Biomedical subjects

V Vihko

Publications and source records attributed to V Vihko.

At least 37 records · Page 2Linked to original sources

PubMed1994

Running-induced muscle injury and myocellular enzyme release in rats.

The relationships and time course of exercise-induced muscle damage, estimated by beta-glucuronidase activity and microscopy, to muscle swelling, estimated by muscle water content and microscopy, and to the serum activity of creatine kinase (CK) and the concentration of carbonic anhydrase III were studied in rats 2, 12, 48, and 96 h after 90 min of intermittent running uphill (+13.5 degrees) or downhill (-13.5 degrees) at a speed of 17 m/min. The injury was more pronounced in soleus after uphill running and in the red parts of quadriceps femoris and in the white part of vastus lateralis after downhill running, whereas triceps brachii was not damaged. Increase in muscle water content preceded the increase of beta-glucuronidase activity. Both running protocols similarly increased serum CK 2 h postexercise. After downhill running a second peak in serum CK was observed 48 h later. The CK changes were not in concert with the changes in muscle water content or beta-glucuronidase activity, suggesting that these responses may not be mechanistically (or causally) related.

Animals↗

PubMed1993

Life-long physical activity and cancer risk among Finnish female teachers.

This cohort study on Finnish female teachers of physical education (PE) and languages (L) was performed as an attempt to evaluate the importance of physical activity as a risk determinant of cancer, PE representing a physically active and L a less active subcohort. All the PE and L teachers graduating from 1920 onwards were obtained from four registers compiled from 1958-73 supplemented by an extension cohort drawn from the union membership register 1984-91 (in total 1,499 PE and 8,619 L teachers). Results of a questionnaire to representative samples of L and PE teachers did not reveal any major intergroup differences in social status, general health status, nutrition, maturation history, reproductive history, consumption of alcohol, smoking, or diet. However, the PE teachers reported higher life-long physical activity values than the L teachers. During the follow-up period 1967-91, the number of cancer cases totalled 108 for the PE and 513 for the L teachers. Expected numbers of cancer cases were calculated on the basis of national incidence figures, and the standardized incidence ratios (SIRs) were defined as ratios of observed and expected numbers of cases. The SIR for total cancers was 1.1 for the PE and 1.2 for the L teachers. In both teacher groups the SIRs for cancers of the breast, endometrium, ovary and colon were similarly elevated and the SIR for cervical cancer was reduced. There was an increased SIR for lung cancer (1.4) and skin melanoma (2.0) in the PE but not in the L teachers (0.5 and 0.9, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗

PubMed1992

Effects of physical training, methandione and their combination on the lysosomal hydrolytic activities in dog heart.

The effects of endurance training, anabolic steroid (methandione 1.5 mg/kg p.o. daily) and their combination on the activities or aryl sulphatase, B-glucuronidase and cathepsin D, all lysosomal hydrolytic enzymes, were studied in the heart of male beagle dogs. Training caused significant increase in the B-glucuronidase activity in the right ventricular wall. Anabolic steroid as such caused no change in any enzymic activities, whereas exercise combined with steroid treatment resulted in significant increases in the activities of all enzymes studied in the right ventricular wall. The combined effect of exercise training and anabolic steroid on the lysosomal hydrolytic enzymes may reflect and mediate the previous observed degenerative effects of this combination in the heart.

Anabolic Agents↗

PubMed1991

Effects of training and anabolic steroids on collagen synthesis in dog heart.

The effects of endurance training and anabolic steroid (Methandienone 1.5 mg.kg-1 p. o. daily) and their combination on regional collagen biosynthesis and concentration in the hearts of male beagle dogs were studied by measuring prolyl 4-hydroxylase (PH) activity and hydroxyproline (HYP) concentration. The PH (P less than 0.05) and HYP (P less than 0.05) were both greater in the subendocardinal layer than in the subepicardium (EPI) of the left ventricular wall in controls, whereas opposite gradients (P less than 0.05) were observed in the right ventricle. Endurance exercise caused an increase of PH activity in EPI of the left ventricular wall (P less than 0.01). The HYP concentration increased in both layers of the right ventricle in the exercise plus steroid group (P less than 0.05). The results suggest that transmural differences exist in the rate of collagen synthesis and concentration in canine cardiac ventricles and that endurance exercise may accelerate collagen synthesis in EPI of the left ventricle and the combination of exercise and anabolic steroid causes an increase in collagen concentration in the right ventricular wall.

