An analysis of the action of lanthanum on aortic tissue from normotensive and spontaneously hypertensive rats Academic Article uri icon

Overview

MeSH Major

  • Aorta, Thoracic
  • Hypertension
  • Lanthanum
  • Vasoconstriction

abstract

  • Significant tension development resulting from the administration of lanthanum salts (La3+) to isolated aorta tissues was observed in preparations from the spontaneously hypertensive rat (SHR) but not in preparation from age-matched normotensive Wistar rats (NWR). The response to La3+ was significantly greater in tissues maintained in bicarbonate-buffered Krebs than observed in bicarbonate and phosphate-free HEPES-buffered Krebs. At least part of the LA3+ response in the bicarbonate- and phosphate-buffered solutions was due to a pH shift and could be mimicked by raising the extracellular hydrogen ion [H+] concentration. However, a direct action of La3+ on excitation-contraction coupling could be observed in HEPES-buffered solutions where the addition of La3+ also resulted in tension development but no significant pH change; this action of La3+ was found to be resistant to inhibition by maintenance in a Ca2+-free medium and (or) D-600 pretreatment suggesting an intracellular action for La3+. The paradoxical response to both H+ and La3+ in the SHR aorta suggests that the muscle membrane may be more permeable to these ions and, in addition, suggests that the membrane and (or) intracellular calcium stores in this tissue may also be more labile than those in the normotensive controls.

publication date

  • December 1977

Research

keywords

  • Academic Article

Identity

Language

  • eng

PubMed ID

  • 21730

Additional Document Info

start page

  • 1084

end page

  • 90

volume

  • 55

number

  • 5