Daily copper supplement effects on copper balance in trained subjects during prolonged restriction of muscular activity.

The aim of this study was to assess the effect of a daily intake of copper supplements on negative copper balance during prolonged exposure to hypokinesia (decreased number of kilometers per day). During hypokinesia (HK), negative copper balance is shown by increased, not by decreased, serum copper concentration, as it happens in other situations. Studies were done during a 30-d prehypokinetic period and a 364-d hypokinetic period. Forty male trained volunteers aged 22-26 yr with a peak oxygen uptake of 66.4 mL/min/kg and with an average of 13.7 km/d running distance were chosen as subjects. They were equally divided into four groups: unsupplemented ambulatory control subjects (UACS), unsupplemented hypokinetic subjects (UHKS), supplemented hypokinetic subjects (SHKS), and supplemented ambulatory control subjects (SACS). The SACS and SHKS groups took 0.09 mg copper carbonate/kg body weight daily. The SHKS and UHKS groups were maintained under an average running distance of 1.7 km/d, whereas the SACS and UACS groups did not experience any modifications in their normal training routines. During the 30-d prehypokinetic period and the 346-d hypokinetic period, urinary excretion of copper, calcium, and magnesium and serum concentrations of copper, calcium, and magnesium were measured. Copper loss in feces and copper balance was also determined. In both UHKS and SHKS groups, urinary excretion of copper, calcium, and magnesium and concentrations of copper, magnesium, and calcium in serum increased significantly when compared with the SACS and UACS groups. Loss of copper in feces was also increased significantly in the SHKS and UHKS groups when compared with the UACS and SACS groups. Throughout the study, the copper balance was negative in the SHKS and UHKS groups, whereas in the SACS and UACS groups, the copper balance was positive. It was concluded that a daily intake of copper supplements cannot be used to prevent copper deficiency shown by increased copper concentration. Copper supplements also failed to prevent negative copper balance and copper losses in feces and urine in endurance-trained subjects during prolonged exposure to HK.

Daily hyperhydration effect on electrolyte deficiency of endurance-trained subjects during prolonged hypokinesia.

The aim of this study was to evaluate the effect of a daily intake of fluid and salt supplementation (FSS) on the deficiency of electrolytes, which is characterized by higher rather than lower plasma concentration of electrolytes during prolonged hypokinesia (HK) (decreased number of km taken per day). Forty long distance runners aged 22-25 yr with a peak VO2 65.4 mL min(-1) kg(-1) with an average 14.2 km d running distance were selected as subjects. They were equally divided into four groups: 1) unsupplemented control subjects (UCS); 2) unsupplemented hypokinetic subjects (UHS); 3) supplemented hypokinetic subjects (SHS), and 4) supplemented control subjects (SCS). During the investigation of 364 d, groups 2 and 3 maintained an average running distance of less than 4.7 km per day, groups 1 and 4 did not experience any modification in their normal training routines and diets. During the preexperimental period of 60 d and during the experimental period of 364 d urinary excretion of electrolytes and concentrations of sodium, potassium, calcium, and magnesium in plasma were determined. Whole blood hemoglobin, hematocrit index, plasma osmolality, and plasma protein concentration were measured. In the UHS plasma concentration of electrolytes and urinary excretion thereof, fluid elimination, hematocrit, whole blood hemoglobin, plasma osmolality, and plasma protein concentration increased significantly (p < 0.05) when compared with the UCS, SCS, and SHS groups. In the SHS plasma concentration of electrolytes and urinary excretion thereof, fluid excretion, whole blood hemoglobin, hematocrit, plasma osmolality, and plasma protein concentration decreased when compared with the UHS and increased insignificantly when compared with the UCS and SCS groups. It was concluded that FSS may be used to prevent or minimize electrolyte deficiency in endurance-trained volunteers during prolonged restriction of muscular activity.

Magnesium loading effect on magnesium deficiency in endurance-trained subjects during prolonged restriction of muscular activity.

