Endogenous Catecholamine Mobilization and the Shift to Anaerobic Energy Production in the Acutely Ischemic Myocardium

Author(s):  
A. Wollenberger ◽  
E. -G. Krause ◽  
Liane Shahab
1984 ◽  
Vol 56 (2) ◽  
pp. 520-525 ◽  
Author(s):  
G. A. Brooks ◽  
C. M. Donovan ◽  
T. P. White

o assess the effects of gradient and running speed on efficiency of exercise, and to evaluate contributions of oxidative and anaerobic energy production (Ean) during locomotion, two sets of experiments were performed. The caloric expenditures of rats were determined from O2 consumption (VO2) while they ran at three speeds (13.4, 26.8, and 43.1 m/min) on five grades (1, 5, 10, 15, and 20%). In addition, lactate turnover (LaT) and oxidation (Laox) were determined on rats at rest or during running at 13.4 and 26.8 m/min on 1% grade, respectively. Lactate production not represented in the VO2 (i.e., Ean) was calculated from the LaT not accounted for by oxidation [(LaT an) = LaT-Laox)]. The Ean was calculated as: Ean = [LaT an(mumol/min)] [1.38 ATP/La] [11 mcal/mumol ATP]. Gross efficiency of exercise (the caloric equivalent of external work/caloric equivalent of VO2 X 100) ranged from 1.7 to 4.5%. Apparent efficiency (the inverse of the regression of caloric equivalent of VO2 on the caloric equivalent of work X 100) ranged from 20.5 to 26.4% and reflected the metabolic response of rats to applied external work. The contribution of Ean to total energy turnover ranged from 1.6% at rest to 0.8% during running at 13.4 m/min on a 1% grade. Despite active LaT during steady-state exercise, Ean contributes insignificantly to total energy transduction, because over 70% of the lactate produced is removed through oxidation. VO2 adequately represents metabolism under these conditions.


2016 ◽  
Vol 11 (6) ◽  
pp. 810-815 ◽  
Author(s):  
Clare L. Minahan ◽  
Danielle J. Pirera ◽  
Beth Sheehan ◽  
Luke MacDonald ◽  
Phillip M. Bellinger

This study compared determinants of a 30-s all-out paddling effort (30-s sprint-paddling test) between junior surfboard riders (surfers) of varying ability. Eight competitive (COMP) and 8 recreational (REC) junior male surfers performed a 30-s sprint-paddling test for the determination of peak sprint power and accumulated O2 deficit. Surfers also performed an incremental-paddling test for the determination of the O2 uptake–power output relationship that was subsequently used to calculate the accumulated O2 deficit for the 30-s sprint-paddling test. During the 30-s sprint-paddling test, peak sprint power (404 ± 98 vs 292 ± 56 W, respectively, P = .01) and the accumulated O2 deficit (1.60 ± 0.31 vs 1.14 ± 0.38 L, respectively, P = .02) were greater in COMP than in REC surfers, whereas peak O2 uptake measured during the incremental-paddling test was not different (2.7 ± 0.1 vs 2.5 ± 0.2 L/min, respectively, P = .11). The higher peak sprint power and larger accumulated O2 deficit observed in COMP than in REC surfers during a 30-s sprint paddling test suggest that surfing promotes development of the anaerobic energy systems. Furthermore, peak sprint power determined during 30 s of sprint paddling may be considered a sensitive measure of surfing ability or experience in junior male surfers.


1999 ◽  
Vol 67 (9) ◽  
pp. S655
Author(s):  
Thomas A. Churchill ◽  
Jennifer L. Sheasgreen ◽  
Tze-Feng Chong ◽  
Christine M. Fedorow ◽  
David F. Mercer ◽  
...  

1993 ◽  
Vol 265 (1) ◽  
pp. R157-R165 ◽  
Author(s):  
H. O. Portner ◽  
D. M. Webber ◽  
R. K. O'Dor ◽  
R. G. Boutilier

The concentrations of intermediate and end products of anaerobic energy metabolism and of free amino acids were determined in mantle musculature and blood sampled from cannulated, unrestrained squid (Loligo pealei, Illex illecebrosus) under control conditions, after fatigue from increasing levels of exercise, and during postexercise recovery. Phosphagen depletion, accumulation of octopine (more so in Illex than in Loligo), and accumulation of succinate indicate that anaerobic metabolism contributes to energy production before fatigue. Proline was a substrate of metabolism in Loligo, as indicated by its depletion in the mantle. In both species, there was no evidence of catabolism of ATP beyond AMP. A comparison of the changes in the free and total levels of adenylates and the phosphagen indicates an earlier detrimental effect of fatigue on the energy status in Loligo. The acidosis provoked by octopine formation in Illex was demonstrated to promote the use of the phosphagen and to protect the free energy change of ATP such that the anaerobic scope of metabolism during swimming is extended and expressed more in Illex than in Loligo. In both species, there was no decrease in the sum of phospho-L-arginine, octopine, and L-arginine, and thus no release of octopine from the mantle, thereby supporting our earlier claim that octopine and associated protons are recycled in the mantle tissue. Overall, the metabolic strategy of Loligo is much less disturbing for the acid-base status. This strategy and the alternative strategy of Illex to keep acidifying protons in the tissue may be important for the protection of hemocyanin function in the two species.


2010 ◽  
Vol 109 (5) ◽  
pp. 1562-1564 ◽  
Author(s):  
Sébastien Ratel ◽  
Anne Tonson ◽  
Patrick J. Cozzone ◽  
David Bendahan

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