Biomaterial Database

Growth hormone stimulates bone formation and strength of cortical bone in aged rats. 1995

T T Andreassen, and P H Jørgensen, and A Flyvbjerg, and H Orskov, and H Oxlund

Department of Connective Tissue Biology, University of Aarhus, Denmark.

The influence of growth hormone on bone formation, mechanical strength, and composition has been investigated in femur middiaphyseal cortical bone from 2-year-old male rats. The rats were given biosynthetic human growth hormone (bhGH) at 2.7 mg/kg/day in two daily injections for 20, 40, or 80 days, and all animals were killed 80 days after the start of bhGH administration. Control animals were given saline. All animals were labeled with tetracycline on days 41 and 69. Only in the bhGH-80-day group was subperiosteal tetracycline double labeling seen all around the femur diaphysis, and this pattern was found in all animals of the group. Double labeling subperiosteally at the posteromedial aspect was found in all animals of the experiment, but compared with the control group, a 400% and an 800% increase in mineral apposition rate was seen in the bhGH-40-day and bhGH-80-day groups, respectively. Light microscopy and polarization microscopy showed that this newly deposited bone was organized in the same concentric lammellae and had the same direction of the collagen fibers when compared with the surrounding bone formed before the start of bhGH injections. The cortical bone cross-sectional area was increased in the bhGH-40-day and bhGH-80-day groups. At the endosteum, scattered labeling was found in animals from all groups, and no differences in medullary cross-sectional areas were seen. The mechanical analysis revealed an increased mechanical strength of the whole diaphyseal bone after bhGH administration. When the data were corrected for dimensions of the diaphyseal bone, no differences in intrinsic mechanical properties of the bone tissue were found. No differences in apparent density of dry defatted bone, ash, and collagen were seen, whereas apparent density of dry defatted bone minus ash was decreased in all groups given bhGH. Correspondingly, a slight increase in ash concentrations of the bhGH-injected animals was seen. bhGH administration also increased the body weight, muscle mass, and total serum IGF-I and thyroxine concentrations.

UI	MeSH Term	Description	Entries
D007334	Insulin-Like Growth Factor I	A well-characterized basic peptide believed to be secreted by the liver and to circulate in the blood. It has growth-regulating, insulin-like, and mitogenic activities. This growth factor has a major, but not absolute, dependence on GROWTH HORMONE. It is believed to be mainly active in adults in contrast to INSULIN-LIKE GROWTH FACTOR II, which is a major fetal growth factor.	IGF-I,Somatomedin C,IGF-1,IGF-I-SmC,Insulin Like Growth Factor I,Insulin-Like Somatomedin Peptide I,Insulin Like Somatomedin Peptide I
D008297	Male		Males
D008856	Microscopy, Fluorescence	Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.	Fluorescence Microscopy,Immunofluorescence Microscopy,Microscopy, Immunofluorescence,Fluorescence Microscopies,Immunofluorescence Microscopies,Microscopies, Fluorescence,Microscopies, Immunofluorescence
D008859	Microscopy, Polarization	Microscopy using polarized light in which phenomena due to the preferential orientation of optical properties with respect to the vibration plane of the polarized light are made visible and correlated parameters are made measurable.	Microscopy, Polarized Light,Polarization Microscopy,Light Microscopies, Polarized,Light Microscopy, Polarized,Microscopies, Polarization,Microscopies, Polarized Light,Polarization Microscopies,Polarized Light Microscopies,Polarized Light Microscopy
D001798	Blood Proteins	Proteins that are present in blood serum, including SERUM ALBUMIN; BLOOD COAGULATION FACTORS; and many other types of proteins.	Blood Protein,Plasma Protein,Plasma Proteins,Serum Protein,Serum Proteins,Protein, Blood,Protein, Plasma,Protein, Serum,Proteins, Blood,Proteins, Plasma,Proteins, Serum
D001835	Body Weight	The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.	Body Weights,Weight, Body,Weights, Body
D001846	Bone Development	The growth and development of bones from fetus to adult. It includes two principal mechanisms of bone growth: growth in length of long bones at the epiphyseal cartilages and growth in thickness by depositing new bone (OSTEOGENESIS) with the actions of OSTEOBLASTS and OSTEOCLASTS.	Bone Growth
D005269	Femur	The longest and largest bone of the skeleton, it is situated between the hip and the knee.	Trochanter,Greater Trochanter,Lesser Trochanter,Femurs,Greater Trochanters,Lesser Trochanters,Trochanter, Greater,Trochanter, Lesser,Trochanters,Trochanters, Greater,Trochanters, Lesser
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000375	Aging	The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.	Senescence,Aging, Biological,Biological Aging