To assess the changes in glycolysis of skeletal muscles within metabolic stress and to test whether metabolic stress-induced oxidative stress and malnutrition were associated with these changes, slow- (soleus) and fast-twitch extensor digitorum longus (EDL) muscles were studied in zymosan-induced critically ill, pair-fed and control rats for 7 days. Thiobarbituric acid reactive species (TBARS) concentrations were increased in both stressed and pair-fed rats. In slow-twitch muscle, the fructose-1,6-bisphosphate (F-1,6-P2)/fructose-6-phosphate (F-6-P) ratio was decreased in stressed rats and was not altered with increased food intake. F-1,6-P2/F-6-P ratio in soleus was correlated with both TBARS and muscle dry weight. In EDL, the F-1,6-P2/F-6-P was unaffected and neither oxidative stress nor muscle weight correlated with the ratio. In conclusion, metabolic stress-induced oxidative stress and malnutrition influenced glycolytic slowdown only in slow-twitch muscle.

Cyclooxygenase (COX) is the enzyme that catalyzes the rate-limiting step in prostaglandin (PG) synthesis. In skeletal muscle, PGF2a, has been shown to regulate protein synthesis, and ibuprofen and acetaminophen have been shown to block the normal increase in PGF2a and muscle protein synthesis following resistance exercise in humans. The purpose of this investigation was to determine the expression of the COX-1 (COX-1 variants: COX-1 v1, -1v2, -1 b,, -1 b2, and -1b3) and COX-2 isoforms following resistance exercise to help elucidate the isoform or variant through which PGF2a, ibuprofen, and acetaminophen regulate muscle protein synthesis. Human skeletal muscle biopsy samples were taken from 16 individuals (8M, 8F) before, 4 h, and 24 h following a single bout of resistance exercise and analyzed using real-time RT-PCR. COX-Iv1 and COX-1v2 were the most abundant COX mRNA before exercise and remained unchanged (P>0.05) following exercise (i.e., constitutively expressed). Relatively few individuals expressed the intron 1-retaining COX-1 b variants (COX-1 b,, - 1b2, and -1 b3) at any time point, and when expressed these variants were in very low abundance. COX-2 was not expressed in any subject before exercise, but increased significantly (P<0.05) at 4 and 24 h following exercise. These results suggest that the intron 1-retaining COX-1 b,, -1 b2, and -lb3 variants are likely not the COX through which PGF2a is produced to stimulate skeletal muscle protein synthesis. PGF2a, stimulation, as well as ibuprofen and acetaminophen inhibition of skeletal muscle protein synthesis likely work through COX-2, or one of the constitutively expressed COX-1 variants (COX-lv1 or -1v2). / School of Physical Education, Sport, and Exercise Science

The conductor of a large instrumental ensemble is constantly confronted with the task of detecting and correcting rhythm and pitch performance errors in daily rehearsals. The purpose of this investigation was to design a computer-assisted instruction program for error detection skills development and then evaluate this program's effectiveness in training beginning conductors to identify rhythm and pitch errors within 2-, 3-, 4-, and 5-voice synthesized music excerpts from the existing band literature. The transfer of error detection skills from synthesized to acoustic sounds also was explored indirectly by virtue of utilizing taped excerpts from wind band performances to assess error detection skills.Subjects (N=24) in this study were drawn from the pool of undergraduate instrumental music education majors at Ball State University and were randomly assigned to control treatment groups prior to the administration of the Acoustic Error Detection Skills Inventory. Following this pretest, the treatment group used the Computer Error Detection Skills Program for approximately eight hours during an eight week treatment period. At the end of the treatment period, and control and treatment groups were administered the Acoustic Error Detection Skills Inventory posttest.The data were analyzed using a series of one-way, repeated measures analyses of variance (ANOVA) to assess pretest to posttest changes in subjects' scores on the Acoustic Error Detection Skills Inventory. Composite scores (reflecting general skill in error detection) improved significantly for the treatment group (p = .007), while the pretest to posttest gain for the control group was not statistically significant (p = .232). These results suggest that the Computer Error Detection Skills Program was effective in enhancing subjects' rhythm and pitch error detection skills and the viability of using synthesized sound sources for training was confirmed.The following recommendations were made: (1) Jazz directors need to do more listening to jazz music, (2) band directors who direct jazz programs should join IAJE, (3) jazz ensembles shouldtheir own improvisational skills, and rehearse in the fall, (4) jazz ensemble directors should develop (5) jazz ensemble directors should have their students sing their parts during rehearsals for increased learning efficiency and retention. / Human Performance Laboratory

