Growth and maturational changes in dense fibrous connective tissue following 14 days of rhGH supplementation in the dwarf rat.
The purpose of this study was to investigate the impact of recombinant human growth hormone (rhGH) on patella tendon (PT), medial collateral ligament (MCL), and lateral collateral ligament (LCL) on collagen growth and maturational changes in dwarf GH-deficient rats. Twenty male Lewis mutant dwarf rats, 37 days of age, were randomly assigned to Dwarf + rhGH (n = 10) and Dwarf + vehicle (n = 10) groups. The GH group received 1.25 mg rhGH/kg body wt twice daily for 14 days. rhGH administration stimulated dense fibrous connective tissue growth, as demonstrated by significant increases in hydroxyproline specific activity and significant decreases in the non-reducible hydroxylysylpyridinoline (HP) collagen cross-link contents. The increase in the accumulation of newly accreted collagen was 114, 67, and 117% for PT, MCL, and LCL, respectively, in 72 h. These findings suggest that a short course rhGH treatment can affect the rate of new collagen production. However, the maturation of the tendon and ligament tissues decreased 18-25% during the rapid accumulation of de novo collagen. We conclude that acute rhGH administration in a dwarf rat can up-regulate new collagen accretion in dense fibrous connective tissues, while causing a reduction in collagen maturation.
Kyparos
Antonios
A
Connective Tissue Physiology Laboratory, Department of Biology and Biochemistry, University of Houston, Houston, TX 77204-5001, USA.
Orth
Michael W
MW
Vailas
Arthur C
AC
Martinez
Daniel A
DA
D000818:Animals; D003094:Collagen / Q000378:metabolism; D003238:Connective Tissue / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology*; D004392:Dwarfism / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D019382:Human Growth Hormone / Q000494:pharmacology*; D006801:Humans; D006909:Hydroxyproline / Q000378:metabolism; D008022:Ligaments / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008297:Male; D051381:Rats; D011917:Rats, Inbred Lew; D011922:Rats, Mutant Strains; D011994:Recombinant Proteins / Q000494:pharmacology; D013710:Tendons / Q000187:drug effects / Q000378:metabolism / Q000473:pathology
D011994:Recombinant Proteins; D019382:Human Growth Hormone; D003094:Collagen; D006909:Hydroxyproline