Increased mechanical strength of left colon in old rats treated with growth hormone.
The effects of treatment with 2.7 mg biosynthetic human growth hormone (b-hGH; 2.7 mg/kg b.w./day) for 80 days on the biomechanical properties and collagen deposition of the left colon were studied in 27-month-old male rats. The b-hGH-treated rats increased in body weight by 17%, and the wet weight of colon by 31%. The defatted dry weight and the hydroxyproline content of the left colon were increased by 41 and 29%, respectively, compared with controls. The biomechanical analysis showed that the maximum load and stiffness of the left colonic specimens in the b-hGH-treated group were enhanced by 27 and 60%, respectively, and the strain at maximum load was 24% less than in the control group. The maximum 'stress' and stiffness were 40 and 73% higher, respectively, than in the controls. Histological examination demonstrated that the mean crypt heights was 9% higher in the b-hGH-treated rats than in the controls. Consequently, treatment of old rats with b-hGH may increase the strength, collagen deposition and mucosal crypt height of the left colon.
Christensen
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H
Department of Connective Tissue Biology, University of Aarhus, Denmark.
Andreassen
T T
TT
Oxlund
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H
D000375:Aging / Q000502:physiology*; D000818:Animals; D001696:Biomechanical Phenomena; D001835:Body Weight / Q000187:drug effects; D003094:Collagen / Q000378:metabolism; D003106:Colon / Q000033:anatomy & histology / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D013006:Growth Hormone / Q000494:pharmacology*; D006909:Hydroxyproline / Q000032:analysis; D008297:Male; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar
D013006:Growth Hormone; D003094:Collagen; D006909:Hydroxyproline