title: Aconitase activity, citrate oxidation, and zinc inhibition in rat ventral prostate.
abstract: Aconitase activity and citrate oxidation were determined in mitochondrial preparations from rat ventral prostate. Aconitase activity in prostate mitochondria was approximately 10% of the activity observed in kidney preparations. The prostate aconitase activity was completely inhibited by the addition of 1.0 mmol/l zinc and kidney aconitase was inhibited by approximately 50%. The presence of 1.0 mmol/l zinc also markedly inhibited the formation of isocitrate from cis-aconitate. The reduction of NADP by citrate was markedly inhibited (approx. 95%) by 1.0 mmol/l zinc as compared with a 70 and 40% inhibition of aconitate--and isocitrate--stimulated reduction, respectively. These results indicate that zinc might be a strong inhibitor of aconitase activity with an inhibitory effect on isocitrate dehydrogenase also. The effect of 1.0 mmol/l zinc on citrate oxidation was studied by determining 14CO2 production from 6-14C-citrate. 14CO2 was significantly inhibited by zinc. These results further corroborate the conclusion that citrate accumulation in prostate might be the result of limited citrate oxidation which results from a combination of low aconitase activity and possibly zinc inhibition.
mesh_terms: D000154:Aconitate Hydratase / Q000037:antagonists & inhibitors*; D000818:Animals; D002951:Citrates / Q000378:metabolism*; D019343:Citric Acid; D007668:Kidney / Q000201:enzymology; D008297:Male; D008928:Mitochondria / Q000201:enzymology; D010084:Oxidation-Reduction / Q000187:drug effects; D011467:Prostate / Q000201:enzymology*; D051381:Rats; D015032:Zinc / Q000494:pharmacology*
chemical_list: D002951:Citrates; D019343:Citric Acid; D000154:Aconitate Hydratase; D015032:Zinc