Alkaline Phosphatase↗

PubMed1991

Night-rest urinary catecholamine excretion in relation to aspects of free time, work and background data in a teacher group.

Free time, work and background data were related to night-rest catecholamine excretion rates in a teacher group (n = 137) during an autumn term. The explained interindividual variance increased slightly towards the end of the term. Adrenaline excretion was predicted better than noradrenaline, notedly by coffee consumption, amount of physical activity, and subjective stress feelings which explained 16% of the variance in adrenaline excretion during night rest. However, the results indicated that the differences in catecholamine excretion during night rest remained mostly unpredictable.

Adult↗

PubMed1991

Muscle enzyme adaptations to added load during training and nontraining hours in rats.

The effects of added load (20% of body mass) on the selected enzyme activities of red and white quadriceps femoris (QF), soleus, and gastrocnemius muscles of rats were studied. The rats were divided into sedentary control (SC), sedentary control with added load (SC+AL), endurance training (ET), and endurance training with added load (ET+AL) groups (n = 10 rats/group). After 6 wk, the SC+AL group had 57% higher (P less than 0.001) beta-glucuronidase (beta-GU) activity and 24% lower (P less than 0.05) citrate synthase activity in white QF than SC. Citrate synthase activity was also decreased in red QF (P less than 0.05) after the added load was used during nontraining hours. The training with added load induced similar but more pronounced changes than normal endurance training, especially in white QF. The ET+AL group demonstrated higher citrate synthase activity in white QF (P less than 0.001) and gastrocnemius (P less than 0.01) and higher malate dehydrogenase activity (P less than 0.05) and beta-GU activity (P less than 0.001) in white QF than the ET group. ET+AL rats also had higher phosphofructokinase (P less than 0.01) and lower creatine kinase (P less than 0.001) activity in white QF than ET rats. In conclusion, the added load without training had minor adaptive influences on muscles. The added load during training hours seemed to be an effective means of influencing the activation and adaptation in muscles that contain fast glycolytic fibers.

Adaptation, Physiological↗

PubMed1988

Protein synthesis and cyclic GMP content in rat cardiac muscle after swimming exercise.

Rats were exercised for 6 h by swimming. Phenylalanine incorporation into myocardial proteins was increased when 2 h had elapsed after the termination of exercise. Cyclic GMP concentration did not change during the experiment, which indicates that cyclic GMP does not act directly as a trigger of myocardial protein synthesis in volume overload.

Animals↗

PubMed1988

Food deprivation decreases the exertion-induced acid hydrolase response in mouse skeletal muscle.

Strenuous prolonged running causes muscle fibre necrosis in skeletal muscles. The muscle injury is associated with inflammation and a strong increase in the total activities of certain acid hydrolases a few days after exertion. The activity changes of acid hydrolases quantitatively well reflect the severity of histopathological changes during the myopathy (for review see Salminen, Acta Physiol Scand [Suppl 539] 1985). In this study male NMRI-mice were exposed to a protocol of fasting and refeeding together with or without a 6 h run on a treadmill at 13.5 m.min-1. The animals were killed 4 days after the exercise and samples from the red part of quadriceps femoris were analyzed for arylsulfatase (ASase) and beta-glucuronidase (GUase) activities. Starvation protocols did not affect ASase or GUase. Running caused a 3.2-fold increase in ASase and a 5.1-fold increase in GUase. If mice were exercised in the fasted condition a normal exercise response occurred in both activities, but when mice were exercised 2 days after the finish of fasting the exercise response was greatly diminished. Thus food deprivation followed by 2 days refeeding induces a protection against exercise myopathy in mice. The protection greatly resembles that induced by regular endurance training preceding strenuous prolonged exertion.

