Water-soluble factors with vitamin K activity from pig liver and from Fusiformis nigrescens

Relaxation of arterial smooth muscle: a new function of a water-soluble degradation product of coenzyme Q (ubiquinone)

Treatment of coenzyme Q with ozone yielded a degradation product having unmodified ring that retained its spectral characteristics and a truncated side-chain that made it water-soluble. This derivative, but not the intact lipid-quinone, showed relaxation of phenylephrine-contracted rat arterial rings. This effect offers an explanation for the known hypotensive action of exogenous coenzyme Q regardless of its side-chain length.

Vitamin K deficiency in Fusiformis nigrescens. I. Influence on whole cells and cell envelope characteristics

Vitamin K depletion in the vitamin K-requiring anaerobe Fusiformis nigrescens resulted in the formation of elongated cells. In the presence of vitamin K, inhibition by cyanide and heme depletion did not affect cell morphology. Peptide depletion, as well as inhibition by chloramphenicol, ethionine, or fluorophenylalanine, also resulted in formation of elongated cells. Chemical analysis of cells and envelopes showed that protein, lipid, and deoxyribonucleic acid levels were similar in vitamin-supplemented and depleted cells; however, ribonucleic acid (RNA) levels in depleted cells and envelopes were significantly higher than in K-supplemented cells. Sections of cells of both groups showed minor differences in cell surfaces. The relationship between altered cell envelopes and increased RNA levels in K-deficient bacteria indicated a membrane-mediated effect of vitamin K on RNA and possibly protein synthesis in this microorganism.