The uptake of amines by polymorphonuclear leukocytes

Area of Science:

• Pharmacology
• Cell Biology
• Immunology

Background:

• Muscarinic and beta-adrenergic ligands bind to polymorphonuclear leukocytes.
• This association exhibits characteristics of high-affinity, saturable accumulation.

Purpose of the Study:

• To differentiate ligand association from specific receptor binding in polymorphonuclear leukocytes.
• To investigate the mechanism of permeable basic amine accumulation in these cells.

Main Methods:

• Characterizing ligand association based on temperature dependence, pH sensitivity, energy requirements, and inhibition by ionophores and permeable basic amines.
• Analyzing the effect of permeable basic amines on specific receptor binding.

Main Results:

• Ligand association differs from specific receptor binding due to its temperature dependence, pH sensitivity, energy requirement, and inhibition by ionophores.
• Permeable basic amines accumulate in acidic lysosomes within polymorphonuclear leukocytes.
• This amine accumulation can be inhibited independently of specific receptor binding.

Conclusions:

• The observed ligand association is distinct from specific receptor binding and likely involves lysosomal accumulation.
• Permeable basic amines accumulate in acidic lysosomes, providing a method to distinguish this process from direct receptor interactions.