Effect of progressive decrease of oxygen tensions on rat articular chondrocytes: a Light and scanning electron microscopy study

Fareed Alfaya Asiri¹, Sobhy Hassan Aly Ewis², Mohamed Samir Ahmed Zaki²*, Refaat A. Eid³ and Sherieif El-Sayed Abd El-Farrag Ibrahim⁴

¹Department of Orthopedic Surgery, King Khalid University, College of Medicine, Saudi

²Department of Anatomy, King Khalid University, College of Medicine, Saudi

³Department of Pathology, King Khalid University, College of Medicine, Saudi

⁴Department of Physiotherapy (Physical medicine), Mansoura University, College of Medicine, Egypt

*Corresponding Author E-mail: mszaki1@hotmail.com 

Accepted 29 January, 2014

Abstract

Oxygen is a critical parameter proposed to modulate the functions and structures of chondrocytes. Articular cartilage is comprised of chondrocytes surrounded by a dense extracellular matrix. Collagen forms the structural skeleton of the tissue. At the onset of cartilage degeneration, due to surface fibrillation, such gradients have been proposed to break down, thus contributing to the progression of the disease. This article investigates the effect of low oxygen percentage at different periods on the rat articular chondrocytes at at the histological level. Forty healthy young male albino rats were used in this study and divided into four groups. The control group admitted in normal environment at sea level rates. The second, third and fourth groups admitted in high altitude environment above sea level for ten days, twenty days and thirty days respectively. At the end of the previous mentioned periods the rats were anesthetized and the knee joint dissected and the menisci were taken and prepared using hematoxylin and eosin (H and E), Masson’s trichrome stains for light microscopy and prepared also for scanning electron microscopy (SEM) examination. On progression of low oxygen tension, by H and E stain highly destructed chondrocytes, pyknotic nuclei, no clear lacunae and shrunken cytoplasm were observed and by Masson’s trichrome stain more concentrations of collagenous fibers that are destructed and on SEM examination chondrocytes showed disintegration of chondrocytes with disrupted microvilli on their surface with elevations containing aligned hydroxyapatite crystallitesand destructed collagen fibrils were observed. Low oxygen tensions could modulate the chondrocytes and collagen fibrils and promote its extracellular matrix production.

Keywords: Varying Oxygen Tensions, Rat articular Chondrocytes, Light and Scanning Electron Microscopy