Metabolism 23 1 



1959). Deutsch and Raper (1936) reported that no change in 

 oxygen consumption was produced by adrenaline in the cat parotid 

 or the dog and rabbit parotid and submaxillary; however, Hokin 

 and Sherwin (1957) obtained a considerable increase in respiration 

 with adrenaline in the rabbit parotid and submaxillary glands using 

 somewhat higher doses. Four weeks following chorda section the 

 resting oxygen consumption of the submaxillary gland of the cat 

 was reduced by one-third and the extra oxygen consumption per 

 ml. of saliva was reduced proportionately as was the maximal rate 

 of oxygen usage of the gland (Stromblad, 1959). 



Not much is known of the substrates utilized by the salivary 

 gland in situ. Anrep and Cannan (1922, 1923) measured the utili- 

 zation of glucose by the dog submaxillary gland and found at rest 

 an uptake of about 60 /-eg/g. min (0-33 /«M/g. min) or roughly 0-33 

 jtiM glucose per //M of oxygen. During activity glucose utilization 

 increased up to eightfold, running roughly in parallel with the 

 oxygen usage. It is of course not certain that all of this glucose is 

 used in respiration ; some may be used as a carbon source in synthe- 

 sis of the secretory product. Small amounts of lactate are formed 

 by the resting gland and during activity an increased output occurs, 

 particularly during the first minute, a period when the increase in 

 respiration lags behind the rate of secretion (Bergonzi and Bolcato, 

 1930; Bergonzi, 1931; Ferrari and Hober, 1933; Wills, 1941). 

 Ferrari and Hober (1933) found with perfused glands an increase 

 in lactate output when cyanide (0-5-2 mM) was added to the per- 

 fusion fluid and a reduction with iodacetate (0-01-0-05 mM). Only 

 modest changes in the gland lactate content have been reported 

 after stimulation, but in part this may be due to inadequate experi- 

 mental technique. Moderate reduction in glycogen and creatine 

 phosphate have been reported after stimulation (Bergonzi and 

 Bolcato, 1930; Himwich and Adams, 19306; Northup, 1935). ,« 

 Anaerobic incubation of minced submaxillary glands leads to 

 quantitative conversion of glycogen to lactate (Himwich and 

 Adams, 1930^). 



In vitro the metabolic behaviour of salivary slices or minces has 

 interesting features. Under anaerobiosis, with cyanide, iodacetate 

 or fluoride the metabolic effect of acetylcholine is no longer 

 present. Resting metabolism is changed little by the addition of 

 extraneous substrates (glucose, fructose, succinate, lactate or pyru- 

 vate), and indeed in the absence of added substrate a steady Qo 2 



