COMPLEMENT AND VITAMINS 231 



guinea-pig serum. C'l is a euglobulin containing 2-7 per cent, carbohydrate. 

 A muco-euglobulin fraction of carbohydrate content 10'3 per cent, contains C'2 

 and C'4. The C'2 is heat-labile and the C'4 relatively heat-stable. According to 

 Pilleraer, Seifter and Ecker (1941) C'4 is a carbohydrate, whose carbonyl groups 

 are specifically attacked during inactivation by ammonia and other compounds, 

 and which is normally carried by C'2, the two forming a globulin-carbohydrate 

 complex. C'l accounts for 0-6 per cent., and C'2 and C'4 for 0-17 per cent, of 

 the total serum protein. 



More recently Ecker and his colleagues have made a similar analysis of human 

 complement. Four components are present with properties analogous to the four 

 in guinea-pig sera. C'l has been isolated, and closely resembles guinea-pig C'l ; 

 both have similar electrophoretic mobilities and sedimentation constants. The 

 carbohydrate content of human C'l was slightly higher, 3-2-3-7 per cent., and 

 so was the apparent isolectric point, pH 6-0-6-4 as against pH 5-2-5-4. In human 

 serum, C'l constituted about 0-6-0-8 per cent, of the total serum protein. Of all 

 four components in the two species, only C'3 was completely interchangeable in 

 hsemolytic tests. Human C'l and C'4 could replace the guinea-pig C'l and C'4, 

 and guinea-pig C'2 could replace human C'2, but the corresponding converse 

 replacements were either less effective or ineffective (Ecker, Pillemer and Seifter 

 1943, Seifter, Pillemer and Ecker 1943, Pillemer, Seifter, San Clemente and Ecker 

 1943). 



Complement and Vitamins. 



The relation of complement to vitamin C has received much attention in recent years. 

 The reduced complement titres in guinea-pig sera during the winter montlis (Tokunaga 

 1928, Marsh 1936, Horgan 193G) suggests a dietary deficiency associated with a lack of 

 green food. In the guinea-pig Harde and Thomson (1935) demonstrated an association 

 between vitamin C intake and coiiiplement titres ; Ecker, PiUemer, Wertheimer and 

 Grodis (1938) and Chu and Chow (1938) a correlation between complement and serum 

 vitamin C levels. The connection between the two substances may lie in the capacity 

 of ascorbic acid to take part in redox mechanisms in the blood (Ecker, PiUemer, Martiensen 

 and Wertheimer 1938). Ascorbic acid reactivates both complement deprived of its C'3 and 

 complement inactivated by oxidation, and increases the titre of complement from scorbutic 

 guinea-pigs. Hexoxidase, which oxidizes ascorbic acid, will reduce complement activity 

 in vitro, apparently by acting on C'3. 



On the other hand, Zilo (1915) and Koch and Smith (1924) found high complement titres 

 in scorbutic animals, and, like Heinicke (1934) and Kapnickand Cope (1940), were unable 

 to demonstrate any relation between complement and ascorbic acid levels (see also 

 Crandon, Lund and" Dill 1940, Feller et al. 1942). 



These results have been confirmed (Spink et al. 1942, Agnew et al. 1942) : in human 

 subjects with low serum ascorbic acid the injection of ascorbic acid did not raise the 

 complement titre ; nor was oxidation of ascorbic acid with CuClj accompanied by a 

 reduction of the complement titre. In guinea-pigs, variations in serum ascorbic acid 

 induced by diet were not reflected in complement titres. Similarly Kodicek and Traub 

 (1943) could not alter complement levels in any significant manner by variations of ascorl)ic 

 acid intake in guinea-pigs ; they suggested that since there was a wide normal variation 

 in complement titres, previously observed associated variation in the levels of the two 

 substances may have been fortuitous. Moreover, the in vitro bactericidal power of human 

 blood was not altered by an increase or decrease of ascorbic acid (Spink, Agnew, Mickelsen 

 and Dahl 1942). These authors, however, noted differences between the efficacy of 

 sjmthetic ascorbic acid and native vitamin C, and the discrepancies may perhaps depend 

 on the action of substances associated with native vitamin C. The vitamin is certainly 