The aim of this study was to evaluate the effect of magnesium (Mg) loading (10.0 mg Mg/kg body wt) and daily Mg supplements (5.0 mg Mg/kg body wt) on Mg deficiency shown by increased and not by decreased serum Mg concentration during hypokinesia (decreased km number/d). The studies were done during 30 d of prehypokinesia and 364 d of hypokinesia (HK) periods. Forty endurance-trained volunteers aged 22-26 yr with a peak VO2 max of 66.3 mL.kg-1 min-1 and with an average 15.0 km/d running distance were chosen as subjects. They were equally divided into four groups: 1. Unsupplemented ambulatory control subjects (UACS). 2. Unsupplemented hypokinetic subjects (UHKS). 3. Supplemented hypokinetic subjects (SHKS). 4. Supplemented ambulatory control subjects (SACS). The SHKS and SACS groups took daily 5.0 mg elemental Mg/kg body wt and subjected to Mg loading (10.0 mg Mg/kg body wt). Both the SHKS and UHKS groups were maintained under an average running distance of 4.7 km/d, whereas the SACS and UACS groups did not experience any modifications to their normal training routines and diets. During the prehypokinetic and hypokinetic periods, excretion of Mg in feces and urine, concentration of Mg in serum, and Mg balance were measured. Urinary and serum sodium (Na), potassium (K), and calcium (Ca) were also determined. In both SHKS and UHKS groups, fecal Mg loss, urinary excretion of electrolytes, and serum concentrations of electrolytes increased significantly (p < or = 0.05) when compared with the SACS and UACS groups. During Mg loading tests, urinary and fecal Mg excretion was also greater in the SHKS and UHKS groups than in the SACS and UACS groups. Throughout the study, Mg balance was negative in the SHKS and UHKS groups, whereas in the SACS and UACS groups, Mg balance was positive. It was concluded that significant losses of Mg occurred in the presence of negative Mg balance and Mg deficiency in endurance-trained subjects during prolonged exposure to HK, daily mg supplements, and Mg loading tests. This suggests that Mg is not entering or being retaining by the bones and cells of many tissues where most Mg is deposited normally, resulting in Mg deficiency as was shown by the increased serum Mg concentration.

Water and electrolyte excretion in rats during prolonged restriction of motor activity and chronic hyperhydration.

The objective of this investigation was to evaluate the effect of daily intakes of water and salt on water and electrolyte changes and body hydration status of rats during prolonged restriction of motor activity (hypokinesia). Ninety Wistar rats weighing 370 to 390 g were used to perform the studies: They were equally divided into three groups: 1. Unsupplemented vivarium control rats (UVCR); 2 Unsupplemented hypokinetic rats (UHKR) and 3. Supplemented hypokinetic rats (SHKR). For the simulation of the effect of hypokinesia (HK), the UHKR and SHKR groups were kept in small individual cages made of wood, which restricted their movements in all directions without hindering food and water intake. The SHKR received daily an additional amount of 5 ml water/100 g body weight and 3 g sodium chloride per 100 g body weights. During the prehypokinetic period of 15 days and during the hypokinetic period of 90 days plasma and urinary sodium and potassium, water intake and water loss, food intake, body weight, plasma osmolality, whole blood hemoglobin, hematocrit and plasma protein concentration were determined. In the UHKR group, plasma and urinary electrolytes, diuresis, plasma osmolality, whole blood hemoglobin, hematocrit and plasma protein concentration increased significantly while fluid and food intake and body weight decreased significantly when compared with the SHKR and UVCR groups. In the SHKR, plasma and urinary electrolytes, urine excretion, plasma osmolality, whole blood hemoglobin, hematocrit and plasma protein concentration decreased while food and water intake and body weight increased significantly when compared with the UHKR group. In the UVCR group, these same variables remained stable or changed very little when compared with the SHKR group throughout the experimental period. It was concluded that daily intakes of fluid and a salt supplement may be used to increase body hydration level and decrease fluid-electrolyte excretion and body weight losses during prolonged restriction of motor activity.

Fluid electrolyte changes during prolonged restriction of motor activity in rat.

