犬の粘膜骨膜フラップ手術後の骨膜における微小血管応答：血管新生と骨吸収・形成

Microvascular response in the periosteum following mucoperiosteal flap surgery in dogs: angiogenesis and bone resorption and formation.

• Takahiro Nobuto
• Fumihiko Suwa
• Tomoo Kono
• Yoichiro Taguchi
• Tsurayuki Takahashi
• Naoko Kanemura
• Shoichiro Terada
• Hisao Imai

抄録

背景:

手術ストレスが骨膜に到達すると、骨膜反応として生じる骨吸収や骨形成は、血管新生や血行動態と密接に関連している。そこで我々は、粘膜骨膜フラップ手術後の治癒過程における骨のリモデリングについて、微小循環に着目して検討した。

BACKGROUND: When surgical stress reaches the periosteum, bone resorption and formation that occur as a periosteal response are closely related to angiogenesis and hemodynamics. Thus, we investigated bone remodeling in the healing process after mucoperiosteal flap surgery, focusing our attention on the microcirculation.

方法:

12頭のビーグル成犬を対象に粘膜骨膜フラップ手術を行った。手術後7日目、14日目、21日目、28日目の3つの異なる方法で骨膜血管叢を観察した。

METHODS: Mucoperiosteal flap surgery was performed on 12 adult beagle dogs. The periosteal vascular plexus was observed on days 7, 14, 21, and 28 after surgery, using three different techniques: in histological specimens into which India ink was injected into blood vessels, under a light microscope; in ultrathin sections, using a transmission electron microscope; and in acryl plastic-injected vascular corrosion cast specimens, under a scanning electron microscope.

結果:

術後7日目には、隆起した粘膜血管叢の間質が洞状の新生血管で満たされていた。この新生血管の周囲には破骨細胞による骨吸収が認められ、血管内皮には多数の高透過性フェネストラクションが認められた。術後14日目には、洞状新生血管はより顕著に発達し、一部の部位では骨吸収腔と一致する糸球体様の形態を呈していた。これらの新生血管の周囲には活性化した骨芽細胞が存在し、血管内皮には透過性の高い小胞が認められ、これは小胞-液胞小器官（VVO）やカベオラの可能性があると考えられた。術後21日目と28日目に粘膜血管叢は内皮細胞と線維芽細胞の退縮により解剖され、粗い網目構造に再構築され、同時に骨表面は滑らかになった。

RESULTS: On day 7 after surgery, the interstitum of the elevated mucoperiosteal vascular plexus was filled with sinusoidal new blood vessels. Bone resorption by osteoclasts was observed around these new blood vessels and many highly permeable fenestrations were present in the vascular endothelium. On day 14 after surgery, sinusoidal new blood vessels were more markedly developed and some regions exhibited glomeruluslike morphology consistent with bone resorption cavities. Activated osteoblasts were present around these new blood vessels and highly permeable vesicles, which were considered to be possible vesiclo-vacuolar organelles (VVOs) and caveolae, were noted in the vascular endothelium. On days 21 and 28 after surgery, the mucoperiosteal vascular plexus was dissected through regression of endothelial cells and fibroblasts and reconstructed into a rough mesh structure, and simultaneously the bone surface became smooth.

結論:

骨代謝に伴い粘膜血管叢の形態が変化し、歯周修復に関与する物質の輸送に寄与していることを明らかにした。

CONCLUSION: The morphology of the mucoperiosteal vascular plexus changed with bone metabolism and these changes contributed to transport of substances involved in periodontal repair.

J Periodontol 2005;76:1346-1353.