|Budget Amount *help
¥1,800,000 (Direct Cost : ¥1,800,000)
Fiscal Year 1998 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1997 : ¥1,200,000 (Direct Cost : ¥1,200,000)
We investigated the limb long-bone diaphyses of various-aged bovines, goats, pigs, and sheep by transmitted light, scanning electron, transmitted elect'ron microscopy, and enegy-dispersive X-ray microanalysis.
In a 3-rnonth
fetus bovine, 3-4 concentric layers of laminar bone appeared around the bone marrow and 25-26 layers were seen in a new-born calf. In a 1-year-old ox, osteons appeared in the inner-third zone, however, the laminar bone was retained yet in a 12-year-old cow. The hypercalcified center of laminar bone, so-called a bright line, scattered relatively large granular and fine fibrillar structures. After formation of this line, woven bone and lamellar bone were formed on the line. The appositional volume was larger in the endosteum than the periosteum side. There were a few osteocytes in the bright line, but the cell lacunae were larger than the normal lacunae. Thus, the formation of bone matrix may somewhat differ from each other. From the bright line, larger amounts of Na and S elements were detected.
In Van-Gieson staining for collagen fibrils, the bright line showed no staining. In H-E and AZAN staining, the line was distinguishable from the woven and lamellar bones, and also differed from them in the younger laminar bone stained with toluidin blue. However, we can not identified the organic elements of the granular and fibrillar structures found in the bright line.
In the formation of limb-long bones in young goats, pigs, and sheep, laminar bone similar to that of bovines was also observed. The laminar bone was rapidly formed and osteons that should form Haversian bone did not appear in the laminar bone for a certain period of time after birth. The appearance was earlier seen in pigs and latest in bovines as a large animal.