Water and electrolyte changes in urine and plasma of rats during prolonged restriction of motor activity (hypokinesia), have been studied, on 90 male Wistar rats (375 to 396 g) during a 15 day period of prehypokinesia and during a 90 day period of hypokinesia (HK). All rats were divided equally into two groups: rats placed under ordinary vivarium conditions served as vivarium control rats (VCR) and rats subjected to HK served as hypokinetic rats (HKR). The hypokinetic effect was carried out by keeping the HKR group in small individual cages that restricted all their movements in all directions without hindering food and water intake. During the 15 days of the prehypokinetic period and during the 90 days of the hypokinetic period, fluid consumed and eliminated in urine, food intake, body weight, plasma sodium and potassium concentration and excretion thereof in urine, plasma osmolality, total protein plasma concentration, whole blood haemoglobin and haematocrit concentration were measured. In the HKR group water and food intakes decreased significantly (p < 0.05) when compared with the VCR group, whilst diuresis, excretion of sodium and potassium in urine, plasma sodium and potassium concentration, plasma osmolality, plasma protein concentration, whole blood haemoglobin and haematocrit increased significantly (p < or = 0.05) when compared with the VCR group. It was concluded that prolonged exposure to HK induces significant changes in water balance and in both urinary and plasma sodium and potassium in rat.

Daily magnesium supplementation effect on magnesium deficiency in rats during prolonged restriction of motor activity.

The objective of this investigation was to evaluate the effect of magnesium (Mg) supplements in rats during prolonged restriction of motor activity (hypokinesia [HK]) and in the presence of Mg deficiency, which is characterized by increased rather than decreased plasma Mg concentration, as occurs in ambulatory conditions. The studies were performed during 98 days of HK on 100 13-week-old Sprague-Dawlay male rats weighing 360 to 390 g. They were equally divided into four groups: (1) unsupplemented control animals (UCA), (2) unsupplemented hypokinetic animals (UHA), (3) supplemented control animals (SCA), and (4) supplemented hypokinetic animals (SHA). For the simulation of the hypokinetic effect, SHA and UHA were kept for 98 days in small individual wood cages that restricted their movements in all directions without hindering food and water intake. The SCA and SHA took daily with their food an additional 0.35 mg of Mg. Before and during the hypokinetic period of 98 days, Mg in plasma, urine, and feces, balance of Mg, food intake of Mg, and body weight were determined at different intervals. In SHA and UHA, plasma Mg concentration and excretion of Mg in urine and feces increased significantly compared with SCA and UCA. Magnesium balance was negative in UHA and AHA throughout the hypokinetic period. Body weight and a food intake decreased significantly in SHA and UHA when compared with SCA and UCA. Significant losses of Mg in SHA and UHA occurred in the presence of Mg deficiency and suggest that prolonged HK induces another factor that influences Mg metabolism. We conclude that prolonged HK causes significant changes in Mg values of plasma, urine, and feces and a negative Mg balance in rats, despite Mg supplements leading to Mg deficiency.

Changes in thyroid hormones and lipids in endurance trained volunteers during acute and rigorous bed rest conditions.

The aim of this study was to evaluate the effect of an acute rigorous bed rest (ABR) (abrupt confinement to a rigorous bed rest regimen) and a rigorous bed rest (RBR) regimen on serum concentrations of thyroid hormones and lipids. The studies were done during seven days of a pre bed rest period and during seven days of an ABR and RBR period. Thirty endurance trained male volunteers aged 22 to 26 years with a peak oxygen uptake of 66.0 mL.min-1.kg-1 and running an average of 14.0 km.day-1 were chosen as subjects. They were divided equally into three groups: (one) ten athletes placed under ambulatory conditions served as ambulatory control subjects (ACS), (two) ten athletes subjected to an acute rigorous bed rest regimen served as acute bed rested subjects (ABRS) and (three) ten athletes submitted to a rigorous bed rest regimen served as rigorous bed rested subjects (RBRS). For the simulation of the effect of ABR the ABRS group was submitted abruptly to a rigorous bed rest regimen. They did not have any prior knowledge of the exact date and time when they would be asked to submit to the RBR. For the simulation of the effect of RBR the RBRS group was subjected to a rigorous bed rest regimen on a predetermined date and time known to them right from the start of the study. During the pre bed rest period and during the ABR and RBR periods serum concentrations of thyroxine (T3), triiodothyronine (T4), thyroid-stimulating hormone (TSH), cholesterol, triglycerides, total protein and albumin were measured. In the ABRS and RBRS groups serum concentrations of T3, T4, TSH, cholesterol, triglycerides, total protein and albumin increased significantly when compared with the ACS group. Serum concentrations of thyroid hormones and lipids in the ABRS group increased much faster and were more pronounced than in the RBRS group. It is concluded that exposure to RBR and, especially, to ABR conditions induces significant increases in serum concentrations of thyroid hormones and lipids. These changes occurred much earlier and were much greater in the ABRS group than in the RBRS group.

