The influence of a 13.8-day spaceflight and ~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 μm3; B = 80-119 μm3; C + D ≥ 120 μm3). 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 (means ± 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.
|Original language||English (US)|
|Journal||Journal of Applied Physiology|
|Issue number||2 SUPPL.|
|State||Published - Jan 1 1992|
- cell differentiation
ASJC Scopus subject areas
- Physiology (medical)