# Erythrocytes membrane fluidity changes induced by adenylyl cyclase cascade activation: study using fluorescence recovery after photobleaching

## TL;DR

This study shows that activating a specific cell signaling pathway increases the fluidity of red blood cell membranes, as observed through changes in lipid diffusion.

## Contribution

The novel finding is that adenylyl cyclase cascade activation increases erythrocyte membrane fluidity through phospholipid mobility changes.

## Key findings

- Stimulation of adrenergic receptors with epinephrine or metaproterenol significantly increased membrane fluidity in erythrocytes.
- Activation of protein kinase A with a cAMP analog also increased fluidity, but the effect was less pronounced.
- The increased fluidity is attributed to weakened interactions between membrane proteins and the cytoskeleton.

## Abstract

In this study, fluorescence recovery after photobleaching (FRAP) experiments were performed on RBC labeled by lipophilic fluorescent dye CM-DiI to evaluate the role of adenylyl cyclase cascade activation in changes of lateral diffusion of erythrocytes membrane lipids. Stimulation of adrenergic receptors with epinephrine (adrenaline) or metaproterenol led to the significant acceleration of the FRAP recovery, thus indicating an elevated membrane fluidity. The effect of the stimulation of protein kinase A with membrane-permeable analog of cAMP followed the same trend but was less significant. The observed effects are assumed to be driven by increased mobility of phospholipids resulting from the weakened interaction between the intermembrane proteins and RBC cytoskeleton due to activation of adenylyl cyclase signaling cascade.

The online version contains supplementary material available at 10.1007/s00249-024-01707-x.