T. Natsuume et al., TEMPORAL AND SPATIAL EXPRESSION OF TRANSFORMING-GROWTH-FACTOR-BETA INTHE HEALING PATELLAR LIGAMENT OF THE RAT, Journal of orthopaedic research, 15(6), 1997, pp. 837-843
We investigated the temporal and spatial expression of transforming gr
owth factor-beta in the healing patellar ligament of the rat by immuno
histochemistry. The mid-portion of the medial half of the patellar lig
ament in 14-week-old male Wistar rats was cut transversely with a scal
pel. On day 1 after ligament injury, diffuse staining for transforming
growth factor-beta was observed in the extracellular matrix filling t
he wound, and the staining in the adjacent ligament tissue was as weak
as it was in the normal ligament. On day 3, the intensity of the diff
use extracellular staining decreased, and the staining was observed in
correspondence with the cellular distribution in the wound site and i
n the adjacent uninjured ligament tissue. On day 7, the intense staini
ng was widely distributed over the whole length of the ligament tissue
. On day 28, the staining for transforming growth factor-beta was stil
l observed at the wound site and in the adjacent uninjured ligament ti
ssue, where the staining was reduced in intensity but still stronger t
han it was in the normal ligament. On day 56, the expression of transf
orming growth factor-beta was still detectable at the wound site; howe
ver, in the adjacent uninjured ligament tissue, it had almost subsided
to the normal level. The results of the present study suggest that li
gament healing may be accompanied by extensive changes in the expressi
on of transforming growth factor-p over the whole length of ligament t
issue.