Animals↗

PubMed1988

Transmural distribution of biochemical markers of total protein and collagen synthesis, myocardial contraction speed and capillary density in the rat left ventricle in angiotensin II-induced hypertension.

The effect of angiotensin II-induced hypertension on selected biochemical parameters was studied in Sprague-Dawley rats. Angiotensin II infusion at rates of 41.7 micrograms h-1 kg-1 and 12.5 micrograms h-1 kg-1 for 2, 5, 10 and 15 days elevated the systolic blood pressure from 143 +/- 7 mmHg to 215-230 mmHg (P less than 0.001) and 185-195 mmHg (P less than 0.001), respectively. The left ventricular weight/body weight ratio increased 10-14% (P less than 0.05) and 23-32% (P less than 0.001) after 2-15 days in rats treated at the lower and higher infusion rates, respectively. Prolyl 4-hydroxylase (PH) activity, a marker of collagen synthesis, was evenly distributed in the left ventricle. PH activity increased by about 100% in both subendocardial and subepicardial layers of the left ventricular wall after angiotensin II infusion for 10 days at 41.7 micrograms h-1 kg-1, but remained unaltered at 12.5 micrograms h-1 kg-1. No change was observed in hydroxyproline concentration. Myosin isoenzymes (V1-V3), which reflect myocardial contractility, were unevenly distributed in the left ventricular wall: the proportion of the fast-turnover isoenzyme (V1) was smaller in the subendocardial layer than in the subepicardial layer. The proportion of V1 decreased after treatment in both layers. Alkaline phosphatase activity, a marker of capillary density, was evenly distributed transmurally in the left ventricular wall. Angiotensin II caused a slight decrease in this activity in both myocardial layers. The results suggest that the elevation of blood pressure leads to transmurally evenly distributed changes in biochemical parameters reflecting collagen synthesis, capillary density and contractile properties of the myocardium.

Alkaline Phosphatase↗

PubMed1988

Effects of denervation and immobilization on collagen synthesis in rat skeletal muscle and tendon.

The activities of prolyl 4-hydroxylase (PH) and galactosylhydroxylysyl glucosyltransferase (GGT), both enzymes of collagen biosynthesis, and the concentration of hydroxyproline (HYP) were measured in the gastrocnemius, soleus, and tibialis anterior muscles of rats after sciatic nerve neurectomy combined with cast immobilization of the denervated limb for 1 and 3 wk. PH and GGT were also observed in Achilles and tibialis anterior tendons after cast immobilization without neurectomy. After neurectomy the specific PH activity in the denervated gastrocnemius muscle increased by 215% (P less than 0.001). The specific GGT activity increased by 92-110% (P less than 0.01) in the denervated gastrocnemius, soleus, and tibialis anterior muscles. Elevation of the muscular HYP concentration by 118-170% (P less than 0.001) in the denervated muscles was observed. The PH, GGT, and HYP responses of the denervated muscles immobilized at a lengthened or shortened position during denervation atrophy did not generally differ significantly from those of the unfixed denervated ones. The specific PH and GGT activities of the disused tendons decreased by 62 (P less than 0.01) and 25% (P less than 0.001), respectively, in tendons immobilized in a chronically shortened position. The results suggest that denervation atrophy of skeletal muscle is associated with both an increased level of muscular collagen biosynthesis and with an increased muscular collagen concentration. The PH and GGT responses of the cast-immobilized tendons suggest adaptive changes in collagen biosynthesis of the disused tendon.

Adaptation, Physiological↗

PubMed1988

Collagen synthesis and proteolytic activities in rat skeletal muscles: effect of cast-immobilization in the lengthened and shortened positions.

