Relaxation of arterial smooth muscle by water-soluble derivatives of coenzyme Q (ubiquinone).

Treatment of coenzyme Q with ozone, permanganate, and ferrous sulfate in presence of ascorbate or hydrogen peroxide yielded water-soluble degradation products, possibly having truncated side-chain and modified ring.These derivatives, but not the intact lipid-quinone, showed relaxation of phenylephrine-contracted rat arterial rings. Representative samples of these also decreased blood pressure when injected into the femoral vein in the rat.These effects offer an explanation for the hypotensive action of exogenous coenzyme Q regardless of its side-chain length.