Polarized Distribution of Organelles in Paired Chondrocytes from the Superficial Zoneof Lapine Articular Cartilage

Introduction: Cells in tensile-bearing soft connective tissues rarely, if ever, exist in isolation. Rather, they are interconnected via cytoplasmfilled cytoplasmic processes and gap junctions [1, 2]. These gap junctions contain connexin 43, a member of the connexin family of gap junction proteins whose expression in connective tissues can be influenced by mechanical loads [1]. In contrast, chondrocytes in the cartilage of various animal species can be found in lacunae, have a round morphology, and show no physical linkages. Interestingly, chondrocytes express connexin 43 [3], and retain the capacity to form functional gap junctions after isolation and monolayer culture [3]. To clarify the relationship between neighboring chondrocytes and the role of connexin 43, we examined the distribution of chrondrocytes in the superficial layer of the rabbit femoral condyle using both indirect immunofluorescent confocal and electron microscopy and compared that with the distribution of connexin 43.