Effect of Ropivacain and Bupivacain on Calcium-Related and G-Protein Coupled Processes in PMNs: A Human In-Vitro...

Area of Science:

• Immunology
• Cell Biology
• Pharmacology

Background:

• Polymorphonuclear leukocytes (PMNs) play a critical role in immune responses.
• Local anesthetics like bupivacaine and ropivacaine can influence cellular functions.
• G-protein-coupled receptor (GPCR) signaling and intracellular calcium are key regulators of PMN behavior.

Purpose of the Study:

• To investigate the effects of bupivacaine and ropivacaine on PMN migration and NETosis.
• To elucidate the roles of intracellular calcium and GPCR signaling in these processes.

Main Methods:

• PMNs were isolated from healthy volunteers.
• In vitro chemotaxis assays were performed using a collagen matrix and fMLP gradient.
• Cells were treated with bupivacaine, ropivacaine, calcium chelator (BAPTA AM), GPCR inhibitor (gallein), and PLC inhibitor (U-73122).
• PMN migration and NETosis were tracked using fluorescence microscopy over 6 hours.

Main Results:

• Bupivacaine induced earlier NETosis compared to ropivacaine.
• Both anesthetics led to an earlier cessation of PMN migration.
• Intracellular calcium chelation showed a concentration-dependent effect on migration.
• Gallein and U-73122 treatments resulted in earlier NETosis and increased intracellular calcium.

Conclusions:

• Intracellular calcium is vital for neutrophil migration but plays a minor role in NETosis.
• Inhibition of Gβγ and PLC signaling accelerates NETosis and elevates intracellular calcium.
• No additional GPCR pathway effect of ropivacaine was detected.