The purpose of this investigation was to examine the effects of exercise and diet on muscle triglyceride. Seven endurance-trained men completed a 120min cycling bout at 65% of V O2max in an attempt to lower muscle glycogen and triglyceride. Each subject then ingested an isocaloric, high-carbohydrate (HI-CHO; 83% of kcal) or high-fat (HI-FAT; 68% of kcal) diet for the ensuing 24 h. A 1600 kJ cycling time trial was completed following this 24-h dietary period. Muscle glycogen concentration before (571±38 vs. 599±41 mmol•kg dw-1) and after (241±36 vs. 285±41 mmol•kg dw-1) the 120-min cycling bout was not different (P>0.05) between the HI-CHO and HI-FAT trials, respectively. Muscle triglyceride concentration before (33.0±2.3 vs. 37.0±2.1 mmol•kg dw-1) and after (30.9±2.4 vs. 32.8±1.6 mmol•kg dw-1) the 120-min cycling bout was also not different between the HI-CHO and HI-FAT trials, respectively. In addition, muscle triglyceride did not decrease significantly during the cycling bout for the HI-CHO (2.1±2.1 mmol•kg dw-1) or HI-FAT (4.2±1.8 mmol•kg dw-1) trial. Over the 24-h dietary period, a significantly greater amount of glycogen was resynthesized during the HI-CHO (308±41 mmol•kg dw-1) versus the HI-FAT trial (42±23 mmol•kg dw-1). Muscle triglyceride concentration increased 11.9±1.6 mmol•kg dw-1 (P<0.05) and decreased 3.4±1.8 mmol•kg dw-1 (P>0.05) during the 24-h dietary period for the HI-FAT and HI-CHO trials, respectively. Cycling performance time was significantly greater during the HI-FAT (139.3±7.1 min) compared to the HICHO (117.1±3.2) trial. The average V02 (3.40±0.12 vs. 2.96±0.17 L•min-1) and RER (0.89±0.01 vs. 0.82±0.01) during the time trial were higher for the HI-CHO than the HI-FAT trial, respectively. These data demonstrate that a small, insignificant amount of muscle triglyceride is utilized during prolonged, moderate-intensity cycling. Furthermore, 24 h of a high-fat diet increased muscle triglyceride concentration and reduced endurance performance. / Human Performance Laboratory

As a part of a project designed to mimic a Space Shuttle flight (LMS), eight healthy males completed 17 d of -6° head down tilt bedrest to assess the in vivo torque velocity relationship of the calf muscle group and the cardiorespiratory responses to supine cycling exercise. The subjects age, height, and weight were 42.7 ±8.1 y, 182.3 ±6.5 cm, and 82.2 ±12.1 kg, respectively. Testing was completed prior to bedrest (CON), on bedrest days 2 & 3 (BR 1), 8 & 9 (BR2), and 13 & 14 (BR3), as well as recovery days 3 & 4 (R1), and 7 & 8 (R2). Maximal plantar flexion force production at seven angular velocities (0, 30, 60, 120, 180, 240, 300'- s-1) was unchanged (P>0.05) during bedrest and recovery. Muscle biopsy specimens obtained from the soleus before and on day 17 of bedrest showed no change (P>0.05) in muscle fiber composition, muscle fiber area, capillary to fiber ratio, or capillary density. Citrate synthase activity decreased 21% (P<0.05) from 122.1 ±7.8 to '97.1 ±5.1 µmol -min-1 • g dry wt-1, while phosphorylase activity was unchanged (P>0.05). VO2max (L • min-1) was decreased (P<0.05) from CON (3.24 ±0.20) during BR1 (2.99 ±0.17; -7.3%), BR2 (3.00 ±0.17; -7.1%), BR3 (2.92 ±0.20; -9.0%), and R1 (3.02 ±0.20; -6.6%), but was not different (P>0.05) than CON by R2 (3.13 ±0.19; -3.3%). Maximal heart rate and ventilation did not change (P>0.05) from CON during bedrest or recovery. Initial changes in VO2max (BR1) were significantly correlated with fluid balance during bedrest day 1 (r=0.91, P<0.05). These data suggest that the testing protocols in this investigation may be sufficient to attenuate functionally significant changes in muscle morphology and strength during 17 d of simulated microgravity. The results also suggest that the time course for changes in VO2max are not linear and are related to the initial changes in body fluid volumes. / Human Performance Laboratory

