Abstract
It was elucidated that sodium monofluoroacetate (SFA) condensed with oxaloacetate and converted to fluorocitrate which ‘jams’ the tricarboxylic acid cycle by inhibiting the aconitase. Citrate also accumulates in tissues of animals poisoned with SFA. However, the livers of normal female rats accumulated the large quantities of citric acid in contrast to the inability of normal male rats to accumulate citrate in the liver. Further, following castration female rats did not decrease citrate synthesis in the liver but castrated and adrenalectomized male rats acquired the ability to accumulate citric acid in the liver after SFA treatment. By the above facts, an inhibition of citrate synthesis by sex hormones might be responsible for this sex difference. The present investigation was undertaken to obtain further information on the influence of various hormones on citrate synthesis by liver and kidneys.
1. No sex difference was observed in the accumulation of citrate in the normal liver and kidneys of rats.
2. Following SFA treatment, the livers of normal female rats accumulate the large quantities of citric acid in contrast to the inability of normal male rats to accumulate citrate in the liver.
3. Castration of female rats decrease the ability of the liver to accumulate citrate following SFA treatment wheras male rats acquired the ability to accumulate citrate in the liver following castration.
4. Administration of testoterone to normal male and female rats for several days decreased citrate synthesis in the liver. However, the administration of estradiole induced the increase in amount of liver citrate not only in the male, but even further increase in the female. This facts suggests that estrogen acts promotingly to the liver citrate synthesis.
5. After administration of excess amount of progesterone to castrated female rat, inhibition of liver citrate synthesis was observed.
6. Following administration of the solution of desiccated thyroid gland powder to normal male rat, accumulation of liver citrate was observed. However, with castrated female rat, only in 1 out of 5 cases, an eminent accumulation was observed. After castrated male rat was treated with thiouracil and supression of androgen and thyroxine might be obtained, the accumulation of liver citrate was as low as in the case of nomal male rat treated SFA.
7. Following administration of cortisone acetate to castrated male rats, accumulation of citrate was observed in 3 out of 5. However, in castrated female rat livers, cortison acetate inhibits citric acid synthesis.
