Effects of Acetazolamide and Changes of Acid-Base Balance on the Content of Cyclic Nucleotides in the Rat Kidney

Abstract

Changes in tissue levels of cyclic adenosine 3’:5’-monophosphate (cAMP) and cyclic guanosine 3’:5’-monophosphate (cGMP) in the rat kidney in response to acid-base changes and administration of acetazolamide were measured. cAMP was determined according to the method described by Gilman and cGMP by radioimmunoassay. 1 mg/kg acetazolamide increased bicarbonate excretion 100-fold over the control values to 2.52 ± 0.5 mEq/min (mean ± SEM; n = 6), but did not influence cGMP and cAMP tissue content. 10 and 100 mg/kg acetazolamide increased cGMP tissue levels to 0.277 ± 0.048 and 0.482 ± 0.07 pmol/mg dry weight in comparison to 0.192 ± 0.04 in the controls, whereas no changes in cAMP levels occurred. Chronic as well as acute metabolic alkalosis induced an increase of cGMP levels (0.26 ± 0.03 and 0.29 ± 0.06 pmol/mg), whereas chronic metabolic and acute respiratory acidosis lowered cGMP levels to 0.14 ± 0.02 and 0.13 ± 0.02 pmol/mg. cAMP tissue levels were not affected by changes in acid-base balance. The data could suggest that cGMP participates in the regulation of acid-base balance and renal effects of acetazolamide.

Cerebrospinal fluid production by the choroid plexus: a century of barrier research revisited

“…It has therefore been speculated that the inhibitory action of acetazolamide may affect CSF secretion indirectly by altering choroidal blood flow, cell metabolism, blood pressure, kidney function, plasma [HCO 3 − ] or pCO 2 , etc. [ 169 – 172 ]. However, recent experimental evidence illustrates the acetazolamide lowers ICP in rats by reducing CSF secretion via its inhibitory effect on choroidal carbonic anhydrases [ 167 ].…”