64 STUDIES ON ALKALINE PHOSPHATASE 



collagen was laid down a high concentration of phosphatase ap- 

 peared apparently on the collagen fibres themselves. We also 

 observed, as Bourne had done earlier, that phosphatase was pres- 

 ent in the hair follicles and thus presumably was concerned in 

 some way with the formation of fibrous keratin. On the other 

 hand, we observed no indication that skin-keratin formation 

 was associated with phosphatase activity. The association of 

 formation of two fibrous proteins with alkaline phosphatase was 

 suggestive, though it did not necessarily follow that there was 

 any causal relationship between the two substances. To obtain 

 further leads on this problem, we collaborated with Dr. Kodicek 

 in a study of skin wounds in guinea pigs, both normal and vita- 

 min-C-deficient animals being used. We found that there was a 

 close parallelism between degree of vitamin C deficiency, the 

 rate of formation of collagen, and the rate of appearance of alka- 

 line phosphatase. We were surprised to find that the optimal 

 rate of wound healing required a dosage of 10 milligrams of vita- 

 min C per animal per day. Bourne (1943) had made some 

 similar observations on the healing of cavities in bones. He ob- 

 served that the first step was the formation of protein fibres in 

 the cavity, and that these protein fibres were very rich in alka- 

 line phosphatase. 



We were unable to discover a causal connection between pro- 

 tein synthesis and alkaline phosphatase. It seemed, however, 

 possible that one of the best methods of pursuing the matter 

 would be to investigate the formation of other fibrous proteins 

 such as silk. J. R. G. Bradfield has pursued this matter. Al- 

 though he has not been able to establish the exact site of synthe- 

 sis of silk proteins, he was able to show that the secreting cells of 

 the glands which are actively engaged in secretion of silk protein 

 have in one region of their cytoplasm, bordering on the lumen 

 of the gland concerned, a high concentration of active phospha- 

 tase. On the other hand, Helen Brown, in a study of the forma- 

 tion of the protein which constitutes the byssus thread of Mytilus, 

 has been unable to detect an association of the protein with alka- 

 line phosphatase at any stage. This latter observation recalls 

 the lack of association of skin keratin formation with alkaline 

 phosphatase. On the other hand, in this connection it is notable 

 that the horny teeth of Myxine and the horns of deer involved 

 fibrous keratin formation associated with alkaline phosphatase. 



