Abstract
Conclusions
From the above it becomes evident that the concentration of solutes affects both the character and amount of secretion. The depressing effect upon the amount of secretion is in direct proportion to the concentration of solutes. The amount of secretion produced following hypertonic solution is about 1/20 normal; isotonic about one-fifth normal; hypotonic one-half normal, and water four-fifths normal. This clearly indicates a selective absorption of the solutes and not a simple equilibrium phenomenon through a semi-permeable membrane. If the latter were true, water should pass into the gland from the blood and increase the amount of secretion.
As there is no significant difference between the effects of saline solution, Ringer's solution, and lactose it may be concluded that electrolytes exert no greater effect than non-electrolytes or a more balanced mixture of electrolytes such as Ringer's solution.
That the effect of an injection lasted for more than one day indicates a disturbance in secreting cell, requiring a little time to overcome. It is significant that protein in the secretion increased in the order of increase of solutes in the injected solution which is reverse to the amount of secretion.
The picture of the character of the secretion following an injections of solution approximates that of milk retained in the udder, indicating that normal milk secretion depends upon a complex selective equilibrium.
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