Evidence of a pure "contraction alkalosis= in awaken rat.

A pure contraction alkalosis with no urinary loss of bicarbonate was evidenced in awaken rat, after a Furosemide IV injection. We observed: 1) an early and important respiratory compensation possibly owing to a simultaneous contraction of CSF volume, thus increasing bicarbonate concentration. 2) a net shift of HCO3- towards intracellular compartment, in proportion to the magnitude of the contraction rather than to bicarbonate gradient across the membrane.