Type I and III procollagen propeptides in growth hormone-deficient patients: effects of increasing doses of GH.
The effect of increasing doses of growth hormone on collagen synthesis in GH-treated GH-deficient patients was determined in a short-term study. The synthesis of type I and III collagen was estimated by measurements of the carboxyterminal propeptide of type I procollagen and the aminoterminal propeptide of type III procollagen. Type I collagen is mainly found in bone and type III collagen in loose connective tissue. We observed a GH dose dependency of both procollagen propeptides. Serum type I procollagen propeptide was significantly higher following GH doses of 4 and 6 IU/day for 14 days compared with 2 IU/day (normal replacement dose) (p = 0.04). Withdrawal of GH therapy for 14 days resulted in wider variation, but not significantly different from the levels at 2, 4 and 6 IU/day. A dose dependency was found regarding type III procollagen propeptide, showing significantly higher serum concentrations at a GH dose of 4 IU/day compared with 2 IU/day (p = 0.001), and of 6 IU/day compared with 4 IU/day (p = 0.001). Withdrawal of GH therapy resulted in significantly lower type III procollagen propeptide concentrations compared with those at a GH dose of 4 and 6 IU/day (p = 0.03). Serum type III procollagen propeptide increased twice as much as type I procollagen propeptide, by 47 vs 25%, at a GH dose of 6 IU/day compared with 2 IU/day. The differences between the effects on type I and type III collagen may reflect differences in secretion or turn-over rate of collagen in bone and loose connective tissue.(ABSTRACT TRUNCATED AT 250 WORDS)
Jensen
L T
LT
Department of Rheumatology 232, Hvidovre Hospital, University of Copenhagen, Denmark.
Jørgensen
J O
JO
Risteli
J
J
Christiansen
J S
JS
Lorenzen
I
I
D000293:Adolescent; D000328:Adult; D002648:Child; D003094:Collagen / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D005260:Female; D013006:Growth Hormone / Q000172:deficiency* / Q000627:therapeutic use; D006801:Humans; D008297:Male; D010446:Peptide Fragments / Q000032:analysis*; D011347:Procollagen / Q000032:analysis*; D011863:Radioimmunoassay
D010446:Peptide Fragments; D011347:Procollagen; C041876:procollagen Type III-N-terminal peptide; C042813:procollagen type I carboxy terminal peptide; D013006:Growth Hormone; D003094:Collagen