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WE show here, from an analysis of geological observations in the Phlegraean Fields, that the high correlation among slow ground motions, seismicity and short and long period tidal components (including the Chandler wobble) observed at Pozzuoli (Naples) suggests that the sea, throughout intercrustal hydrodynamic correlation, may be an important geodynamic agent.

CONTINUING the chromatographic work carried out on tryptophan–nicotinic acid metabolism on urine of mice affected with experimental MHV-3 virus1, we have investigated the effect of viral hepatitis on the relationship between tryptophan and nicotinic acid in man.

IN recent studies in vivo and in vitro, we have shown that the K vitamins (K1, K2, phthiocol, menadione and ‘Synkavit’) inhibit the synthesis of nicotinic acid at the stage 3-hydroxyanthranilic acid→quinolinic acid. We suggested that the mechanism of inhibition is competition between vitamin K and 3-hydroxyanthranilic acid, that is, the K vitamins exert antimetabolitic action on the substrate of the reaction catalysed by 3-hydroxyanthranilic acid oxidase. On the basis of this hypothesis, investigations were undertaken to determine if the inhibition of 3-hydroxyanthranilic acid oxidase produced in vivo by administration of menadione or ‘Synkavit’ could be reversed by subsequent administration of 3-hydroxyanthranilic acid. The results of these experiments demonstrated the capacity of 3-hydroxyanthranilic acid to overcome the inhibitory effect of vitamin K.

THE reactions reported here are considered to be the final steps in the chain of reactions whereby tryptophan is converted into vitamin1; it shows the inhibitory action of the carcinogenic substance 2-acetylaminofluorene on the reaction 3-hydroxy-anthranilic acid→quinolinic acid.

THE existence of biochemical lesions in the complicated path from amino-acid to vitamin in man, and in experimental animals suffering from various diseases, has been identified by a number of authors analysing urinary metabolites of tryptophan by means of paper and column chromatography1–6. These analyses have shown an accumulation in the urine of metabolites proximal to the lesion.

DUNNING et al. 1 demonstrated that bladder cancer due to 2-acetylaminofluorene was produced in almost all rats (strain Fisher 344) on a diet containing large quantities (1.4–4.3 per cent) of tryptophan. On the other hand, rats on a diet containing smaller amounts of tryptophan did not develop bladder cancer. We showed that the administration of 2-acetylaminofluorene inhibits 3-hydroxyanthranilic acid oxidase in rat hepatic tissue2, with consequent accumulation of the two carcinogenic o-aminophenolic compounds 3-hydroxyanthranilic acid and 3-hydroxy-kynurenine3. It seemed of interest to pursue these studies in order to elucidate the mechanism of this inhibition.