The regional localization of R28935 in the cat brain as dependent on the route of administration

A.J.M. Loonen, W. Soudijn, H.H. Van Rooij, I. Van Wijngaarden

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Intravenous injection of the antihypertensive agent R28935 and its pharmacologically less active threo-isomer R29814 resulted in a distribution profile in the cat brain which differed from the regional localization after administration via the left vertebral artery. Although the 2 isomers had the same physicochemical properties, R28935 penetrated more readily into the CNS. Intravenous administration resulted in almost equal levels in all brain parts, whereas after injection into the vertebral artery caudal structures contained more of both compounds than rostral structures. Differences existed between the concentrations in homotopic brain areas, especially in the brain stem. From comparison of the levels of R28935 after injection of an equiactive dose either i.v. or into the vertebral artery it is tempting to speculate that the mesencephalic tegmentum, the nucleus of the solitary tract, the inferior colliculi and/or the locus coeruleus are possible sites of the hypotensive action.
Original languageEnglish
Pages (from-to)281-285
Number of pages5
JournalNaunyn-Schmiedeberg's Archives of Pharmacology
Issue number3
Publication statusPublished - 22-Apr-1979
Externally publishedYes


  • 1 [1 [2 (1,4 benzodioxan 2 yl) 2 hydroxyethyl] 4 piperidyl] 2 benzimidazolinone
  • radioisotope
  • unclassified drug
  • animal experiment
  • article
  • bacillus ceruleus
  • brain
  • cat
  • central nervous system
  • drug distribution
  • inferior colliculus
  • intraarterial drug administration
  • intravenous drug administration
  • solitary tract nucleus
  • stereospecificity

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