Life-Span of Blood Components

Treatment of erythrocytes with neuraminidase (Stewart et al 1955, 1957, Gardner et al 1961, Perona et al 1964) or intravenous injection of this enzyme (Landaw et al 1973) leads to a drastic decrease of their half-life in the circulation, in man it is reduced from about 120 days to a few hours (Halbhuber et al 1972, Durocher et al 1975, Jancik et al 1978). In vitro experiments revealed that the recognition mechanism of asialo-erythrocytes has very much in common with the uptake of soluble asialo-glycoproteins, though the blood cells are degraded exclusively in Kupffer cells (Halbhuber er al 1972), while asialo-glycoproteins are taken up by hepatocytes (Ashwell and Morell 1974). 

It is necessary to stress, however, that adhesion of asialo-erythrocytes does not necessarily entail their uptake and degradation (Kuster and Schauer 1981). Furthermore, the complement system is apparently involved in the endocytosis of attached cells, because heat inactivation of serum reduces considerably the rate of phagocytosis. 

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