Temperature sensitivity of catecholamine secretion and ion fluxes in bovine adrenal chromaffin cells

Mol Cells. 1999 Feb 28;9(1):67-71.

Abstract

The effects of temperature on ion fluxes and catecholamine secretion that are mediated by nicotinic acetylcholine receptors (nAChRs), voltage-sensitive calcium channels (VSCCs), and voltage-sensitive sodium channels (VSSCs) were investigated using bovine adrenal chromaffin cells. When the chromaffin cells were stimulated with DMPP, a nicotinic cholinergic agonist, or 50 mM K+, the intracellular calcium ([Ca2+]i) elevation reached a peak and decreased more slowly at lower temperatures. The DMPP-induced responses were more sensitive to temperature changes compared to high K+-induced ones. In the measurement of intracellular sodium concentrations ([Na+]i), it was found that nicotinic stimulation required a longer time to attain the maximal level of [Na+]i at lower temperatures. In addition, the VSSCs-mediated [Na+]i increase evoked by veratridine was also reduced as the temperature decreased. The measurement of [3H]norepinephrine (NE) secretion showed that the secretion within the first 3 min evoked by DMPP or high K+ was greatest at 37 degrees C. However, at 25 degrees C, the secretion evoked by DMPP, but not that by the 50 mM K+, was greater after 10 min of stimulation. This data suggest that temperature differentially affects the activity of nAChRs, VSCCs, and VSSCs, resulting in differential [Na+]i and [Ca2+]i elevation, and in the [3H]NE secretion by adrenal chromaffin cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenal Glands / cytology
  • Adrenal Glands / drug effects
  • Adrenal Glands / metabolism*
  • Animals
  • Calcium Channels / drug effects
  • Calcium Channels / metabolism
  • Catecholamines / metabolism*
  • Cattle
  • Chromaffin Cells / drug effects
  • Chromaffin Cells / metabolism*
  • Ions*
  • Norepinephrine / metabolism
  • Sodium Channels / drug effects
  • Sodium Channels / metabolism
  • Temperature*
  • Tritium

Substances

  • Calcium Channels
  • Catecholamines
  • Ions
  • Sodium Channels
  • Tritium
  • Norepinephrine