Preosteoblast production in COSMOS 2044 rats: short-term recovery of osteogenic potential

• Published in: Journal of applied physiology (1985) Vol. 73; no. 2 Suppl; p. 14S
• Main Authors: Garetto, L P, Morey, E R, Durnova, G N, Kaplansky, A S, Roberts, W E
• Format: Journal Article
• Language: English
• Published: United States 01.08.1992
• Subjects: Animals; Bone Development - physiology; Cell Differentiation - physiology; Cell Nucleus - physiology; Cell Nucleus - ultrastructure; Gingiva - growth & development; Gingiva - physiology; Kinetics; Ligaments - growth & development; Ligaments - physiology; Male; Osteoblasts - physiology; Rats; Rats, Inbred Strains; Space Flight; Stem Cells - physiology; NASA Center ARC; NASA Discipline Musculoskeletal; Non-NASA Center
• ISSN: 8750-7587
• DOI: 10.1152/jappl.1992.73.2.S14

The influence of a 13.8-day spaceflight and approximately 8.5-11 h of recovery at 1 g on fibroblast-like osteoblast precursor cells was assessed in the periodontal ligament of rat maxillary first molars. Preosteoblasts (C + D cells), less differentiated progenitor cells (A + A' cells), and nonosteogenic fibroblast-like cells (B cells) were identified by nuclear volume analysis (i.e., A + A' = 40-79 microns 3; B = 80-119 microns 3; C + D greater than or equal to 120 microns 3). No differences were observed among flight (F), synchronous (SC), vivarium, and basal control groups in the A + A' (F: 28.0 +/- 3.7 vs. SC: 27.4 +/- 2.2), B (F: 33.1 +/- 1.4 vs. SC: 32.4 +/- 2.4), or C + D (F: 38.4 +/- 4.5 vs. SC: 39.2 +/- 1.6) cell compartments (mean +/- SE, n = 5). Compared with previous spaceflight experiments, the present data are consistent with a postflight response to replenish preosteoblasts and restore periodontal ligament osteogenic potential. These data emphasize the need to 1) unequivocally determine the flight effect by killing the animals in-flight and 2) further assess the postflight recovery phenomenon.