INORGANIC SULFATE-INDUCED SWELLING IN ISOLATEDD RAT-LIVER MITOCHONDRIA

Inorganic sulfate induced a large-amplitude swelling in isolated rat-liver mitochondria. Compared with the phosphate-induced swelling, the sulfate-induced swelling was less extensive. Succinate and α-ketoglutarate delayed initiation of the swelling, but increased its extent in the later phase. Bovine serum albumin, EDTA, inhibitors of the respiratory chain and 2, 4-dinitrophenol, but not oligomycin, prevented the swelling induced by sulfate. The sulfate-induced swelling, which was accompanied by a slight increase in a latent ATPase [EC 3.6. 1.3], was reverted by ATP plus Mg+-. From experiments using respiratory-chain inhibitors, and artificial electron donors and acceptors, it was concluded that the sulfate-induced swelling was supported by a high energy intermediate of any one of the three energy-conservation sites in the respiratory chain. © 1969 BY THE JOURNAL OF BIOCHEMISTRY.