PubMed Health⌕ Search

Biomedical subjects

J Astrup

Publications and source records attributed to J Astrup.

At least 91 records · Page 5Linked to original sources
PubMed1977

EEG and extracelluar K+ in rat brain during pentylenetetrazol seizures and during respiratory arrest.

The relationship between changes in EEG and the extracellular potassium concentration (K+e) in brain cortex was studied in rats during petylenetetrazol seizures and during respiratory arrest. During seizures an increase of K+e occurred subsequent to the electrical discharges, while during postictal depression of EEG normal levels of K+e were measured. During respiratory arrest K+e rose considerably one minute after flattering of EEG. These findings are against a concept of K+e determining the changes of the EEG pattern. It is hypothetized that during seizures the increased K+e may play an important role in the coupling of neuronal activity to cerebral blood flow and metabolism.

Animals↗
PubMed1975

Brain carbonic acid acidosis after acetazolamide.

In cats in barbiturate anesthesia extracellular pH and potassium were continously recorded from brian cortex by implanted microelectrodes. Implantation of the electrodes preserved the low permeability of the blood-brain-barrier to HCO3-minus and H+ions as indicated by the development of brain acidosis by I.V. injection of HCO3-minus. Acetazolamide (25 mg/kg) i.v. was followed by a marked brain acidosis which after 10 min had progressed to a drop in pH of 0.203 plus or minus 0.046 (x bar plus or minus S.D., n equals 8). The slowness ofthe development of acidosis points to a direct effect of the carbonic anhydrase inhibition on the brain tissue. As a further support for this conclusion was considered the finding of a prolonged response time of brain pH to HCO3-minus i.v. to CO2-minus inhalation, and to hyperventilation after the acetazolamide inhibtion. No changes in brain extracelllular potassium were found.

Acetazolamide↗