The activities of prolyl 4-hydroxylase (PH) and galactosylhydroxylysyl glucosyltransferase (GGT), both enzymes of collagen biosynthesis, were measured in the gastrocnemius, soleus, and tibialis anterior muscles of rats after bilateral cast-immobilization of the muscles in lengthened and shortened positions for one and three weeks. The activities of muscular proteolytic and hydrolytic enzymes cathepsin D (CD), beta-glucuronidase (beta-GU), alkaline protease (AP), and the rate of acid autolysis (AA) were also studied. The biochemical results were compared to the morphologic changes by light microscopy. Compared to the results for a control group, there was a decrease of 37% and 53% in the specific PH activity of shortened gastrocnemius and soleus, respectively, after three weeks of immobilization. The corresponding decrease in GGT of the shortened gastrocnemius was 47%. At the same time, PH and GGT in the lengthened plantarflexors were at the control level. The proteolytic activities of the shortened plantarflexors were generally higher (CD by approximately 30%, beta-GU of gastrocnemius by 81%, AP of soleus by 63%, AA of gastrocnemius by 34%, and AA of soleus by 56%) than those of the lengthened ones. Light microscopy of the shortened muscles showed numerous atrophic fibers, but no pronounced inflammatory response in the disused muscle tissue. The results suggest that increased proteolysis and wasting of muscle tissue during cast-immobilization is associated with adaptive responses in the metabolism of the muscular collagen network.

Animals↗

PubMed1987

Effect of immobilization on collagen synthesis in rat skeletal muscles.

The activities of prolyl 4-hydroxylase (PH) and galactosylhydroxylysyl glucosyltransferase (GGT), both enzymes of collagen biosynthesis, and the concentration of hydroxyproline (Hyp) were measured in the soleus, gastrocnemius, and tibialis anterior muscles of rats after cast immobilization in the middle position for 1 or 3 wk. The specific activity of PH decreased by 54 and 70-75% (P less than 0.001) in the soleus muscle after 1 and 3 wk, respectively, the corresponding decreases in GGT activity were 43 and 47% (P less than 0.001). A less pronounced decrease in the activities of these enzymes was observed in gastrocnemius and tibialis anterior muscles. The Hyp concentration in the soleus increased during the first week of immobilization but began to decrease thereafter, and the total muscular Hyp content was reduced after immobilization for 3 wk. The results suggest a marked inhibition of muscular collagen synthesis during immobilization. Electrical stimulation of the sciatic nerve partially prevented this disuse atrophy and the decreases in PH, GGT, and Hyp in the tibialis anterior muscle but not in the gastrocnemius or soleus muscles.

Animals↗

PubMed1986

Chronic hydrogen peroxide intake and peroxide metabolizing enzyme activities in some tissues of mice and rats.

Chronic daily intake of 0.5% H2O2 in drinking water decreased Se-dependent glutathione peroxidase (Se-GSHPx) activity in rat skeletal muscle, kidney and liver. Non-Se GSHPx activity decreased in kidney. Deprivation of drinking water decreased Se-GSHPx activity in kidney and non-Se GSHPx activity in kidney and liver. H2O2 intake decreased activity of catalase in rat skeletal muscle. H2O2 intake or water deprivation caused no changes in these enzyme activities in mice.

Animals↗

PubMed1986

Collagen metabolism of mouse skeletal muscle during the repair of exercise injuries.

The activities of prolyl 4-hydroxylase and beta-glucuronidase, the concentration of hydroxyproline as well as reticulin and collagen type III, IV and V stainings were followed in skeletal muscle during a 20-day period after a 9-h treadmill running in untrained and trained male mice, aged 4-6 months. The prolonged 9-h running of untrained mice temporarily increased prolyl 4-hydroxylase activity 2, 5 and 10 days after exercise, more prominently in the red than in the white part of quadriceps femoris-muscle, and in analogical manner as beta-glucuronidase activity in tibialis anterior-muscle. Twenty days after exercise these enzymatic activities were back to the control level. The hydroxyproline content of red muscle was increased for 10 and that of white muscle for 20 days after the exertion. Training for 45 days did not affect hydroxyproline content and prolyl 4-hydroxylase activity was at the control level after the training. A 9-h exercise increased prolyl 4-hydroxylase activity much less in trained muscle than in the untrained muscle and did not affect muscle collagen content. Histological observations showed fiber necrosis 2 days and signs of fiber regeneration 5 days after the exertion in untrained mice. Twenty days afterwards the regeneration was nearly completed. Reticulin staining was increased in injured muscle areas 10-20 days after the exertion. In immunohistochemical staining, antibodies to all studied collagen types (type III, IV and V) showed increased staining 5-20 days after the exertion in the areas of muscle injuries and regeneration.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1986

Activities of some antioxidative and hexose monophosphate shunt enzymes of skeletal muscle in neuromuscular diseases.

