Ion Association. Iii. The Effect of Sulfate Infusion on Calcium Excretion *†

Ion Association. Iv. Effect of Sodium Sulfate Infusion on Renal Clearance and Body Retention of Injected Radiostrontium in Dogs*

“…Despite considerable variation in the size of the dogs and in the interval between isotope administration and start of therapy (see Table I), a uniform relationship is observed, which appears to be linear. This relationship resembles that found between calcium clearance and sulfate excretion in dogs, reported previously (34). A similar linear relationship is seen when radiostrontium clearance is plotted against plasma sulfate concentration.…”

“…During the clearance measurements, urine was collected by indwelling urethral catheters, and each sample was analyzed separately. The technique of the clearance experiments and methods of analysis of calcium, creatinine and sulfate are described elsewhere (34,40,41). Stool samples were homogenized with water in a blender.…”

“…In the first two blood samples, after starting the infusion of sulfate, plasma calcium is low due to omission of this ion from the infusion (34). Nevertheless, the strontium clearances in these periods are 45 and 42 ml per 100 ml GF.…”

“…The marked effect of sulfate infusion on the renal excretion of both calcium and magnesium (33,34) suggested the use of sodium sulfate in order to accelerate strontium excretion. The mechanism by which sulfate augments the excretion of alkaline earth cations, discussed in a previous paper (34), is apparently related to the formation of electrostatic ion-pairs, which differ from metalchelate compounds in that covalent bonding is not thought to occur (35).…”

“…The mechanism by which sulfate augments the excretion of alkaline earth cations, discussed in a previous paper (34), is apparently related to the formation of electrostatic ion-pairs, which differ from metalchelate compounds in that covalent bonding is not thought to occur (35). Although the dissociation constant of the strontium sulfate ion-pair has apparently not been reported, it is probably close to the dissociation constants of the calcium sulfate and magnesium sulfate ion-pairs, both of which are approximately 0.06 M at ionic strength 0.…”