| Autor: |
Murakami, Masataka, Yoshimura, Keiichi, Segawa, Akihisa, Loffredo, Felice, Riva, Alessandro |
| Předmět: |
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| Zdroj: |
European Journal of Morphology; Oct2000, Vol. 38 Issue 4, p243, 5p |
| Abstrakt: |
Whole gland perfusion technique was applied torat parotid glands to assess whether amylase affects fluid secretion. Controlperfusion without any secretagogue evoked no spontaneous secretion. Carbachol(CCh 1 μM) induced both amylase and fluid secretion with distinctive kinetics.Fluid secretion occurred constantly at 40-120 μl/g-min (average plateauwas 60 μl/g-min), whereas amylase secretion exhibited an initial peak (10mg maltose/30 s per g wet w. of the gland), followed by a rapid decrease toreach a plateau level of 1 mg maltose/30 s later than 1.5-2 min. Isoproterenol(Isop 1 μM) alone did not induce fluid secretion although it evoked amylasesecretion as measured in isolated perfused acini. Addition of Isop duringCCh stimulation evoked a rapid and large rise in amylase secretion to 15 mgmaltose/30 s accompanied by the increase in oxygen consumption. However, thefluid secretion exhibited a rather gradual decrease. These findings suggestthat control of salivary fluid secretion is independent of the amylase secretionsystem induced by CCh and/or Isop. Morphological observations carried outby HR SEM and TEM revealed exocytotic profiles following Isop stimulation.CCh stimulation alone seldom showed -exocytotic profiles, suggesting a lowincidence of amylase secretion during copious fluid secretion. Combined stimulationof CCh and Isop induced both vacuolation and exocytosis along intercellularcanaliculi. During washout of secretagogues, lysosomal digestion of excessmembrane took place. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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