0000000000015297
AUTHOR
Timo E.s. Takala
showing 14 related works from this author
Effects of power training on muscle structure and neuromuscular performance
2005
The present study examines changes in muscle structure and neuromuscular performance induced by 15 weeks of power training with explosive muscle actions. Twenty-three subjects, including 10 controls, volunteered for the study. Muscle biopsies were obtained from the gastrocnemius muscle before and after the training period, while maximal voluntary isometric contractions (MVC) and drop jump tests were performed once every fifth week. No statistically significant improvements in MVC of the knee extensor (KE) and plantarflexor muscles were observed during the training period. However, the maximal rate of force development (RFD) of KE increased from 18,836+/-4282 to 25,443+/-8897 N (P0.05) durin…
mRNA levels for α-subunit of prolyl 4-hydroxylase and fibrillar collagens in immobilized rat skeletal muscle
1999
There is evidence that immobilization causes a decrease in total collagen synthesis in skeletal muscle within a few days. In this study, early immobilization effects on the expression of prolyl 4-hydroxylase (PH) and the main fibrillar collagens at mRNA and protein levels were investigated in rat skeletal muscle. The right hindlimb was immobilized in full plantar flexion for 1, 3, and 7 days. Steady-state mRNAs for α- and β-subunits of PH and type I and III procollagen, PH activity, and collagen content were measured in gastrocnemius and plantaris muscles. Type I and III procollagen mRNAs were also measured in soleus and tibialis anterior muscles. The mRNA level for the PH α-subunit decreas…
Effects of Training on the Exercise-Induced Changes in Serum Amino Acids and Hormones
2002
The purpose of this study was to examine power-type athletes to determine changes in amino acid and hormone concentrations in circulating blood following 2 different high-intensity exercise sessions before and after the 5-week training period. Eleven competitive male sprinters and jumpers performed 2 different running exercise sessions: a short run session (SRS) of 3 x 4 x 60 m (intensity of 91-95%) with recoveries of 120 and 360 seconds, and a long run session (LRS) with 20-second intervals (intensity of 56-100%) with recoveries of 100 seconds to exhaustion. The concentrations of serum amino acids, hormones, and lactate were determined from the blood samples drawn after an overnight fast a…
Pre- and Post-translational Regulation of Lysyl Oxidase by Transforming Growth Factor-β1 in Osteoblastic MC3T3-E1 Cells
1995
The final enzymatic step required for collagen cross-linking is the extracellular oxidative deamination of peptidyl-lysine and -hydroxylysine residues by lysyl oxidase. A cross-linked collagenous extracellular matrix is required for bone formation. The goals of this study were to compare the transforming growth factor (TGF)-beta 1 regulation of lysyl oxidase enzyme activity and steady state mRNA levels to changes in COL1A1 mRNA levels in MC3T3-E1 osteoblastic cells. TGF-beta 1 increased steady state lysyl oxidase and COL1A1 mRNA levels in a dose- and time-dependent manner. The increase in lysyl oxidase mRNA levels was transient, peaking at 12 h and 8.8 times controls in cells treated with 4…
Type IV collagen and its degradation in paralyzed human muscle: Effect of functional electrical stimulation
2000
The purpose of this study was to evaluate the effects of spinal cord injury (SCI) and functional electrical stimulation (FES) of paralyzed muscles on type IV collagen content and proteins involving its degradation, which is initiated by matrix metalloproteinase (MMP)-2 and -9 and regulated by their tissue inhibitors (TIMPs)-2 and -1. Ten SCI subjects participated in an 18-month program of functional electrical stimulation (FES) of their leg muscles. Needle biopsies were taken from the vastus lateralis muscle before and at various times during the training period, and from able-bodied controls. Type IV collagen concentration was unaltered. ProMMP-2 level of SCI subjects before the training p…
Serum concentrations of collagen degrading enzymes and their inhibitors after downhill running
2001
In the present study the release of proteins degrading extracellular matrix compounds to circulation was measured after damaging exercise in humans. Muscle damage was induced by downhill running; furthermore, the exercise was performed at both cold temperature (5 degrees C) and room temperature (22 degrees C) to study also the possible effect of environmental temperature on serum concentrations of matrix metalloproteinases MMP-2 and MMP-9, tissue inhibitors of metalloproteinases TIMP-1 and TIMP-2, and MMP-2/TIMP-2 complex, and muscle damage monitored by serum creatine kinase measurements. Results were compared with those obtained from patients having rhabdomyolysis, myositis and Becker musc…
Reduced stretch-reflex sensitivity after exhausting stretch-shortening cycle exercise.
1996
The stretch-shortening cycle (SSC) is an effective and natural form of muscle function but, when repeated with sufficient intensity or duration, it may lead to muscle damage and functional defects. A reduced tolerance to impact has been reported, which may be partly attributed to a reduced stretch-reflex potentiation. The aim of the present study was to examine the influence of SSC-induced metabolic fatigue and muscle damage on the efficacy of stretch reflexes, as judged by the electromyograph (EMG) response of two shank muscles (lateral gastrocnemius LG, soleus SOL) to controlled ramp stretches. These EMG responses were recorded before and immediately after exhausting SSC-type leg exercise…
Protein targeting to the plasma membrane of adult skeletal muscle fiber: an organized mosaic of functional domains.
