Gap junction-mediated intercellular diffusion of Ca2+ in cultured human corporal smooth muscle cells

G. J. Christ, A. P. Moreno, A. Melman, David C. Spray

Research output: Contribution to journalArticle

141 Citations (Scopus)

Abstract

Ratio imaging using the calcium-sensitive probe fura-2 was employed to study intracellular calcium concentrations and intercellular calcium flux through gap junctions in homogeneous vascular smooth muscle cell cultures derived from the human corpora cavernosa. Microinjection techniques demonstrated that fura-2 free acid was freely diffusible through gap junctions between cultured cells. The resting intracellular calcium level in fura-2-loaded cells was 176.9 ± 10.5. A robust increase in intracellular calcium was seen in response to both phenylephrine and the calcium ionophore A23187. Microinjection of Ca2+ into individual smooth muscle cells always resulted in significant, although temporally delayed, increases in intracellular calcium levels in adjacent cells; this intercellular calcium flux was reversibly blocked by inhibition of gap junctional communication with 2 mM heptanol. However, although microinjection of D-myo-inositol 1,4,5- trisphosphate [Ins(1,4,5)P3] into individual smooth muscle cells always produced significant increases in intracellular calcium levels in the injected cell, the intercellular spread of Ca2+ in response to Ins(1,4,5)P3 was more variable than for Ca2+ injections. These studies demonstrate that Ca2+, and perhaps Ins(1,4,5)P3 as well, can diffuse between smooth muscle cells through gap junction channels.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Cell Physiology
Volume263
Issue number2 32-2
StatePublished - 1992

Fingerprint

Gap Junctions
Smooth Muscle Myocytes
Muscle
Cells
Calcium
Microinjections
Fura-2
Heptanol
Fluxes
Inositol 1,4,5-Trisphosphate
Calcium Ionophores
Calcimycin
Phenylephrine
Vascular Smooth Muscle
Cell culture
Cultured Cells
Cell Culture Techniques
Communication
Imaging techniques
Injections

Keywords

  • α-adrenergic receptors
  • erectile dysfunction
  • fura-2
  • inositol trisphosphate
  • penis
  • vascular smooth muscle

ASJC Scopus subject areas

  • Cell Biology
  • Clinical Biochemistry
  • Physiology

Cite this

Gap junction-mediated intercellular diffusion of Ca2+ in cultured human corporal smooth muscle cells. / Christ, G. J.; Moreno, A. P.; Melman, A.; Spray, David C.

In: American Journal of Physiology - Cell Physiology, Vol. 263, No. 2 32-2, 1992.

Research output: Contribution to journalArticle

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