Annual serum PICP and ICTP and antler growth in female reindeer (Rangifer tarandus tarandus)

Annual cycle of type I collagen formation and degradation and antler growth was studied in six adult female reindeer, Rangifer tarandus tarandus. Bloo d samples were collected twice a week during 1 year. Antler length was meas ured weekly during the antler growth period. An assay for human PICP, the c arboxyterminal propeptide of type I procollagen, was used as an indicator o f type I collagen formation and an assay for bovine ICTP, the carboxytermin al telopeptide of type I collagen, as an indicator of type I collagen degra dation. PICP was clearly increased during the antler growth period. Also IC TP was slightly elevated during antler growth, but the highest values were found in autumn and winter. Our statistical analysis revealed that changes in lagged values (from 3 to 6 weeks) of PICP could be linked to the subsequ ent changes in the growth rate of the antler, although the highest values o f PICP were found during the final third of antler growth. ICTP had signifi cant predictive power as well, but the connection with the growth rate seem ed more immediate than that of PICP. In conclusion, antler collagen synthes is can be predicted by PICP, but also ICTP was related to the antler growth . (C) 1999 Elsevier Science Inc. All rights reserved.