ISSN:
1432-2013
Keywords:
Cerebrospinal fluid
;
Blood brain barrier
;
Carbonic anhydrase inhibition
;
Acidosis
;
Alkalosis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract In anaesthetized normocapnic dogs CSF [HCO 3 − ] was increased to ca 33 mmol/l by perfusing the brain ventricles for 45 min with a mock CSF containing a high [HCO 3 − ] which in addition contained 2.5 mg/ml acetazolamide to inhibit central carbonic anhydrase. In dogs with normal plasma [HCO 3 − ], CSF [HCO 3 − ] fell by 5.4 mmol/l in 2 h following the end of the perfusion. Lowering plasma [HCO 3 − ] to 11 mmol/l by infusing HCl intravenously increased the CSF [HCO 3 − ] fall to 7.5 mmol/l. Increasing plasma [HCO 3 − ] to 36 mmol/l completely impeded the fall in CSF [HCO 3 − ]. It is concluded that in these experiments clearing of HCO 3 − from the CSF is critically dependent on plasma [HCO 3 − ]. When the data are compared to those of comparable experiments without intraventricular administration of acetazolamide (Weyne et al. 1982), they indicate that acetazolamide impedes clearing of HCO 3 − from CSF at high and at normal plasma [HCO 3 − ] but not at low plasma [HCO 3 − ]. The experiments therefore suggest a dual contribution for the clearing of HCO 3 − from the CSF after its experimental increase: diffusion along the CSF-plasma gradient for HCO 3 − and a carbonic anhydrase dependent clearing of HCO 3 − .
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00584700
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