436 EFFECT OF HIGH-INTENSITY CYCLE EXERCISE AND ACID-BASE BALANCE ON THE PROPORTION OF FREE AND TOTAL INSULIN-LIKE GROWTH FACTOR-1 IN HUMAN SERUM

1993 ◽  
Vol 25 (Supplement) ◽  
pp. S77
Author(s):  
S. E. Gordon ◽  
W. J. Kraemer ◽  
J. M. Lynch ◽  
N. H. Vos
Keyword(s):  
Growth Factor ◽  
Human Serum ◽  
High Intensity ◽  
Insulin Like Growth Factor ◽  
Acid Base Balance ◽  
Acid Base ◽  
Cycle Exercise ◽  
Base Balance

Does low serum carnosinase activity favor high-intensity exercise capacity?

2014 ◽  
Vol 116 (5) ◽  
pp. 553-559 ◽  
Author(s):  
Audrey Baguet ◽  
Inge Everaert ◽  
Benito Yard ◽  
Verena Peters ◽  
Johannes Zschocke ◽  
...  
Keyword(s):  
High Intensity ◽  
Genetic Selection ◽  
High Intensity Exercise ◽  
Acid Base Balance ◽  
Acid Base ◽  
Long Distance ◽  
Double Blind ◽  
Maximal Power Output ◽  
Cross Sectional ◽  
Base Balance

Given the ergogenic properties of β-alanyl-L-histidine (carnosine) in skeletal muscle, it can be hypothesized that elevated levels of circulating carnosine could equally be advantageous for high-intensity exercises. Serum carnosinase (CN1), the enzyme hydrolyzing the dipeptide, is highly active in the human circulation. Consequently, dietary intake of carnosine usually results in rapid degradation upon absorption, yet this is less pronounced in subjects with low CN1 activity. Therefore, acute carnosine supplementation before high-intensity exercise could be ergogenic in these subjects. In a cross-sectional study, we determined plasma CN1 activity and content in 235 subjects, including 154 untrained controls and 45 explosive and 36 middle- to long-distance elite athletes. In a subsequent double-blind, placebo-controlled, crossover study, 12 men performed a cycling capacity test at 110% maximal power output (CCT 110%) following acute carnosine (20 mg/kg body wt) or placebo supplementation. Blood samples were collected to measure CN1 content, carnosine, and acid-base balance. Both male and female explosive athletes had significantly lower CN1 activity (14% and 21% lower, respectively) and content (30% and 33% lower, respectively) than controls. Acute carnosine supplementation resulted only in three subjects in carnosinemia. The CCT 110% performance was not improved after carnosine supplementation, even when accounting for low/high CN1 content. No differences were found in acid-base balance, except for elevated resting bicarbonate following carnosine supplementation and in low CN1 subjects. In conclusion, explosive athletes have lower serum CN1 activity and content compared with untrained controls, possibly resulting from genetic selection. Acute carnosine supplementation does not improve high-intensity performance.

Acid-base homeostasis parallels anabolism in surgically stressed rats treated with GH and IGF-I

1996 ◽  
Vol 270 (6) ◽  
pp. E968-E974
Author(s):  
S. J. Evans ◽  
H. C. Lo ◽  
D. M. Ney ◽  
T. C. Welbourne
Keyword(s):  
Growth Factor ◽  
Acid Production ◽  
Surgical Stress ◽  
Acid Base Balance ◽  
Acid Base ◽  
Sulfuric Acid Production ◽  
Igf I ◽  
Base Balance ◽  
Glutaminase Activity ◽  
Growth Factor Treatment

The effect of a standard surgical stress and subsequent total parenteral nutrition (TPN) treatment on systemic acid-base balance was assessed in four groups of rats: TPN controls, TPN coinfused with recombinant human insulin-like growth factor I (rhIGF-I, 800 micrograms/day), TPN with recombinant human growth hormone (rhGH, 800 micrograms in two divided daily sc doses), and combined rhGH plus rhIGF-I (800 + 800 micrograms/day). After the 6-day time course, TPN controls exhibited a systemic metabolic acidosis (HCO3- = 20.4 +/- 0.4 mM) and lost 7 g body wt/6 days. Either growth factor ameliorated the acidosis (rhGH = 22.6 +/- 0.6 and IGF-I = 22.0 +/- 0.5 mM) and promoted weight gain (11 +/- 2 and 10 +/- 3 g/6 days, respectively). Combined growth factor treatment, rhGH+rhIGF-I, restored acid-base balance (HCO3- = 24.7 +/- 0.6 mM) and exhibited an additive effect on weight gain (25 +/- 3 g/6 days). Ammonium and sulfate excretion as indexes of renal acid excretion and systemic sulfuric acid production, respectively, were highest in the TPN control, Growth factors alone reduced sulfuric acid production, whereas combined growth factor treatment reduced acid production and eliminated acid excretion despite elevated renal glutaminase activity. However, renal cortical glutamate content was elevated in the combined growth factor treatment (10.6 +/- 0.7 vs. 7.3 +/- 0.5 rhGH+rhIGF-1 vs. TPN, P < 0.05), consistent with repression of the elevated glutaminase activity. These findings point to an important role for acid-base homeostasis in the anabolic response and are consonant with an additive effect of growth factors, rhGH+rhIGF-I, in correcting the metabolic acidosis associated with surgical stress.