2001
The plasma membrane of differentiated skeletal muscle fibers comprises the sarcolemma, the transverse (T) tubule network, and the neuromuscular and muscle-tendon junctions. We analyzed the organization of these domains in relation to defined surface markers, beta-dystroglycan, dystrophin, and caveolin-3. These markers were shown to exhibit highly organized arrays along the length of the fiber. Caveolin-3 and beta-dystroglycan/dystrophin showed distinct, but to some extent overlapping, labeling patterns and both markers left transverse tubule openings clear. This labeling pattern revealed microdomains over the entire plasma membrane with the exception of the neuromuscular and muscle-tendon j…
Effects of bovine colostrum supplementation on serum IGF-I, IgG, hormone, and saliva IgA during training.
1997
Mero, Antti, Heidi Miikkulainen, Jarmo Riski, Raimo Pakkanen, Jouni Aalto, and Timo Takala. Effects of bovine colostrum supplementation on serum IGF-I, IgG, hormone, and saliva IgA during training. J. Appl. Physiol.83(4): 1144–1151, 1997.—The purpose of this study was to examine the effects of bovine colostrum supplementation (Bioenervi) on serum insulin-like growth factor I (IGF-I), immunoglobulin G, hormone, and amino acid and saliva immunoglobulin A concentrations during a strength and speed training period. Nine male sprinters and jumpers underwent three randomized experimental training treatments of 8 days separated by 13 days. The only difference in the treatments was the drink of 125…
Elevated Protein Content and Prolyl 4-Hydroxylase Activity in Severely Degenerated Human Annulus Fibrosus
2000
Alterations involved with the intervertebral disc degeneration are partly well described, however, it is not so well known how collagen network is affected by the disease. We analyzed the rate of collagen biosynthesis (estimated by the enzymic activities of prolyl 4-hydroxylase and galactosylhydroxylysyl glucosyltransferase) and the level of hydroxylysylpyridinoline and lysylpyridinoline crosslinks both in normal (n=7) and degenerated (n=7) human annulus fibrosus. The activity of prolyl 4-hydroxylase was significantly increased in degenerated tissue. However, no significant changes in the collagen content or in the amount of hydroxylysylpyridinoline and lysylpyridinoline collagen crosslinks…
Effects of power training on mechanical efficiency in jumping.
2003
The present study investigates the effects of power training on mechanical efficiency (ME) in jumping. Twenty-three subjects, including ten controls, volunteered for the study. The experimental group trained twice a week for 15 weeks performing various jumping exercises such as drop jumps, hurdle jumps, hopping and bouncing. In the maximal jumping test, the take-off velocity increased from 2.56 (0.24) m.s(-1) to 2.77 (0.18) m.s(-1) ( P<0.05). In the submaximal jumping of 50% of the maximum, energy expenditure decreased from 660 (110) to 502 (68) J.kg(-1).min(-1) ( P<0.001) while, simultaneously, ME increased from 37.2 (8.4)% to 47.4 (8.2)% ( P<0.001). Some muscle enzyme activities of the ga…
The disruption of myofibre structures in rat skeletal muscle after forced lengthening contractions.
1998
Specific antibodies against structural proteins (actin, desmin, dystrophin, fibronectin) of muscle fibres were used to study the effect of forced lengthening contractions on muscle microarchitecture. Tibialis anterior (TA) muscle of male Wistar rats were subjected to 240 forced lengthening contractions. At consecutive time points (0, and 6 h, 2, 4, and 7 days) after stimulation, the TA muscle was excised for biochemical and histological assays. Beta-Glucuronidase activity, a quantitative indicator of muscle damage, showed increased values 2-7 days after the lengthening, peaking on day 4 (11.7-fold increase). A typical course of histopathological changes (myofibre swelling, necrosis and rege…
Warm underwater water-jet massage improves recovery from intense physical exercise
1995
The effects of warm underwater water-jet massage on neuromuscular functioning, selected biochemical parameters (serum creatine kinase, lactic dehydrogenase, serum carbonic anhydrase, myoglobin, urine urea and creatinine) and muscle soreness were studied among 14 junior track and field athletes. Each subject spent, in a randomized order, two identical training weeks engaged in five strength/power training sessions lasting 3 days. The training weeks differed from each other only in respect of underwater water-jet massage treatments. These were used three times (20 min each) during the treatment week and not used during the control week. During the treatment week continuous jumping power decre…
Biochemical composition of muscle extracellular matrix: the effect of loading
2000
Collagen plays an important role in skeletal muscle both during muscle differentiation and normal muscle growth, and also serves a role as a supportive structure. It is the most abundant protein of the extracellular matrix and of the 19 distinct collagen types, types I, III, IV and V are the dominating ones in skeletal muscle. Both collagen synthesis as well as degradation is influenced by either physical loading or immobilization in skeletal muscle, and recent methods have allowed for greater understanding of the posttranslational processing of collagen.