The stability constants of the alkaline earth lactate and α-hydroxyisobutyrate complexes

Effects on Ionized Calcium of a Correction of Acidosis With Alkalinizing Agents

“…ionized caldum in lactic addosis as compared with hypercapnic or hydrochloric addosis is attributed to the formation of caldum-lactate complexes (Verbeek and Thun, 1965;Schaer and Bachmann, 1974). The data presented confirm the hypothesis that the correction of lactic addosis with alkalinizing agents will restore the pH to normal while redudng ionized caldum to less than control values.…”

“…A shift in pH from 7.4 to 6.9 units increases ionized calcium by 0.23-0.40 m mol in hypercapnic acidosis (Hinkle and Cooperman, 1971;Hoffken et al, 1971;Pedersen, 1971;Schaer and Bachmann, 1974), whereas an identical pH shift in lactic acidosis increases ionized calcium by only 0.14 m mol (Schaer and Bachmann, 1974). This difference in ionized calcium is explained fully by the formation of calcium lactate complexes (Verbeek and Thun, 1965;Schaer and Bachmann, 1974). It has been suggested that this differential behaviour of ionized calcium in respiratory and lactic acidosis contributes to the differences in the cardiovascular effect of these two forms of acidosis in intact animals or humans (ligou and Nahas, 1960;Carson et al, 1965;Schaer and Bachmann, 1974).…”

Ionized Calcium in Acidosis: Differential Effect of Hypercapnic and Lactic Acidosis

“…It can be seen that our experimental points correspond closely with pH values read from the nomogram. The stability constants for the calcium-lactate (CaL) complexes have been determined (Verbeek and Thun, 1965). These authors found stability constants 1^ = 8.0 litre/mol (log /?,=0.90±0.01) for the CaL+ complex, and K a = 17.4 litre/mol (log #,= 1.24 ±0.015) for the CaL 3 complex.…”

Complex formation between calcium and hydroxy/oxocarboxylates in neutral and highly alkaline aqueous solutions

“…In neutral or acidic solutions containing both Ca 2+ and Lac -, the formation of the CaLac + complex has been detected with the formation constant, logβ1,1 ranging between 0.48 and 1.47 (values measured at the 0-1 M ionic strength range). [22,23,30,53,54,[56][57][58] In two papers, however, the formation of the charge neutral CaLac2 0 complex was also reported. [53,54] In these works, the formation constants of the two complexes were determined to be logβ1,1 = 0.90, logβ1,2 = 1.24 at I = 1.0 M [53] and logβ1,1 = 0.92, logβ1,2 = 1.62 at I = 0.5 M. [54] The binding sites of Lacin the CaLac + complex have also been determined by 13 C NMR spectroscopic measurements.…”

“…[22,23,30,53,54,[56][57][58] In two papers, however, the formation of the charge neutral CaLac2 0 complex was also reported. [53,54] In these works, the formation constants of the two complexes were determined to be logβ1,1 = 0.90, logβ1,2 = 1.24 at I = 1.0 M [53] and logβ1,1 = 0.92, logβ1,2 = 1.62 at I = 0.5 M. [54] The binding sites of Lacin the CaLac + complex have also been determined by 13 C NMR spectroscopic measurements. Lacwas found to act as a bidentate ligand binding Ca 2+ through both the carboxylate and the hydroxyl groups.…”