Citrate synthesis from fatty acids and amino acids in rat ventral prostate.

The source of the remarkably high citrate level of prostate was investigated in prostate fragments. L-Aspartate and alpha-keto-glutarate formed oxaloacetate through transamination. Neither pyruvate nor acetate was as effective as palmitate in increasing the citrate level.

Isocitrate uptake and citrate production by rat ventral prostate fragments.

Prostatic aconitase was investigated utilizing fragments of rat ventral prostate. The rate of citrate formation from isocitrate was used as an index of aconitase activity. Inhibition of citrate formation from isocitrate by fluorocitrate indicated that aconitase activity was being measured.

Citrate and isocitrate utilization by rat ventral prostate mitochondria.

Isolated rat ventral prostate mitochondria preparations were capable of utilizing exogenous isocitrate with some resulting production of citrate. The prostate preparation did not utilize citrate or alphaKG. Citrate utilization via isocitrate seems to be limited by a unique aconitase activity which permits isocitrate to citrate but not citrate to isocitrate conversion.

Citrate uptake and oxidation by fragments of rat ventral prostate.

Citrate oxidation was studied utilizing an in vitro preparation of rat ventral prostate which was very similar, with respect to citrate metabolish, to the intact prostate. The rate of citrate oxidation was very slow in comparison to kidney, although citrate entered prostatic tissue and accumulated intracellularly. Citrate was converted to isocitrate at a rate which resulted in a constant citrate/isocitrate ratio over a 10-fold variation in medium citrate concentration.

RENAL HANDLING OF CITRATE DURING HEAT-INDUCED HYPOCITRICEMIA.

A model of steady-state hypocitricemia, characterized by hypocitraturia and reduced kidney cortex citrate, has been demonstrated in the rate chronically exposed to environmental heat. The renal citrate extraction ratio remains unchanged. The physiological mechanism that brings about the reduction in circulating citrate has not been determined.

Mitochondrial isocitrate dehydrogenase and isocitrate oxidation of rat ventral prostate.

Mitochondrial preparations isolated from rat ventral prostate were capable of oxidizing isocitrate by way of NADP isocitrate dehydrogenase (NADP-IDH) and NAD-IDH. NAD-IDH activity required ADP for activation. The pH responses for NAD-IDH and NADP-IDH were quite different.

Effects of semistarvation on rat liver, kidney, and heart mitochondrial function.

Two groups of rats were provided simultaneously with a commercial stock diet for a period of 7 days. One group was fed ad libitum (control), and the other was restricted to one-fourth of the daily intake of control animals (semistarved). Body weight declined significantly in semistarved rats whereas body weight of controls increased over the 7-day period.