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DOI: 10.1055/s-0038-1632293
Drug Effects on Cerebral Blood Flow in the Baboon Model - Acetazolamide and Nimodipine
The authors thank the University of Pretoria for financial support, Davis and Geek division of S.A. Cyanamide for acetazolamide and financial support, and Bayer-Miles (SA) for nimodipine; also the staff of the HA Grové Research Centre who helped with the handling and care of the animals.
Publication History
Received:
05 March 1993
in revised form:
30 July 1993
Publication Date:
03 February 2018 (online)
Summary
The sensitivity of the baboon model under anaesthesia for single photon emission computed tomography (SPECT) of the brain with 99mTc-HMPAO, as recently developed by us to study cerebral blood flow patterns, was investigated using drugs that are known to increase cerebral blood flow, e.g. acetazolamide, the carbonic anhydrase inhibitor and nimodipine, the calcium channel blocker. Increases in cerebral blood flow for both acetazolamide and nimodipine were observed that correspond well with other studies. Statistically significant regional specificity was noted for acetazolamide and nimodipine. Interestingly a combination of these drugs did not enhance cerebral blood flow but rather decreased it in comparison with the individual drug responses. The results were correlated with arterial blood pressure, heart rate, pCO2 and pO2. A blood pressure decrease was noted for both drugs, while acetazolamide had a marked influence on pO2. The results indicate that the baboon model is sensitive for evaluation of drug effects on cerebral blood flow.
Zusammenfassung
Die Empfindlichkeit eines generell narkotisierten Pavian-Modells bei der Untersuchung mit SPECT mit 99mTc-HMPAO, einer kürzlich von uns entwickelten Methode zur Untersuchung der Hirndurchblutung (CBF), wird hier untersucht unter Verwendung von Pharmaka (Acetazolamid, Karboanhydrase- Inhibitor; Nimodipin, Kalziumkanalblocker), von denen bekannt ist, daß sie den humanen CBF steigern. Eine Steigerung des zerebralen Blutflusses wurde sowohl für Acetazolamid als auch für Nimodipin beobachtet, was mit den Ergebnissen anderer Studien gut übereinstimmt. Regionale Spezifität von statistischer Signifikanz wurde für Acetazolamid und Nimodipin festgestellt. Interessanterweise wurde der zerebrale Blutfluß durch eine Kombination der beiden Medikamente nicht verstärkt, sondern, verglichen mit der Wirkung des individuell gegebenen Medikaments, sogar verringert. Die Ergebnisse wurden mit arteriellem Blutdruck, Herzfrequenz, pCO2 und pO2 korreliert. Beide Mittel verringerten den Blutdruck, während Acetazolamid einen deutlichen Einfluß auf pO2 zeigte. Die Ergebnisse machen deutlich, daß das Pavian-Modell unter Narkose empfindlich genug ist, um die Wirksamkeit eines Pharmakons auf den zerebralen Blutfluß zu bewerten.
This work was performed at the H.A. Grové Research Centre
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