Bone canaliculus endings in the area of the osteocyte lacuna

Pawlicki, R

doi:10.1159/000144391

Cited by 10 publications

(6 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The morphology of the processes elaborated by osteoblastslnascent osteocytes revealed by this study extend the observations of Cooper et al (1966), Baud (1968, and Pawlicki (1974, 1975. Each of those laboratories had already described processes extending from hillocklike expansions of the cell surface that bifurcate before passing into bone matrix, and that these processes can send off small caliber lateral branches.…”

Section: Discussionsupporting

confidence: 88%

“…Each of those laboratories had already described processes extending from hillocklike expansions of the cell surface that bifurcate before passing into bone matrix, and that these processes can send off small caliber lateral branches. Pawlicki (1974Pawlicki ( , 1975 called these expansions "funnel like" or "Type 1 junctions," as opposed to the simple branchings, or "Type 2 junctions," and also described branches of canaliculi which took a rather circular course around collagen fibers. There have been no reports, heretofore, that cell processes could terminate on the cell bodies of osteocytes, and these were not apparent in recently published SEMs of osteocyte-cell process plexi exposed after substantial bone matrix had been removed by exhaustive extraction with 0.6N HC1 and collagenase (Ejiri and Ozawa, 1982;Johnson and Highison, 1983).…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

From bone lining cell to osteocyte—an SEM study

et al. 1984

View full text Add to dashboard Cite

We describe the SEM appearance of the rat endosteal bone lining cell ( BLC ) population, and the sequence of morphological changes of these cells as they self-incorporate into unmineralized bone matrix (osteoid), establish intercellular connections, and construct lacunae. The osteoblast/nascent osteocyte series was progressively unsheathed by gentle digestion of the osteoid with 0.25% collagenase. The osteoblasts which leave the polygonally packed BLC compartment rapidly develop numerous complexly branched processes that contact the processes elaborated by previous generations of maturing and mature osteocytes. As osteoblasts mature and approach the mineralization front, they appear to lose processes. The mature cells begin to form osteocyte lacunae by depositing an asymmetric perimeter of woven collagen fibrils, such that as the cells roof-over, the lacunae appear as pocketlike constructions. The collagen fibrils on the perilacunar matrix are oriented in a tangential or circular pattern, while those in the more distal matrix are arranged in a parallel pattern. With the completion of a lacuna, its wall appears to mineralize quickly, for lacunae could be recognized only when they are forming.

show abstract

Section: Discussionsupporting

confidence: 88%

Section: Discussionmentioning

confidence: 99%

From bone lining cell to osteocyte—an SEM study

et al. 1984

View full text Add to dashboard Cite

show abstract

“…That the osteocyte/dendrite network surface is wet by interstitial fluid is an ascertained fact and membrane transport mechanisms can convey metabolites into the cells (Shapiro, 1988;Kusuzaki et al, 2000). Connections between bone cells through gap junctions were documented with transmission electron microscopy and atomic force microscopy (Weiniger & Holtrop, 1974;Pawlicki, 1975;Stanka, 1975;Doty, 1981;Larsen, 1983). The osteocyte processes stay in the centre of the canalicula, with a gap between the cellular membrane and the canalicular wall (You et al, 2004): this suggests that extracellular fluid can pass through the system in an intracanalicular but extracellular/extra-processes position (Doty, 1981;Shapiro, 1988).…”

Section: Discussionmentioning

confidence: 99%

The cast imaging of the osteon lacunar‐canalicular system and the implications with functional models of intracanalicular flow

Pazzaglia

Congiu

2012

Journal of Anatomy

View full text Add to dashboard Cite

A casting technique with methyl-methacrylate (MMA) was applied to the study of the osteon lacunarcanalicular network of human and rabbit cortical bone. The MMA monomer infiltration inside the vascular canals and from these into the lacunar-canalicular system was driven by capillarity, helped by evaporation and the resulting negative pressure in a system of small pipes. There was uniform, centrifugal penetration of the resin inside some osteons, but this was limited to a depth of four to five layers of lacunae. Moreover, not all of the osteon population was infiltrated. This failure can be the result of one of two factors: the incomplete removal of organic debris from the canal and canalicular systems, and lack of drainage at the osteon external border. These data suggest that each secondary osteon is a closed system with a peripheral barrier (represented by the reversal line). As the resin advances into the osteon, the air contained inside the canalicula is compressed and its pressure increases until infiltration is stopped. The casts gave a reliable visualization of the lacunar shape, position and connections between the lacunae without the need for manipulations such as cutting or sawing. Two systems of canalicula could be distinguished, the equatorial, which connected the lacunae (therefore the osteocytes) lying on the same concentric level, and the radial, which established connections between different levels. The equatorial canalicula radiated from the lacunar border forming ramifications on a planar surface around the lacuna, whereas the radial canalicula had a predominantly straight direction perpendicular to the equatorial plane. The mean length of the radial canalicula was 40.12 ± 10.26 lm in rabbits and 38.4 ± 7.35 lm in human osteons; their mean diameter was 174.4 ± 71.12 nm and 195.7 ± 79.58 nm, respectively. The mean equatorial canalicula diameter was 237 ± 66.04 nm in rabbit and 249.7 ± 73.78 nm in human bones, both significantly larger (P < 0.001) than the radial. There were no significant differences between the two species. The lacunar surface measured on the equatorial plane was higher in rabbit than in man, but the difference was not statistically significant. The cast of the lacunarcanalicular network obtained with the reported technique allows a direct, 3-D representation of the system architecture and illustrates how the connections between osteocytes are organized. The comparison with models derived by the assumption of the role of hydraulic conductance and other mechanistic functions provides descriptive, morphological data to the ongoing discussion on the Haversian system biology.

show abstract

“…This suggests a different function existing for each; namely, collagen fibril orientation for the large and flat foldings of the membrane and interconnections between osteocytes for the thin filaments (Weinger and Holtrop 1974;Pawlicki 1975;Stanka 1975;Doty 1981;Shapiro 1988). It is these thin filaments which are oriented in a radial direction with respect to the vascular axis of the osteon.…”

Section: Discussionmentioning

confidence: 99%

The shape modulation of osteoblast–osteocyte transformation and its correlation with the fibrillar organization in secondary osteons

et al. 2010

View full text Add to dashboard Cite

Cortex fractured surface and graded osmic maceration techniques were used to study the secretory activity of osteoblasts, the transformation of osteoblast to osteocytes, and the structural organization of the matrix around the cells with scanning electron microscopy (SEM). A specialized membrane differentiation at the base of the cell was observed with finger-like, flattened processes which formed a diffuse meshwork. These findings suggested that this membrane differentiation below the cells had not only functioned in transporting collagen through the membrane but also in orienting the fibrils once assembled. Thin ramifications arose from the large and flat membrane foldings oriented perpendicular to the plane of the osteoblasts. This meshwork of fine filaments could not be visualized with SEM because they were obscured within the matrix substance. Their 3-D structure, however, should be similar to the canalicular system. The meshwork of large, flattened processes was no more evident in the cells which had completed their transformation into osteocytes.

show abstract

Bone canaliculus endings in the area of the osteocyte lacuna

Cited by 10 publications

References 2 publications

From bone lining cell to osteocyte—an SEM study

From bone lining cell to osteocyte—an SEM study

The cast imaging of the osteon lacunar‐canalicular system and the implications with functional models of intracanalicular flow

The shape modulation of osteoblast–osteocyte transformation and its correlation with the fibrillar organization in secondary osteons

Contact Info

Product

Resources

About