Two experiments were done to study the effects of L-carnitine supplementation (CNsup) during exercise. EXP 1, examined the effect of CNsup on lipid oxidation and muscle glycogen utilization during submaximal EX. Triglycerides were elevated by a fat feeding (90g fat), 3 h later subjects cycled for 60 min at 70% VO2max (CON). Muscle biopsies were obtained preEX, after 30 and 60 min of EX. Blood samples were taken preEX and every 15 min of EX. Subjects randomly completed two additional trials following 7 and 14 days of CNsup (6 g/day). During one of the trials, subjects received 2000 units of heparin 15 min prior to EX to elevate FFA (CNhep). There were no differences in V02, RER, HR, g of CHO and fat oxidized among the three trials. Serum total acid soluble (TASC) and free carnitine (FC) increased with CNsup (CON, 71.3 ± 2.9; CN, 92.8 ± 5.4; CNhep, 109.8 ± 3.5 mol·g'). Muscle carnitine concentration at rest was unaffected by CNsup. During EX, TASC did not change, FC decreased (p<0.05) and SCAC increased (p<0.05). With CNsup the decrease in FC was less (~50%) (p<0.05) and the increase in SCAC was greater (~200-300%) (p<0.05) compared to CON (free 65%; SCAC 150%). Pre and postEX muscle glycogens were not different. EXP 2, examined the effects of CNsup on blood lactate accumulation during maximal EX. Subjects cycled for 4 min at ~100% VO2max (CON). Exercise was repeated following 6 and 13 days of CNsup (6 g/day). Serum TASC and FC were elevated due to CNsup. Blood Lactate was measured prior to and 0, 3, 5, and 7 min postEX. CNsup resulted in less (p<0.05) lactate accumulation compared to CON. There were no differences between DAY-6 and DAY-13. / Human Performance Laboratory

Intramuscular connective tissue is critical in maintaining muscle structure and the transfer of force from contractile elements to the bone. We examined intramuscular connective tissue characteristics in young and old men and women, as well as men and women subjected to simulated microgravity. We hypothesized that intramuscular collagen content, collagen cross-linking and formation of advanced glycation endproducts of old individuals would be greater than young, and that intramuscular collagen content would be elevated following prolonged periods of unloading spanning 35, 60 and 90 days. Vastus lateralis muscle biopsies revealed that intramuscular collagen (Young: 9.6±1.1, Old: 10.2±1.2 ug•mg muscle wet wf-') and collagen cross-links (hydroxylysylpyridinoline, HP) (Young: 395±65, Old: 351±45 mmol HP•mol collagen-1) were unchanged (p>0.05) with aging. The advanced glycation endproduct, pentosidine, was increased (p<0.05) by 203% (Young: 5.2±1.3, Old: 15.9±4.5 mmol pentosidine•mol collagen"') with aging. With unloading, collagen content of the vastus lateralis was unchanged (p>0.05) following all time periods but was found to be elevated (p<0.05) in the soleus following 90 days of unloading. Furthermore, baseline collagen content was found to greater (p<0.05) in the soleus compared to the vastus lateralis. These results suggest the age related decline in whole muscle function is not related to increases in intramuscular collagen content or cross-linking but may be related to the accumulation of advanced glycation endproducts. Muscle function following unloading does not appear to be impacted by collagen content in the vastus lateralis but may play a role in the soleus. / School of Physical Education, Sport, and Exercise Science

No description available.

No description available.

Chicken breast muscles (Pectoralis major and Pectoralis minor) were subjected to low doses of gamma radiation (≤ 0.50 Mrad) within 20-30 min. post-slaughter. pH decline extractability of different muscle protein fractions, shear force, isometric tension pattern and sarcomere length were evaluated at definite intervals of post mortem storage period. pH measurements from 1/2 hour to 72 hours post mortem revealed a stimulation of pH decline immediately after irradiation in 0.25 and 0.50 Mrad treated muscle samples but this effect was subsequently found to be nullified and an ultimate pH of about 5.55 was reached between 6-12 hours in all the samples. Extractability of total soluble and total myofibrillar proteins of muscle increased with post mortem time. A clear effect of irradiation treatments of increased extractability of actomyosin especially in the post rigor period was observed and this effect was more noticeable in 0.50 Mrad than in 0.25 Mrad samples. Comparatively less extractable actomyosin was found during the post rigor period of storage particularly in control samples. There was no significant effect of radiation doses, time of storage or their interactions on the solubility of sarcoplasmic proteins or of four minor fractions of protein and non-protein substances. The level of extractable actomyosin was found to be significantly related (r² = 0.12; df=46) with the corresponding shear press measurements. Irradiated samples had significantly higher mean shear values and more extractable actomyosin than the control samples especially during the post rigor period. Irradiation (0.125 and 0. 250 Mrad) was found to stimulate post mortem development of isometric tension in muscle strips. In irradiated samples maximum tension was developed about 2 hours ahead of the corresponding controls. A 50% decline of isometric tension was achieved in 6-8 hours post mortem, while a 50% decline of tension in control samples required more than 12 hours. The general relationship of isometric tension pattern and extractability of actomyosin was found to be low. Sarcomere length was related (r² = .38; df = 6) with shear values such that a small change in sarcomere length was found to result in a relatively large change in shear press values. Irradiated samples with relatively shorter sarcomeres in the post rigor period were found to have significantly lower mean shear values when compared with their respective control samples. / Land and Food Systems, Faculty of / Graduate