitamin E concentration. The difference was significant in the case of acyanotic ones. The activities of superoxide dismutase and catalase in infants with CHD were not significantly different from the respective values recorded in healthy controls. The activity of glutathione peroxidase in whole blood was the lowest in infants with cyanotic heart defect in whom lipid peroxidation, as evaluated by MDA level, was the most enhanced. Significantly higher plasma concentration of uric acid which may be interpreted as a positive mechanism enabling better protection of red blood cells from peroxidative damage was found in this group of infants. It is concluded that enhanced oxidative stress due to imbalance between prooxidant and antioxidant reactions appears to be associated with congenital heart defect pathology in infants.

Effects of a low carbohydrate diet and graded exercise during the follicular and luteal phases on the blood antioxidant status in healthy women

The aim of this study was to examine the effect of a low-carbohydrate (L-CHO) diet and graded cycling exercise on the enzymatic and non-enzymatic blood antioxidant defence system in young eumenorrhoeic women. Seven healthy physical education students exercised incrementally until they were fatigued under four different phase-diet conditions of the menstrual cycle, i.e. twice either during the mid-follicular or the mid-luteal phase, in each case either after 3 days of eating a normal mixed diet (59% carbohydrate, 27% fat, 14% protein) or 3 days of eating an isoenergy L-CHO diet (5% carbohydrate, 52% fat, 43% protein). In venous blood samples obtained at rest, immediately post test and during recovery, the activity of antioxidant enzymes and concentrations of reduced glutathione and selenium were determined. Plasma samples were analysed for concentrations of malondialdehyde, vitamin E (alpha-tocopherol), uric acid and activity of creatine kinase. The 3 days of the L-CHO diet, which had been preceded by glycogen-depleting exercise, resulted in a stimulation of the blood antioxidant defence system in young eumenorrhoeic women both at rest and during the graded cycling exercise to maximal oxygen uptake. It seems justified to presume that higher daily doses of haem iron, selenium and alpha-tocopherol provided by the L-CHO diet contributed to the enhancement of catalase activity, the rise in plasma concentrations of alpha-tocopherol and selenium, which resulted in better protection of the cell membranes against damage from peroxides, as reflected by a limited release of creatine kinase into plasma. With the exception of the case of glutathione reductase, the phases of the menstrual cycle had only minor effects on the indices of the blood antioxidant defence system.

Antioxidant defense in centenarians (a preliminary study)

The study was designed to assess the antioxidant defense mechanisms, either enzymatic or non-enzymatic, in a group of sixteen centenarians (one male and fifteen female subjects aged 101 to 105 years) living in the Upper Silesia district (Poland) in order to evaluate the potential role of antioxidant defenses in human longevity. The results of our preliminary study showed that in comparison with young healthy female adults the centenarians had significantly higher red blood cell glutathione reductase and catalase activities and higher, although insignificantly, serum vitamin E level.

Antioxidant defense in centenarians (a preliminary study)

The study was designed to assess the antioxidant defense mechanisms, either enzymatic or non-enzymatic, in a group of sixteen centenarians (one male and fifteen female subjects aged 101 to 105 years) living in the Upper Silesia district (Poland) in order to evaluate the potential role of antioxidant defenses in human longevity. The results of our preliminary study showed that in comparison with young healthy female adults the centenarians had significantly higher red blood cell glutathione reductase and catalase activities and higher, although insignificantly, serum vitamin E level.

Binding of germanium and lead to Pseudomonas putida lipopolysaccharides

The binding of germanium and lead ions to lipopolysaccharide isolated from Pseudomonas putida ATCC 33015 was studied by high-resolution 31P nuclear magnetic resonance spectroscopy. Chemical shift changes toward higher field as well as broadening of all phosphorus resonances were observed with added lead. Addition of germanium to the lipopolysaccharide sample resulted in more pronounced chemical shift changes toward lower field. The effects of binding of germanium and lead ions on the 31P nuclear magnetic resonance spectrum of lipopolysaccharide imply that the glycosidic monophosphate joined to the reducing end of N-acetylglucosamine (C-1 position of α-D-G1cNI) as well as β-phosphate groups of glycosidically linked diphosphates of the same residue of the lipid A moiety provide high-affinity metal-binding sites.Key words: germanium, lead, lipopolisaccharide (LPS), binding, Pseudomonas putida.

Binding of Germanium to Pseudomonas putida Cells

The binding of germanium to Pseudomonas putida ATCC 33015 was investigated by using whole intact cells grown in a medium supplemented with GeO 2 and catechol or acetate. Electron-microscopic examination of the control and metal-loaded samples revealed that germanium was bound within the cell envelope. A certain number of small electron-dense deposits of the bound element were found in the cytoplasm when the cells were grown in the presence of GeO 2 and catechol. The study of germanium distribution in cellular fractions revealed that catechol facilitated the intracellular accumulation of this element.