Possible Interaction: Alpha-Ketoglutarate and Calcium Supplement

“In the lactating sows, dietary supplementation of AKG decreased plasma urea level on d 14 of lactation, decreased plasma calcium ( Ca ) concentrations from d 7 to d 21 of lactation and increased lactose and Ca levels in ordinary milk.”

“Thus, it was proposed that AKG supplementation stimulates the capacity for lactose synthesis and Ca uptake in the mammary gland, thereby altering the composition of the ordinary milk which might be associated with the enhanced performance of piglets during the suckling period.”

“The Ca2+ -induced increments of state 3 respiration decrease with substrate in the order glutamate> α-oxoglutarate >isocitrate>α-glycerophosphate>pyruvate.”

“With the KC1-medium and with alpha-ketoglutarate as the respiratory substrate, state 3 respiration but not state 4 respiration was inhibited by calcium.”

“Increasing calcium concentration in the incubation medium inhibited 14CO2 production from 14C-labeled alpha-ketoglutarate and succinate, stimulated 14CO2 production from [1-14C]glucose and [1-14C]glutamate, but was without effect on that from [6-14C]glucose.”

“ Ca2+ (maintained at 10 muM by a Ca2+ buffer) decreased the S0.5 for alpha-ketoglutarate 63-fold (from 25 to 0.40 mM); even in the presence of a positive effector, ADP or phosphate, Ca2+ decreased the S0.5 for alpha-ketoglutarate 7.8- or 28-fold, respectively.”

“Consistent with a mechanism of action dependent of Ca2+, …) or phosphate (20 mM) reduced the S0.5 for alpha-ketoglutarate … Ca2+ ( i.e., 4.5- or 1.67-fold, respectively); however, these effectors elicited larger decreases … in the absence of Ca2+ (i.e., 37- or 3.7-fold, respectively).”

“ Ca2+ ( and Sr2+) diminished the Km for the oxidation of both threo-Ds-isocitrate and oxoglutarate.”

“ Calcium ions affected mitochondrial function causing reduced oxidation of oxoglutarate , elimination of pyruvate oxidation and a decline in respiratory control of these substrates with increased oxidation of NADH and NADPH.”

“In Ca2+-induced cells oxoglutarate dehydrogenase activity was deleted within 6.5 h of Ca2+ addition and this was accompanied by establishment of an ‘incomplete Krebs cycle’.”