Biosynthetic growth hormone changes the collagen and elastin contents and biomechanical properties of the rat aorta.
The biomechanical and biochemical properties of aortas from female rats treated with biosynthetic human GH (b-hGH) for 80 days were investigated. b-hGH was administered at a dose of 5 mg.kg-1.d-1. Treatment with b-hGH increased the body weight by 75% and the diameter of the aorta by 14% compared with the control group. The concentration of collagen and the relative amount of collagen type I were increased, and the concentration of elastin was decreased. Aortas from the b-hGH-treated group showed increased extensibility in the regions corresponding to physiological load values (i.e. 100-200 mmHg), and increased stiffness in regions with higher load values. The increased extensibility at low load values corresponds well with the loss of elastin, and the increased stiffness at higher load values with the increase of collagen and relative increase of collagen type I. These alterations induced by the growth hormone treatment might influence the elasticity and recoiling properties of the aorta.
Brüel
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Department of Connective Tissue Biology, University of Aarhus, Denmark.
Oxlund
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D000818:Animals; D001011:Aorta / Q000033:anatomy & histology / Q000378:metabolism* / Q000502:physiology; D001786:Blood Glucose / Q000032:analysis; D003094:Collagen / Q000378:metabolism*; D004549:Elastin / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D013006:Growth Hormone / Q000494:pharmacology*; D009929:Organ Size / Q000187:drug effects; D009994:Osmolar Concentration; D051381:Rats; D011919:Rats, Inbred Strains; D013314:Stress, Mechanical
D001786:Blood Glucose; D013006:Growth Hormone; D003094:Collagen; D004549:Elastin