Calcium and potassium currents in spermatogenic cells dissociated from rat seminiferous tubules

J Physiol. 1984 Nov;356:135-49. doi: 10.1113/jphysiol.1984.sp015457.

Abstract

The electrophysiological properties of the cell membrane of rat spermatogenic cells were studied using the whole-cell variation of the patch-electrode voltage-clamp technique. In late primary spermatocytes and early spermatids isolated from adult testis, a transient inward current followed by a slowly developing outward current was produced when the membrane potential was made more positive than -60 mV. Early spermatogenic cells which consist of spermatogonia and early spermatocytes were isolated either from new-born rats (12-14 days old) of from adult cryptorchid rats 15-21 days after the operation. In early spermatogenic cells, some showed a slowly developing outward current with negligible initial inward current, while others showed a recognizable inward current followed by the slowly developing outward current. The inward currents are identified as Ca2+-carried current, since replacement of external Ca2+ with Mn2+ reversibly diminished the current whereas Ba2+ or Sr2+ substituted for Ca2+. The reversal potential of the outward current changed from -65 to -12 mV when [K+]o was raised from 5 to 100 mM. The outward current was independent of [Ca2+]o and was blocked by tetraethylammonium chloride. Thus the current was identified as membrane-potential-dependent K+ current. During spermatogenesis from spermatogonia to early spermatids, the density of Ca2+ current increased while the K+ current density decreased significantly.

Publication types

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

MeSH terms

  • Animals
  • Calcium / physiology*
  • Cations, Divalent / physiology
  • Cryptorchidism / physiopathology
  • In Vitro Techniques
  • Male
  • Membrane Potentials / drug effects
  • Potassium / physiology*
  • Rats
  • Rats, Inbred Strains
  • Seminiferous Tubules / physiology*
  • Spermatogenesis*
  • Spermatozoa / drug effects
  • Spermatozoa / physiology*
  • Testis / physiology*
  • Tetraethylammonium
  • Tetraethylammonium Compounds / pharmacology

Substances

  • Cations, Divalent
  • Tetraethylammonium Compounds
  • Tetraethylammonium
  • Potassium
  • Calcium