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Bone Mineral Density (BMD), Bone Mineral Content (BMC), and MMP-8 and MMP-9 Levels in Human Mandibular and Alveolar Bone: A Study in Simulated Microgravity
Exposure of astronauts and cosmonauts to microgravity conditions has been associated with several physiological changes including but not limited to an osteoporosis-like loss of bone mass. It has been reported that head-down tilt bed-rest studies mimic many of the observations seen in flights. However, to date there has been no study on the effects of mandibular bone and alveolar bone density loss in both sexes in a simulated microgravity environment. The current study was designed to determine bone mineral density (BMD) and GCF MMP-8 and MMP-9 levels in normal healthy subjects of both sexes in simulated microgravity conditions based on -6° head-down-tilt (HDT) bed rest. The subjects in this investigation were 10 male and 10 female volunteers participating in a three-week, 6° HDT bed-rest exposure. The BMD and Bone Mineral Content (BMC) of each individual were measured by dual energy X-ray absorptiometry before and during simulated microgravity. GCF MMP-8 and MMP-8 levels were measured by enzyme-linked immunosorbent assays. BMD and BMC levels were, in both genders, significantly <I>decreased</I> in simulated microgravity (although insignificantly a higher loss was observed in females as compared to males). In comparison, the MMP-8 and MMP-9 levels were significantly increased in simulated microgravity as compared to those in normal conditions (again insignificantly higher in females compared to males). Further studies are required using a larger sample size including all factors affected in simulated microgravity and true zero gravity.
Simulated Microgravity Condition, Head-down-tilt, Bone Loss, MMP-8, MMP-9, Bone Mineral Density (BMD), Bone Mineral Content (BMC)
- Gurovsky, NN, Gazenko, OG, Rudnyi, NM, Lebedev, AA and Egorov, AD. Some results of medical investigations performed during the flight of the research orbital station Salyut. Life Sci.Space Res 11, 77 (1973).
- Buckey, JC, Jr. et al. Orthostatic intolerance after spaceflight. J Appl Physiol 81,7-18 (1996).
- Hargens, AR. Recent bed rest results and countermeasure development at NASA. Acta Physiol Scand Suppl 616, 103-14 (1994).
- Di Prampero, PE and Narici, MV. Muscles in microgravity: From fibres to human motion. J Biomech 36, 403-12 (2003).
- McCarthy, Goodship A, Herzog R, Oganov V, Stussi E, Vahlensieck M. Investigation of bone changes in microgravity during long and short duration space flight: Comparison of techniques. European Journal of Clinical Investigation (2000) 30, 1044-1054.
- Turner RT. Invited Review: What do we know about the effects of spaceflight on bone? J Appl Physiol 89: 840-847, 2000.
- Bikle DD and Halloran BP. The response of bone to unloading. J Bone Miner Metab 17: 233-244, 1999.
- Vico L, Collet P, Guignandon A, Lafage-Proust MH, Thomas T, Rehailla M and Alexandre C. Effects of long-term microgravity exposure on cancellous and cortical weight-bearing bones of cosmonauts. Lancet 355: 1607-11, 2000.
- Vailas AC, Zernicke RF, Grindeland FE, Kaplansky A, Durnova BN, Li KC, and Martinez DA. Effects of spaceflight on rat humerus geometry, biomechanics and biochemistry. FASEB J 4: 47-54, 1990.
- Wronski TJ and Morey ER. Effect of spaceflight on periosteal bone formation in rats. Am J Physiol Regul Integr Comp Physiol 244: R305-R309, 1983.
- Shaw SR, Vailas AC, Grinderland RE and Zernicke RF. Effects of a 1-week spaceflight on morphological and mechanical properties of growing rats. Am J Physiol Regul Integr Comp Physiol 254: R78-R83, 1988.
- Evans GL, Morey-Holton E and Turner RT. Spaceflight has compartment- and gene-specific effects on mRNA levels for bone matrix proteins in rat femur. J Appl Physiol 84: 2132-2137, 1998.
- Bloomfield SA, Allen MR, Hogan HA, and Delp MD. Site and compartment-specific changes in bone with hindlimb unloading in mature adult rats. Bone 31: 149-157, 2002.
- Vico L, Bourrin S, Very JM, Radziszowska M, Collet P and Alexandre C. Bone changes in 6-month-old rats after head down suspension and a reambulation period. J Appl Physiol 79: 1426- 1433, 1995.
- Harris SA, Zhang M, Kidder LS, Evans GL, Spelsberg TC and Turner RT. Effects of orbital spaceflight on human osteoblastic cell physiology and gene expression. Bone 26: 325-331, 2000.
- Collet P, Uebelhart D, Vico L, Moro L, Hartmann D, Roth M, et al. (1997). Effects of 1- and 6-month spaceflight on bone mass and biochemistry in two humans. Bone 20:547-551.
- Rambaut PC, Leach CS, Whedon GD (1979). A study of metabolic balance in crew members of Skylab IV. Acta Astronautica 6:1113- 1122.
- Minaire P, Meunier PJ, Edouard C, Bernard J, Courpron P, Bourret J. Quantitative histological data on disuse osteoporosis. Calcif Tissue Int 1974; 17: 57-73.
- Jouanny P, Guillemin F, Kuntz C, Jeandel C, Pourel J. Environmental and genetic factors affecting bone mass: Similarity of bone density among members of healthy families. Arthritis Rheum 1995; 38: 61-67.
- Arden NK, Spector TD. Genetic influences on muscle strength, lean body mass, and bone mineral density: A twin study. J Bone Miner Res 1997; 12: 2076-81.
- Hannan MT, Felson DT, Dawson-Hughes B, Tucker KL, Cupples LA, Wilson PW, Kiel DP. Risk factors for longitudinal bone loss in elderly men and women: The Framingham Osteoporosis Study. J Bone Miner Res 2000; 15(4):710-20.
- Leblanc AD, Schneider VS, Evans HJ, Engelbretson DA, Krebs JM. Bone mineral density and recovery after 17 weeks of bed rest. J Bone Miner Res 1990; 5: 843-50.
- White RJ, Blomqvist CG. Central venous pressure and cardiac function during spaceflight. J Appl Physiol 1998; 85: 738-46.
- Woessner JF, Jr. Matrix metalloproteinases and their inhibitors in connective tissue remodeling. FASEB J 1991;5:2145-2154.
- Birkedal-Hansen H. Role of matrix metalloproteinases in human periodontal diseases. J Periodontol 1993;64(5 Suppl):474-484.
- Salo T, Makela M, Kylmaniemi M, et al. Expression of matrix metalloproteinase-2 and -9 during early human wound healing. Lab. Invest 1994;70:176-182.
- Golub LM, Lee HM, Greenwald RA, et al. A matrix metalloproteinase inhibitor reduces bone-type collagen degradation fragments and specific collagenases in gingival crevicular fluid during adult periodontitis. Inflamm. Res 1997;46:310-319.
- Teng YT, Sodek J, McCulloch CA. Gingival crevicular fluid gelatinase and its relationship to periodontal disease in human subjects. J Periodontal Res 1992;27:544-552.
- Rai B, Kharb S, Jain R, Anand SC (2008). Biomarkers of periodontitis in oral fluids. J Oral Sci 50, 53-56.
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