234 Metabolism 



similar way to that found by Anrep, Khan, Stavraky and others 

 (Langstroth, McRae and Stavraky, 1938) in being readily exhaust- 

 ible and in being regenerated at a very slow rate of about 0-5 per 

 cent/hour. On the other hand, proteins of duct origin were not 

 exhausted by stimulation and were synthesized at a higher rate 

 more comparable to that found in the pancreas. It appears that 

 protein of duct origin is not an important fraction of the, sub- 

 maxillary gland secretion. Fritz (1955) found that N 15 labelled 

 glycine appeared in salivary gland proteins to about the same extent 

 as in liver proteins, but as the shortest period of study was 18 

 hours and no distinction was made between structural proteins 

 and secretory products this study is not very helpful. Martin (un- 

 published) has found that C 14 valine is incorporated into salivary 

 proteins, but the rate of appearance is quite slow. Similar results 

 have been obtained in the pancreas (Junqueira, Hirsch and Roth- 

 schild, 1955 ; Siekevitz and Palade, 1958). Nothing is known of the 

 rate of incorporation of carbohydrates in the mucoproteins of 

 saliva. There is no change whatsoever in the content of RNA or 

 DNA in the cell following starvation or physiological exhaustion 

 of the salivary gland or pancreas (Hokin and Hokin, 19546; Daly 

 and Mirsky, 1952). 



REFERENCES 



anrep, G. v. and R. k. cannan (1922). The blood sugar metabolism of the 

 submaxillary gland. J. Physiol., 56, 248-258. 



(1923). The blood sugar metabolism of the submaxillary gland, jf. 



Physiol., 57, 1-6. 



anrep, G. v. and h. N. khan (1923). The metabolism of the salivary 

 glands. V. The process of reconstruction of the submaxillary gland. 

 J. Physiol, 58, 302-309. 



barcroft, j. (1901). The gaseous metabolism of the submaxillary gland. 

 Part III. The effect of chorda activity on the respiration of the gland. 

 J. Physiol, 27, 31-47- 



— (19 14). The respiratory function of the blood. University Press, Cam- 

 bridge. 



barcroft, j. and T. kato (1916). Effects of functional activity in striated 

 muscle and the submaxillary gland. Philos. Trans. B., 207, 149-182. 



barcroft, j. and F. muller (1912). The relation of blood flow to metabol- 

 ism in the submaxillary gland. J. Physiol, 44, 259-264. 



barcroft, j. and h. piper (1912). The gaseous metabolism of the sub- 

 maxillary gland with reference especially to the effect of adrenaline 

 and the time relation of the stimulus to the oxidation process. J. 

 Physiol, 44, 359-373- 



