Effect of acetazolamide on renal metabolism and ammoniagenesis in the dog.

The effect of acetazolamide (ACZ) on renal metabolism and ammoniagenesis was studied in the dog in vivo and in vitro. ACZ was administered to 10 dogs with normal acid-base status and five with chronic metabolic acidosis induced by NH4Cl. In both groups of dogs, the acute administration of ACZ markedly reduced the urinary excretion of ammonium (from 33 to 10 in normal dogs and from 100 to 23 mumoles/100 ml GFR in acidotic dogs) whereas its release into the renal vein was increased in a reciprocal fashion (from 69 to 95 in normal dogs and from 91 to 152 mumoles/100 ml GFR in acidotic dogs).

Enzymic assay for serum theophylline.

We describe an original procedure for determination of theophylline in serum. The drug is extracted from 0.4 mL of serum at pH 7.

Improved determination of serum theophylline by gas chromatography with use of a nitrogen-phosphorus detector.

We describe a method for the 7-min determination of theophylline in less than 100 muL of serum. The procedure requires no centrifugation or solvent evaporation after extraction. Butylation is done on the gas-chromatographic column by injecting the serum extract followed by a butylating mixture which contains 1-iodobutane as the alkylating agent.