alpha1H T-type Ca2+ channel is the predominant subtype expressed in bovine and rat zona glomerulosa

Am J Physiol Cell Physiol. 2001 Feb;280(2):C265-72. doi: 10.1152/ajpcell.2001.280.2.C265.


The low voltage-activated (T-type) Ca2+ channel has been implicated in the regulation of aldosterone secretion from the adrenal zona glomerulosa by extracellular K+ levels, angiotensin II, and ACTH. However, the identity of the specific subtype mediating this regulation has not been determined. We utilized in situ hybridization to examine the distribution of three newly cloned members of the T-type Ca2+ channel family, alpha1G, alpha1H, and alpha1I, in the rat and bovine adrenal gland. Substantial expression of only the mRNA transcript for the alpha1H-subunit was detected in the zona glomerulosa of both rat and bovine. A much weaker expression signal was detected for the alpha1H transcript in the zona fasciculata of bovine. Whole cell recordings of isolated bovine adrenal zona glomerulosa cells showed the native low voltage-activated current to be inhibited by NiCl2 with an IC50 of 6.4 +/- 0.2 microM. Because the alpha1H subtype exhibits similar NiCl2 sensitivity, we propose that the alpha1H subtype is the predominant T-type Ca2+ channel present in the adrenal zona glomerulosa.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Calcium Channels, T-Type / drug effects
  • Calcium Channels, T-Type / metabolism*
  • Cattle
  • Male
  • Membrane Potentials / drug effects
  • Membrane Potentials / physiology
  • Molecular Sequence Data
  • Nickel / pharmacology
  • RNA, Messenger / drug effects
  • RNA, Messenger / metabolism*
  • Rats
  • Rats, Sprague-Dawley
  • Species Specificity
  • Steroid 11-beta-Hydroxylase / metabolism
  • Tyrosine 3-Monooxygenase / metabolism
  • Zona Glomerulosa / cytology
  • Zona Glomerulosa / drug effects
  • Zona Glomerulosa / metabolism*


  • Calcium Channels, T-Type
  • RNA, Messenger
  • nickel chloride
  • Nickel
  • Steroid 11-beta-Hydroxylase
  • Tyrosine 3-Monooxygenase

Associated data

  • GENBANK/AF236638
  • GENBANK/AF236639
  • GENBANK/AF236640