scholarly journals Ingestion of Sodium Bicarbonate (NaHCO3) Following a Fatiguing Bout of Exercise Accelerates Postexercise Acid-Base Balance Recovery and Improves Subsequent High-Intensity Cycling Time to Exhaustion

2017 ◽  
Vol 27 (5) ◽  
pp. 429-438 ◽  
Author(s):  
Lewis A. Gough ◽  
Steven Rimmer ◽  
Callum J. Osler ◽  
Matthew F. Higgins
Keyword(s):  
Sodium Bicarbonate ◽  
Body Mass ◽  
High Intensity ◽  
Recovery Period ◽  
Time To Exhaustion ◽  
Acid Base Balance ◽  
Acid Base ◽  
Base Balance ◽  
Experimental Trials ◽  
Cycling Time

This study evaluated the ingestion of sodium bicarbonate (NaHCO3) on postexercise acid-base balance recovery kinetics and subsequent high-intensity cycling time to exhaustion. In a counterbalanced, crossover design, nine healthy and active males (age: 23 ± 2 years, height: 179 ± 5 cm, body mass: 74 ± 9 kg, peak mean minute power (Wpeak) 256 ± 45 W, peak oxygen uptake (V̇O2peak) 46 ± 8 ml.kg-1.min-1) performed a graded incremental exercise test, two familiarization and two experimental trials. Experimental trials consisted of cycling to volitional exhaustion (TLIM1) at 100% WPEAK on two occasions (TLIM1 and TLIM2) interspersed by a 90 min passive recovery period. Using a double-blind approach, 30 min into a 90 min recovery period participants ingested either 0.3 g.kg-1 body mass sodium bicarbonate (NaHCO3) or a placebo (PLA) containing 0.1 g.kg-1 body mass sodium chloride (NaCl) mixed with 4 ml.kg-1 tap water and 1 ml.kg-1 orange squash. The mean differences between TLIM2 and TLIM1 was larger for PLA compared with NaHCO3 (-53 ± 53 vs. -20 ± 48 s; p = .008, d = 0.7, CI =-0.3, 1.6), indicating superior subsequent exercise time to exhaustion following NaHCO3. Blood lactate [Bla-] was similar between treatments post TLIM1, but greater for NaHCO3 post TLIM2 and 5 min post TLIM2. Ingestion of NaHCO3 induced marked increases (p < .01) in both blood pH (+0.07 ± 0.02, d = 2.6, CI = 1.2, 3.7) and bicarbonate ion concentration [HCO3-] (+6.8 ± 1.6 mmo.l-1, d = 3.4, CI = 1.8, 4.7) compared with the PLA treatment, before TLIM2. It is likely both the acceleration of recovery, and the marked increases of acid-base after TLIM1 contributed to greater TLIM2 performance compared with the PLA condition.

Effects of Exercise and Alkalosis on Serum Insulin-Like Growth Factor I and IGF-Binding Protein-3

2000 ◽  
Vol 25 (2) ◽  
pp. 127-138 ◽  
Author(s):  
William J. Kraemer ◽  
Fred S. Harman ◽  
Netty H. Vos ◽  
Scott E. Gordon ◽  
Bradley C. Nindl ◽  
...  
Keyword(s):  
Serum Insulin ◽  
Anaerobic Exercise ◽  
Acid Base Balance ◽  
Acid Base ◽  
Cycle Exercise ◽  
Placebo Condition ◽  
Base Balance ◽  
Igf Binding ◽  
Igf Binding Protein ◽  
Induced Alkalosis

This investigation examines the effects of orally induced alkalosis on serum IGF-1 and IGFBP3 concentrations in response to an acute 90-s bout of high intensity cycle exercise. Ten healthy, active men, ages 24.60 ± 4.90 years, participated in a randomized, doubleblind, counterbalanced trial order with a cross-over design. Subjects ingested an experimental bicarbonate solution or a placebo solution. Blood was sampled at baseline; pre-exercise: and 0, 5, 10, and 30 min postexercise. The pH between groups for pre-exercise and postexercise time points differed significantly (p < .05) in the experimental condition (from 7.42 ± 0.01 to 7.35 ± 0.02) versus the placebo condition (from 7.36 ± 0.01 to 7.25 ± 0.03). Increases in IGF-1 over resting conditions occurred with placebo conditions at 5 and 10 min postexercise and in the experimental condition at 5 min postexercise. Concentrations of IGFBP3 were elevated above baseline at IP in both experimental and placebo conditions. Key Words: hormones, physical stress, anaerobic exercise, acid-base balance, pH

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