The activities of some antioxidative and hexose monophosphate shunt enzymes, as well as of 2 hydrolases were studied in skeletal muscle biopsy specimens taken from 39 patients with neuromuscular diseases and from 15 controls. The activity of Se-dependent glutathione peroxidase was higher in patients with congenital myotonia, whereas in the other diagnostic groups this enzyme activity was the same as in the controls. The Se-independent and total glutathione peroxidase activity of patients in the various diagnostic groups did not differ from the controls. Moreover, no difference were observed in catalase activity between the patient groups and the controls. The activities of the rate limiting enzymes of hexose monophosphate shunt, glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase of muscle biopsy samples of various patient groups did not show any significant difference from controls. The activity of a lysosomal hydrolase, beta-N-acetylglucosaminidase, was increased in patients with polyneuropathy and the activity of a nonlysosomal protease, alkaline protease, was high in patients with Charcot-Marie-Tooth disease. The activities of Se-dependent glutathione peroxidase, 6-phosphogluconate dehydrogenase and of both hydrolases showed a significant correlation to the magnitude of muscle atrophy.

Acetylglucosaminidase↗

PubMed1985

Redistribution of glucose uptake by chronic exercise, measured in isolated perfused rat hearts.

The effects of 8-9 weeks of running and swimming training on the transmural distribution of cardiac glucose uptake and protein synthesis in isolated perfused heart were studied in male rats. The left ventricular glucose uptake in hearts from sedentary rats was 2.5 +/- 0.3 mumoles/min per g protein (mean +/- S.D.), and about 30% higher in the subendocardial layer than in the subepicardial layer (P less than 0.01). After the running and swimming programs the total left ventricular glucose uptake was at the level of sedentary rats, but the gradient was absent. The rate of protein synthesis was evenly distributed through the left ventricular wall and similar in all experimental groups. The altered transmural distribution of glucose uptake after exercise probably reflects differences in the adaptive response of various myocardial muscle layers to a long-term intermittent increase in the cardiac work load.

Animals↗

PubMed1985

Latency differences of lysosomal enzymes in cardiac and skeletal muscles of male and female mice.

The purpose of this study was to compare the latencies of lysosomal enzymes (beta-glucuronidase, beta-N-acetylglucosaminidase, arylsulphatase and acid ribonuclease) in heart and in red and white skeletal muscle of male and female mice (Mus musculus). The unsedimentable, free activities together with releasable (Triton X-100, hypotonic shock and freeze-thawing treatments) and unreleasable, bound activities were assayed. The distribution of acid hydrolases to different fractions was strikingly heterogeneous. The most distinct differences occurred between the distributions of beta-glucuronidase and beta-N-acetylglucosaminidase. The differences between muscle types occurred in the activity levels of lysosomal enzymes, rather than in the fractional distributions. Sex-related differences were small and occurred mainly in the activity levels of heart muscle (higher in female mice). The results suggest that the heterogeneous distribution of lysosomal enzymes originates in the compartmental differences of lysosomal enzymes in muscle cells, rather than the differences in cell populations of different muscle types.

Acetylglucosaminidase↗

PubMed1984

Endurance training and antioxidants of lung.

Mice and rats were adjusted to daily treadmill training programs, which were heavy enough to increase the oxidative capacity of skeletal muscles. Endurance training did not affect the activities of catalase and glutathione peroxidase and the concentration of vitamin E in the lungs of mice and rats. Thus increased ventilation and oxygen utilization induced by exercise training do not modify lung antioxidants, in contrast to hyperoxia and hypoxia.

Animals↗