Abstract
Erythrocytes from several different species were exposed to Ca2+ and the bivalent-cation ionophore A23187. The lipid composition, morphology and K+ permeability of the treated cells were investigated. Erythrocytes from human, rat, guinea pig and rabbit showed an increased concentration of 1,2-diacyl-sn-glycerol and enhanced labelling of phosphatidate with 32P, underwent echinocytosis and outward vesiculation, and rapidly released much of their intracellular K+. Pig cells showed only the K+ loss, and ox and sheep (high-K+) cells showed none of these Ca2+-evoked effects. All of the cells underwent stomatocytosis and inward vesiculation when treated externally with Clostridium perfringens phospholipase C. These results support the idea that there is a correlation between the asymmetric insertion of diacylglycerol (or ceramide) into the membrane and the shape-changes leading to microvesiculation, but they indicate that Ca2+-triggered K+ efflux and diacylglycerol production are unrelated events. Erythrocytes of chicken and turkey showed no Ca2+-stimulated K+ efflux. They showed slight ionophore A23187-stimulated vesiculation, but this appeared to be associated with the appearance in the membrane of ceramide rather than of diacylglycerol. Phospholipase C treatment caused very similar changes in morphology and phosphatidate labelling to those seen in mammalian erythrocytes.
Original language | English |
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Pages (from-to) | 495-499 |
Number of pages | 5 |
Journal | Biochemical Journal |
Volume | 166 |
Issue number | 3 |
DOIs | |
Publication status | Published - 1 Jan 1977 |
ASJC Scopus subject areas
- Biochemistry
- Molecular Biology
- Cell Biology