Synthesis of type I collagen in healing wounds in humans.
 To quantify wound healing in surgical patients, samples of wound fluid were collected through a silicone rubber tube for 7 postoperative days and their concentrations of the carboxyterminal propeptide of type I procollagen (PICP) and the aminoterminal propeptide of type III procollagen (PIIINP) were measured with specific radioimmunoassays.
 The mean concentration of PICP in would fluid on day 1 was 207 +/- 92 (SD) micrograms/L, and on day 2 908 +/- 469 micrograms/L (p less than 0.001, signed rank test).
 On day 7, the mean concentration reached was 380 times higher than that of day 1 (79,330 +/- 54,151 micrograms/L).
 Only one peak of PICP antigenicity, corresponding to the intact propeptide as set free during synthesis of type I procollagen, was detected on Sephacryl S-300 gel filtration analysis of wound fluid samples.
 The mean concentration of PIIINP was 70 +/- 61 micrograms/L on day 1, 86 +/- 88 micrograms/L on day 2, and 180 +/- 129 micrograms/L on day 3 (p less than 0.001 when compared with day 1).
 Finally on day 7, a 250-fold concentration (17,812 +/- 9839 micrograms/L), compared with day 1, was reached.
 Methods described in the present paper allow separate and repetitive quantification of the synthesis of both type I and type III procollagen during human wound healing.