Bone tissue changes in rats during prolonged restriction of motor activity.

The objective of this investigation was to measure the effect of prolonged restriction of motor activity (hypokinesia) of rats on the mass, density, mineral composition, reconstruction parameters and elemental composition of their bone tissue. The studies were done during 90 days of hypokinesia (HK) on 90 male Wistar rats equally divided into two groups: (1) vivarium control rats (VCR) and (2) hypokinetic rats (HKR). For the simulation of the hypokinetic effect the HKR group was kept for 90 days in small individual cages made of wood that restricted the movements of rats in all directions without hindering food and water intakes. During the prehypokinetic period of 15 days and during the hypokinetic period of 90 days bone mass, bone density, bone calcium and phosphorus concentrations, bone reconstruction parameters and elemental composition of bones were determined. During the same periods food intake and body weight losses were also measured. In the HKR group signs of osteoporosis in the spongy structures of the tubular bones were observed; they also showed significant decrease in rat femur weight, and in cross section of the rat femur, and in mineral concentrations of the femoral head when compared with the VCR group. The HKR group also show a significant decrease in food intake and body weight when compared with the VCR group. The corresponding parameters did not change significantly in the VCR group when compared with the baseline control values. It was concluded that prolonged exposure to HK induced osteoporosis and structural changes in bones. This apparently occurred due to inhibition of bone tissue formation in the HKR group.

Daily zinc supplementation effect on zinc deficiency in rats during prolonged restriction of motor activity.

The objective of this investigation was to evaluate the effect of 47 mg zinc supplementation on deficiency of zinc in rats during 98 d of restriction of motor activity (hypokinesia), which appeared by higher plasma zinc concentration. One Hundred 13-week-old Sprague-Dawley male rats weighing 360-390 g were used to perform the studies: They were equally divided into four groups: 1. Unsupplemented control animals (UCA); 2. Unsupplemented hypokinetic animals (UHA); 3. Supplemented control animals (SCA); and 4. Supplemented hypokinetic animals (SHA). For the simulation of the effect of hypokinesia (HK), the UHA and SHA were kept in small individual cages made of wood, which restricted their movements in all directions without hindering food and water intake. The SCA and SHA received daily with their food an additional amount of zinc. Before and during the experimental period of 98 d, plasma, urinary and fecal zinc, balance of zinc, food intake, and body weight were determined at different intervals. In the SHA and UHA, the concentration of zinc in plasma, and the elimination of zinc in urine and feces increased significantly when compared with the SCA and UCA, whereas the balance of zinc was negative. The body weight and food intake decreased significantly in the SHA and UHA when compared with the SCA and UCA. The increased plasma concentration of zinc in both the SHA and UHA groups was in contrast to the observed hypozincnemia during prolonged immobilization as during prolonged hospitalization. This reaction suggests that there may be some other mechanisms that are affecting the process of control and regulation of zinc metabolism during prolonged HK. It was concluded that exposure to prolonged restriction of motor activity of rats induces significant increases in plasma concentration, fecal and urinary elimination of zinc in the presence of negative zinc balance and regardless the daily intake of large amounts of zinc with their food, leading to zinc deficiency.

Electrolyte concentration in skeletal muscles and plasma of rats during and after exposure to hypokinesia and hyperhydration.

