Olivieri O, Guarini P, Negri M, Bassi A, Corrocher R, Biffanti S, De Matteis MC, Vettore L. Increased proteolytic activity of erythrocyte membrane in spur cell anaemia.
Br J Haematol 1988;
70:483-9. [PMID:
3064803 DOI:
10.1111/j.1365-2141.1988.tb02521.x]
[Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
In a case of 'spur cell anaemia' (SCA) a reduced esterified/free cholesterol ratio was found in plasma, in LDL and HDL fractions and an increased cholesterol/phospholipid (C/PL) molar ratio in erythrocyte membrane. Cation transport was normal with the exception of Li-Na counter-transport was decreased. An increased intrinsic membrane proteolytic activity (IMPA) was demonstrated by the generalized reduction or, sometimes, disappearance of protein bands on SDS-PAGE in patient ghosts when the proteolysis was allowed. This characteristic was found to be transferable to normal cells by incubation in SCA-plasma; moreover membrane C/PL molar ratio was augmented after incubation. Normal plasma was not able to normalize IMPA of SCA cells 'in vitro', even if it induced a remarkable decrease of membrane C/PL molar ratio. Nevertheless IMPA normalization did occur 'in vivo', when the SCA cells were exposed to therapeutic 'plasma exchange' (3.3 litre/week). The results suggest the following conclusions: (a) in our SCA patient there is an increased IMPA; (b) this feature, as well as membrane lipid alteration, is transferable to normal erythrocytes; (c) this case seems to demonstrate, for the first time in our knowledge, a modulating effect of plasma on IMPA in erythrocytes.
Collapse