Elsevier

Cell Calcium

Volume 23, Issue 1, January 1998, Pages 33-42
Cell Calcium

Research
Voltage dependent calcium channels in adrenal glomerulosa cells and in insulin producing cells

https://doi.org/10.1016/S0143-4160(98)90072-0Get rights and content

Abstract

We have examined the structure and function of Ca2+ channels in excitable endocrine cell types, in rat adrenal glomerulosa cells and in two insulin producing cell types, the rat pancreatic β cell and the INS-1 cell line. In previous studies on glomerulosa cells, we observed low (T-type) and high threshold (L-type) voltage dependent Ca2+ currents in addition to a K+ induced inward rectifying Ca2+ current (Igl). β cells are known to exhibit T-, L- and N-type currents. We have now found that INS-1 cells also show low threshold (T-type) and high threshold Ca2+ currents. The latter was further resolved by organic inhibitors into L-type and P/Q-type currents and no Igl was detected.

The expression of the pore-forming α1 subunit of voltage dependent Ca2+ channels was studied by means of reverse transcription-polymerase chain reaction (RT-PCR), followed by restriction enzyme mapping and/or sequencing. Both in glomerulosa and pancreatic β cells, the neuroendocrine (D) class of the α1 subunit, known to be responsible for L-type current, represents the majority of the PCR product. Comparable amounts of the neuroendocrine (D) and the neuronal A-type α1 subunits dominate the message in INS-1 cells.

Different characteristics of Ca2+ currents in these cell types is discussed in view of the channel repertoire.

References (42)

  • E.D. Kennedy et al.

    Glucose-stimulated insulin secretion correlates with changes in mitochondrial and cytosohc Ca2+ in aequorin-expressing INS-1 cells

    J Clin Invest

    (1996)
  • A. Spät et al.

    Angiotensin II and potassium activate different calcium entry mechanisms in rat adrenal glomerulosa cells

    J Endocrinol

    (1989)
  • E. Madarász et al.

    Development of oxytocinergic neurons in monolayer cultures derived from embryonic, fetal and postnatal rat hypothalami

    J Neuroendocrinol

    (1992)
  • M. Asfari et al.

    Establishment of 2-mercaptoethanol-dependent differentiated insulin-secreting cell lines

    Endocrinology

    (1992)
  • F. Sanger et al.

    DNA sequencing with chain-terminating inhibitors

  • O.P. Hamill et al.

    Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches

    Pflügers Arch

    (1981)
  • L. Hunyady et al.

    Dihydropyridinesensitive initial component of the ANG III-induced Ca2+ response in rat adrenal glomerulosa cells

    Am J Physiol Cell Physiol

    (1994)
  • P. Várnai et al.

    Activation of calcium current in voltage-clamped rat glomerulosa cells by potassium ions

    J Physiol (Lond)

    (1995)
  • P. Várnai et al.

    Electrophysiological study on the high K+ sensitivity of rat glomerulosa cells

    Pfügers Archiv European Journal of Physiology

    (1998)
  • C.J. Cohen et al.

    Ca channels in adrenal glomerulosa cells: K+ and angiotensin II increase T-type Ca channel current

  • T. Durroux et al.

    Three components of the calcium current in cultured glomerulosa cells from rat adrenal gland

    J Physiol (Lond)

    (1988)
  • Cited by (54)

    • Chapter 16 Insulin Granule Biogenesis, Trafficking and Exocytosis

      2009, Vitamins and Hormones
      Citation Excerpt :

      For example, lipid‐derived products such as long chain‐coenzyme A derivatives activate mouse and human KATP channels and hyperpolarize β cell thereby reducing insulin secretion (Branstrom et al., 1997, 2004). In any case, the closure of ATP‐sensitive K+ channels results in cellular depolarization that activates L‐type VDCCs resulting the influx of extracellular Ca+2 (Horvath et al., 1998; Keahey et al., 1989; Ligon et al., 1998). The requirement for extracellular Ca+2 influx for insulin secretion has been well documented by numerous investigators and includes the use of Ca+2 ionophores to induce secretion, blockade of secretion by removal of extracellular Ca+2 (Ashby and Speake, 1975; Eddlestone et al., 1995) and directed monitor of cytosolic free Ca2+ (Prentki and Wollheim, 1984).

    • The Two-pore Domain K<sup>+</sup> Channel, TRESK, Is Activated by the Cytoplasmic Calcium Signal through Calcineurin

      2004, Journal of Biological Chemistry
      Citation Excerpt :

      Since the exon boundaries of our artificially constructed human 2PK+ channel were only probable at the time of its cloning, we cloned TRESK also from a natural source, mouse cerebellar RNA, by RT-PCR. Total RNA was extracted from different mouse tissues as previously described (18). The complete coding region of mouse TRESK was PCR-amplified with -8s (5′-ATCgaattcCAAGAGGATGGAGGCTGAGG-3′) and 1185a (5′-GCGctcgagTTACCAAGGTAGCGAAACTTCCCTTTG-3′) primers (designed on the basis of mouse genomic sequences) from cerebellar RNA after reverse transcription with Moloney murine leukemia virus reverse transcriptase enzyme (Promega, Madison, WI).

    • Understanding Insulin and Insulin Resistance

      2022, Understanding Insulin and Insulin Resistance
    View all citing articles on Scopus
    View full text