The objective of this investigation was to determine electrolyte concentration in skeletal muscles and plasma of rats during 90 days of hypokinesia (decreased motor activity) and 15 days of posthypokinesia. The animals were divided into three groups: 1) supplemented hypokinetic rats (SHR), i.e., rats subjected to hypokinesia and taking daily an additional 9 ml water per 100 g body weight plus 6 ml isotonic sodium chloride per 100 g body weight; 2) unsupplemented hypokinetic rats (UHR), i.e., rats subjected to hypokinesia; 3) vivarium control rats (VCR), i.e., rats placed under ordinary vivarium conditions. Hypokinesia was effected by keeping SHR and UHR animals in small individual cages that restricted their movements in all directions without hindering food and water intake. Determinations were made of water and electrolyte (sodium potassium, calcium, magnesium) concentrations in muscle tissue; concentration of electrolytes (sodium, potassium, calcium, magnesium, phosphorus, chloride) in plasma; body weight; fluid consumed and eliminated in urine; whole blood, red blood cell and plasma volumes; hematocrit content and plasma protein concentration. During the hypokinetic period, electrolytes and water concentration in muscle tissue and plasma electrolyte concentration changes significantly in the UHR when compared with SHR and VCR while in comparing the SHR with the VCR these same variables had no significant changes. Body weight, water balance, volume of blood, red blood cell and plasma, hematocrit and plasma protein concentration in the UHR were also significantly different when compared with the VCR. No significant difference was seen in these parameters when the SHR and VCR were compared. During the initial seven days of the posthypokinetic period the changes in these same parameters remained significantly different in the UHR when compared with the SHR and VCR while changes were insignificant when the SHR and the VCR were compared. It was concluded that daily hyperhydration may be used to attenuate or normalize water and electrolyte concentrations in muscles and plasma of rats subjected to prolonged restriction of motor activity.

Bone histomorphometric changes in trained subjects during prolonged restriction of muscular activity and chronic hyperhydration.

BACKGROUND: The purpose of this study was to determine whether histomorphometric changes, which are developed during prolonged hypokinesia (decreased number of km/day) could be prevented or minimized with a daily intake of fluid and salt supplementation (FSS). METHODS: The studies on hypokinesia (HK) were performed for 364 days on thirty endurance trained male volunteers (ETV) in the age of 19 to 25 years, with an average peak oxygen uptake (POU), of 65 mL/kg-1.min-1. All volunteers were divided into three equal groups: ten volunteers were placed on a continuous regime of exercise of 13.8 km/day and served as control subjects. Ten volunteers were subjected to continuous HK without FSS and were considered as the unsupplemented hypokinetic subjects (UHS). The remaining volunteers were under continuous HK and FSS and were considered as the supplemented hypokinetic subjects (SHS). For the simulation of the hypokinetic effect, the SHS and UHS groups were kept continuously under an average of 2.7 km/day for the duration of the experiment. Prior to exposure to HK, all volunteers were on the same exercise regime as the control subjects. During the 60 day pre-HK period and during the experimental period, the following parameter were determined: sodium and calcium in urine and plasma, hemoglobin (Hb), hematocrit (Hct), plasma osmolality, plasma protein concentration, plasma renin activity, aldosterone and parathyroid hormone (PTH) concentration. RESULTS: In the UHS iliac crest cancellous bone volume and PTH content decreased, urinary and plasma electrolytes, plasma renin activity, aldosterone, plasma osmolality, protein content, Hb and Hct increased significantly. In the SHS iliac crest cancellous bone volume and PTH content increased, while electrolytes in urine and plasma Hb, Hct, osmolality, protein, aldosterone and plasma renin activity decreased. CONCLUSIONS: It was concluded that daily intake of FSS may be used to minimize or prevent histomorphometric changes in endurance trained volunteers during exposure to prolonged HK.

[A centering guide for the gamma camera]. / Tsentrator dlia gamma-kamery.

A device for centering a gamma-camera indicator is described. It permits the use of available medical coaches instead of a table with a transparent top. The device can be used for centering an indicator (when it is fixed at the low end of a gamma-camera) on a required area of the patient's body.

[A device for centering a gamma camera transducer]. / Ustroistvo dlia tsentratsii datchika gamma-kamery.

The device consists of the upper part of the gamma chamber pillar to which a rod is rigidly fastened with a disk of acrylic plastic moving freely on the opposite end. This disk is placed coaxially and is equal to the gamma chamber detector crystal. The device makes it possible to use ordinary medical couches covered with a porolone mattress when the gamma chamber detector is placed below.