Changes in calcium-dependent membrane permeability properties in mitochondria of livers from arthritic rats

✍ Scribed by Pamelli Maria de Souza Silva; Eduardo Tanabe; Aparecida Pinto Munhos Hermoso; Ciomar A. Bersani-Amado; Adelar Bracht; Emy L. Ishii-Iwamoto; Clairce Luzia Salgueiro-Pagadigorria

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 109 KB
• Volume: 26
• Category: Article
• ISSN: 0263-6484
• DOI: 10.1002/cbf.1461

✦ Synopsis

Abstract

The involvement of the mitochondrial permeability transition pore (PTP) in the responses of mitochondria from adjuvant‐induced arthritic rats to Ca^2+^ addition was investigated. The respiratory activity, the Ca^2+^‐induced osmotic swelling and the electrophoretic ^45^Ca^2+^ uptake were evaluated in the absence and in the presence of cyclosporin A (CsA), a well‐known inhibitor of the mitochondrial PTP. The Ca^2+^‐induced mitochondrial permeability transition (MPT) process occurred in mitochondria from arthritic rats even in the presence of a low Ca^2+^ concentration. Whereas in the normal condition, the Ca^2+^‐induced uncoupling of oxidative phosphorylation and osmotic swelling was observed in the presence of 10 or 20 µM Ca^2+^ concentration, in the arthritic condition, these events occurred at 1.0 µM concentration. In addition, mitochondria from arthritic rats presented an impaired ability to accumulate ^45^Ca^2+^. All these effects were completely prevented by the administration of CsA. The results of the present study suggest that the higher sensitivity of mitochondria from arthritic rats to Ca^2+^‐induced MPT may be an important factor in the pathogenesis of the arthritis disease. Copyright © 2008 John Wiley & Sons, Ltd.