Modulation of neutrophil migration by captopril

Area of Science:

• Immunology
• Pharmacology

Background:

• Neutrophils play a role in the therapeutic effects of captopril.
• The precise mechanisms by which captopril influences neutrophil function are not fully understood.

Purpose of the Study:

• To investigate the effect of captopril on neutrophil migration.
• To elucidate the signaling pathways involved in captopril-induced neutrophil migration.

Main Methods:

• Rabbit peritoneal neutrophils were used to study migration.
• Neutrophils were pretreated with pertussis toxin and 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB).
• Cyclic GMP (cGMP) levels and the effects of nitric oxide (NO) generation inhibitors were assessed.

Main Results:

• Captopril significantly enhanced neutrophil migration in a concentration-dependent manner.
• The stimulatory effect was partly chemokinetic and partly chemotactic.
• Pertussis toxin inhibited captopril-induced migration, indicating involvement of a G protein.
• DTNB abolished the stimulatory effect, highlighting the requirement for intact sulfhydryl groups.
• Both captopril and its disulfide form increased neutrophil cGMP levels.
• Methylene blue and LY-83583 blocked cGMP and migration enhancement, suggesting cGMP mediation.
• NO generation inhibitors had no effect on captopril-induced migration.

Conclusions:

• Captopril enhances neutrophil migration via a pertussis toxin-sensitive G protein and cGMP signaling pathway.
• The mechanism requires intact cell surface sulfhydryl groups and does not involve nitric oxide.
• These findings contribute to understanding captopril's immunomodulatory effects.