Zone‐specific cell biosynthetic activity in mature bovine articular cartilage: A new method using confocal microscopic stereology and quantitative autoradiography
- 1 May 1996
- journal article
- research article
- Published by Wiley in Journal of Orthopaedic Research
- Vol. 14 (3), 424-432
- https://doi.org/10.1002/jor.1100140313
Abstract
A new methodology was developed to measure spatial variations in chondrocyte/matrix structural parameters and chondrocyte biosynthetic activity in articular cartilage. This technique is based on the use of a laser scanning confocal microscope that can “optically” section chemically fixed, unembedded tissue. The confocal images are used for morphometric measurement of stereologic parameters such as cell density (cells/mm3), cell volume fraction (%), surface density (1/cm), mean cell volume (μm3), and mean cell surface area (μm2). Adjacent pieces of tissue are simultaneously processed for conventional liquid emulsion autoradiography, and a semiautomated grain counting program is used to measure the silver grain density at regions corresponding to the same sites used for structural measurements. An estimate of chondrocyte biosynthetic activity in terms of grains per cell is obtained by dividing the value for grain density by that for cell density. In this paper, the newly developed methodology was applied to characterize the zone-specific behavior of adult articular cartilage in the free-swelling state. Cylinders of young adult bovine articular cartilage were labelled with either [3H]proline or [35S]sulfate, and chondrocyte biosynthesis and structural parameters were measured from the articular surface to the tidemark. The results showed that chondrocytes of the radial zone occupied twice the volume and surface area of the chondrocytes of the superficial zone but were 10 times more synthetically active. This efficient and unbiased technique may prove useful in studying the correlation between mechanically induced changes in cell form and biosynthetic activity within inhomogeneous tissue as well as metabolic changes in cartilage due to ageing and disease.Keywords
This publication has 34 references indexed in Scilit:
- Volume measurements in three‐dimensional microscopyScanning, 1994
- Effect of compressive loading and unloading on the synthesis of total protein, proteoglycan, and fibronectin by canine cartilage explantsJournal of Orthopaedic Research, 1993
- Preservation of cartilage matrix proteoglycans using cationic dyes chemically related to ruthenium hexaammine trichloride.Journal of Histochemistry & Cytochemistry, 1992
- A review of recent advances in stereology for quantifying neural structureJournal of Neurocytology, 1992
- Quantitation of structural features characterizing weight‐ and less‐weight‐bearing regions in articular cartilage: A stereological analysis of medical femoral condyles in young adult rabbitsThe Anatomical Record, 1988
- Some new, simple and efficient stereological methods and their use in pathological research and diagnosisAPMIS, 1988
- Composition and glycosaminoglycan metabolism of articular cartilage from habitually loaded and habitually unloaded sitesArthritis & Rheumatism, 1986
- Sulphate diffusion and incorporation into human articular cartilageBiochimica et Biophysica Acta (BBA) - General Subjects, 1974
- Inter-relationship of articular cartilage thickness and cellularity.Annals Of The Rheumatic Diseases, 1972