RESISTANCE OF CILIA TO CYTOLYTIC AGENTS 



M. E. COLLETT, 

 UNIVERSITY OF PENNSYLVANIA. 



In studying the haemolysis of erythrocytes from a series of 

 mammals, Rywosch ('07) found that the order of resistance to 

 saponin was almost the reverse of that to hypotonic NaCl. 

 He did not however offer an explanation. Hoeber in 1912 sug- 

 gested that saponin might affect the lipoids, but that the hypo- 

 tonic solutions attacked some other component of the cell. 

 K. Meyer (reviewed by Port) noted that corpuscles rich in 

 cholesterol were also most resistant to saponin. The protective 

 action of cholesterol in a cholesterol-lecithin mixture against 

 saponin has been demonstrated on artificial membranes, and 

 several workers (reviewed by Port, '10) very early cited Abder- 

 halden's analyses of erythrocytes in support of the view that 

 cholesterol is the chief factor in determining saponin resistance. 

 Hoeber ('08 and '14) used several hypotonic salt solutions, and 

 found that the phosphates were least injurious if used alone, but 

 if mixed with saponin became the most injurious of the series. 

 He interpreted this as due to the action of PO 4 on the cell colloids, 

 but not until 1914 did he offer the following more elaborate 

 theory v A cell protein which normally is stabilized by PO4, will, 

 after undergoing a change in sign (as by the action of acids), be 

 destroyed by PO4. Saponin produces such a change in sign of 

 the corpuscles and therefore attacks especially cells rich in PO4. 

 This may explain the fact that a cell resistant to hypotonic 

 NaCl is relatively susceptible to saponin. 



The present experiments were undertaken to find whether 

 this curious reversal of resistance occurs in cells of another sort 

 (ciliated cells of various marine invertebrates), and to compare 

 the effect of hypotonic NaCl with that of a hypotonic solution 

 which is at the same time balanced, e. g., dilute sea water. 



The ciliated gill filaments of several molluscs and the ciliated 

 larvae of echinoderms, molluscs and annelid worms furnished 



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