Extracellular ATP activates different signalling pathways in rat Sertoli cells

Area of Science:

• Cell Biology
• Neuroscience
• Endocrinology

Background:

• Sertoli cells play a crucial role in male reproduction.
• Extracellular ATP (ATPe) is a signaling molecule with diverse cellular effects.
• Understanding ATPe's impact on Sertoli cell function is vital for reproductive health research.

Purpose of the Study:

• To investigate the effects of extracellular ATP (ATPe) on plasma membrane potential and intracellular calcium concentrations ([Ca2+]i) in rat Sertoli cells.
• To elucidate the signaling pathways involved in ATPe-mediated cellular responses.

Main Methods:

• Rat Sertoli cells were stimulated with ATPe and other nucleotides.
• Plasma membrane potential and [Ca2+]i were monitored using fluorescent dyes (bis-oxonol and fura-2/AM).
• Ionic changes were analyzed under various conditions, including altered extracellular ion concentrations and treatment with specific inhibitors (thapsigargin, verapamil, nifedipine, pertussis toxin).

Main Results:

• ATPe induced rapid plasma membrane depolarization dependent on extracellular Na+ influx.
• ATPe caused a biphasic increase in [Ca2+]i: an initial spike from intracellular stores and a sustained phase dependent on Ca2+ influx via voltage-operated calcium channels (VOCCs).
• Pertussis toxin partially reduced ATPe-induced responses, indicating involvement of pertussis toxin-sensitive G-proteins.

Conclusions:

• Rat Sertoli cells possess P2-purinergic receptors activated by ATPe.
• ATPe triggers distinct signaling pathways: Na+ influx causing depolarization and Ca2+ release/influx.
• These findings reveal complex ATPe-mediated signaling in Sertoli cells, potentially impacting reproductive function.