Abstract
A histochemical study, using the starch substrate film technique, was done to compare amylase activity in fresh-frozen cryostat sections of paired male rat parotid and submaxillary-sublingual glands, before and after pilocarpine stimulation. A quantitative procedure was followed on the same material. Amylase depletion was apparent in sections of parotid gland incubated on starch films for short periods. Quantitative estimations on adjacent sections showed an amylase depletion of about 50%. In the submaxillary-sublingual gland, amylase was demonstrable in the blood vessels in both unstimulated and stimulated material and there appeared to be a higher concentration of the enzyme in the latter. Quantitative assays on adjacent sections demonstrated a very considerably raised level of amylase activity in the stimulated submaxillary gland. It was concluded that the histochemically demonstrable amylase in the blood vessels of the submaxillary and sublingual glands was blood amylase and that the raised level following pilocarpine stimulation might be interpreted as a passage to the blood of enzymes produced by other glands under the same stimulus.