32 The Anatomy of the Salivary Glands 



only partly corrected by thyroxin and testosterone. Studies on 

 enzyme content of the glands show that the protease and phos- 

 phatase content of the glands is strongly affected by the develop- 

 ment of the granular tubules, but amylase and arginase is little 

 changed (Junqueira, Fajer, Rabinovitch and Frankenthal, 1949; 

 Kochakian, Endahl and Hall, 1955). Little work has been done on 

 changes in salivary glands in senescence. Kurtz (1954) found in the 

 rat that the mitochondria changed from the plump forms found in 

 young adults to long rather irregular forms in the senile rat and he 

 also found irregularities in the Golgi apparatus. 



Atrophy of the salivary glands occurs after duct ligation. This is 

 a rapid process and is complete within a week. The most marked 

 changes occur in the acini which decrease in size, the cells become 

 vacuolated and almost completely disappear. The ducts remain as 

 a skeleton of the gland structure and indeed undergo hyperplasia 

 so that a multi-layered duct epithelium becomes the rule. There is 

 also a proliferation of connective tissue (Junqueira and Rabino- 

 vitch, 1954; Dietz, 1955; Bhaskar, Borden and Weinman, 1956; 

 Standish and Shafer, 1957). On removal of the duct ligature the 

 histology and biochemistry of the gland slowly returns more or 

 less to normal even if the ligature had remained on the ducts for as 

 long as a year. Partial regeneration of the rat submaxillary gland 

 has been reported after subtotal resection (Milstein, 1950). The 

 first changes are a thickening in the duct epithelium with numer- 

 ous mitoses, and the formation of branch ducts; subsequently 

 acini bud off these new ducts. 



REFERENCES 



babkin, b. p. (1944). Secretory mechanisms of the digestive glands. Hoeber, 

 New York. I 



Bennett, h. s. (1956). The concepts of membrane flow and membrane 

 vesiculation as mechanisms for active transport and ion pumping. 

 J. Biophys. Biochem. CytoL, 2, Suppl., 99-103. 



bernhard, w., f. haguenau, A. gautier and c. oberling (1952). La struc- 

 ture submicroscopique des elements basophiles cytoplasmiques dans 

 le foie, le pancreas, et les glands salivaires. Z. Zellforsch., 37, 281-300. 



bhaskar, s. n., t. e. borden and j. p. weinman (1956). Experimental 

 obstructive adenitis in the mouse, y. dent. Res., 35, 852. 



bixler, d., r. c. Webster and J. c. muhler (1957). The effect of testo- 

 sterone, thyroxine, and cortisone on the salivary glands of the hypo- 

 physectomized rat. y. dent. Res., 36, 566-570. 



