The reconstructive processes in a heart infarction pertain also the fibrous tissue sceleton, of which the main element are collagen fibres. The aim of the study was determination of variability of a specific collagen synthesis marker, i.e. the serum aminoterminal type III procollagen peptide (PIIINP) and its correlation with hydroxyproline (HP), hydroxylysin (HL) concentration as well as activity of creatine kinase (CK) and aspartate aminotransferase (AspAT) in serum after heart infarction. The investigations were carried out in 30 patients with a heart infarction with Q wave (group I), in 20 subjects with a heart infarction without Q wave (group II) and in 30 healthy subjects, comprising the C group. All these parameters were determined on the 1st, 2nd, 3rd, 5th and 10th day after onset of infarction. In comparison to the C group, in group I on the 1st day the PIIINP concentration was 3-fold higher and in group II it 2 1/2-fold higher (C = 4.3 +/- 1.8; I = 14.2 +/- 3.9; II = 10.4 +/- 2.0 micrograms/l; p < 0.001). In group I even on the 10th day the concentration did not return to normal values, instead in group II it reached the values x + SD in C group after 5 days. There was no significant correlation between concentration of PIIINP and all other examined parameters stated. Heart infarction with a Q wave caused a relatively highest (% of mean values in C group) increase in CK and AspAT activity, PIIINP held a medial position, while HP and HL the lowest. After infarction without a Q wave the relative elevation of PIIINP concentration was near to the AspAT and HP increase.
Conclusions: 1. the differences of serum PIIINP concentration are probably resulted by the magnitude of heart infarction. 2. During 10 days after the onset of heart infarction the serum concentration of PIIINP does not show any correlation with HP, HL and enzymatic heart infarct markers. 3. The results indirectly show, that the scar formation after heart infarction begins already on the first day.