Divergent action of verapamil perfused in two hypothalamic areas on body temperature of the cat.

Published

Journal Article

Guide cannulae for push-pull perfusion were bilaterally implanted stereotaxically within the anterior hypothalamic, preoptic area (AH/POA) and posterior hypothalamus (PH) of the cat. Catecholamine-reactive sites were identified within AH/POA in which a microinjection of norepinephrine (NE) (5.0 micrograms) evoked a characteristic, transient hypothermia. Similarly the cation-reactive region within the PH was identified in which excess Ca2+ (25 mM) also evoked a hypothermic response. When verapamil was perfused at a rate of 25.0 microliters/min in a concentration of 0.4 or 2.0 micrograms/microliter within AH/POA at a NE-sensitive site, a concentration-dependent decline in the core temperature of the cat occurred. Conversely, verapamil perfused in the same manner with a Ca2+-reactive site caused an intense rise in the cat's body temperature which also was concentration dependent. These results show that the localized blockade of slow Ca2+ channels exerts direct, differential physiological effects within central nervous system tissue. In this case, verapamil mimics noradrenergic effects within the AH/POA; however, the hyperthermic response following Ca2+ channel blockade within tissue of the PH resembled that produced by ethyleneglycoltetraacetic acid or Na ions.

Full Text

Duke Authors

Cited Authors

  • Beleslin, DB; Rezvani, AH; Myers, RD

Published Date

  • June 24, 1985

Published In

Volume / Issue

  • 57 / 3

Start / End Page

  • 307 - 312

PubMed ID

  • 4034099

Pubmed Central ID

  • 4034099

International Standard Serial Number (ISSN)

  • 0304-3940

Digital Object Identifier (DOI)

  • 10.1016/0304-3940(85)90510-5

Language

  • eng

Conference Location

  • Ireland