The utility of skeletal troponin I (sTnI) as a plasma marker of skeletal muscle damage after exercise was compared against creatine kinase (CK), myoglobin (Mb), and myosin heavy chain (MHC) fragments. These markers were serially measured in normal physical education teacher trainees after four different exercise regimens: 20 min of level or downhill (16% decline) running (intensity: 70% maximal O2 uptake), high-force eccentric contractions (70 repetitions), or high-force isokinetic concentric contractions of the quadriceps group (40 repetitions). Eccentrically biased exercise (downhill running and eccentric contractions) promoted greater increases in all parameters. The highest plasma concentration were found after downhill running (median peaks: 309 U/l CK concentration (-CK-)), 466 microgram/l Mb concentration (-Mb-), 1,021 microU/l MHC concentration (-MHC-), and 27.3 microgram/l sTnI concentration ([sTnI]). Level running produced a moderate response (median peaks: 178 U/l -CK-, 98 microgram/l -Mb-, 501 microU/l -MHC-, and 6.6 microgram/l [sTnI]), whereas the concentric contraction protocol did not elicit significant changes in any of the markers assayed. sTnI increased and peaked in parallel to CK and stayed elevated (>2.2 microgram/l) for at least 1-2 days after exercise. In contrast to MHC, sTnI is an initial, specific marker of exercise-induced muscle injury, which may be partly explained by their different intracellular compartmentation with essentially no (MHC <0.1%) or a small soluble pool (sTnI: median 3.4%).

No abstract

No abstract

overall alternating arrangement of ligands (R,R,S,S), along the c-crystal axis results[41. Thus, mixing the pure quasienantiomers (1s)-1 and (1R)-3 produces the quasiracemate as a highly ordered columnar structure with a onedimensional (Rh,Rh,Ir,Ir)chain of central atoms. The Rh-Rh, Ir-IF, and Rh-Ir distances are 3.36, 3.36, and 3.43 (k0.02) A, respectively. In the quasiracemate the metal chain is not strictly linear, since the Rh-Rh and Ir-Ir moieties are slightly displaced in the crystal lattice; the distance between the axes, which contain all Rh and Ir atoms, respectively, is 0.6 A.The pair-wise stacking in the crystalline quasiracemate enforced by the chirality of the molecules represents a new type of one-dimensional metal chainI5I. The tailor-made synthesis of quasiracemates appears, therefore, to be a highly promising method for the construction of collective solid-state structures having alternating molecular parameters. Received: December 1, 1982 [Z 214 IEI German version: Angew. Chem. 95 (1983) 327 [I] a) V. Schurig, Inorg. Chem. I1 (1972) 736; b) Angew. Chem. 93 (1981) 806; Angew. Chem. Int. Ed. Engl. 20 (1981) 807.