OBJECTIVETo study the ultrastructure of parotid glands, lacrimal glands and pituitary glands between miniature pig and mouse.

METHODSFive adult miniature pigs and 5 mice were studied. Ultrastructure of their parotid glands, lacrimal glands, and pituitary glands was observed.

RESULTSThe secretary granules in acinar cell of miniature pig parotid glands showed higher density and more aequalis than those of mice. The cell apparatus in acinar cell of mouse parotid glands were more plentiful than those of miniature pigs. The secretary granules on blood vessel wall were richer in parotid gland of miniature pigs compared with mouse parotid gland. Lacrimal gland had the similar ultrastructure to parotid gland in these two animals. Many blood vessel antrum were found in pituitary glands of these two animals.

CONCLUSIONSCompared with mouse parotid glands, there are more secretary granules in acinar cells and vascular endothelial cells in miniature pig parotid glands, which might enter blood stream and have function of endocrine secretion.

Animals ; Lacrimal Apparatus ; ultrastructure ; Male ; Mice ; Mice, Inbred Strains ; anatomy & histology ; Parotid Gland ; ultrastructure ; Pituitary Gland ; ultrastructure ; Swine ; Swine, Miniature ; anatomy & histology

Whole gland perfusion technique was applied to rat parotid glands to assess whether amylase affects fluid secretion. Control perfusion without any secretagogue evoked no spontaneous secretion. Carbachol (CCh 1 microM) induced both amylase and fluid secretion with distinctive kinetics. Fluid secretion occurred constantly around 60 microL/g-min, whereas amylase secretion exhibited an initial peak, followed by a rapid decrease to reach a plateau. Isoproterenol (Isop 1 microM) alone did not induce fluid secretion although it evoked amylase secretion as measured in isolated perfused acini. Addition of Isop during CCh stimulation evoked a rapid and large rise in amylase secretion accompanied by small increase in oxygen consumption. Morphological observations carried out by HR SEM and TEM revealed exocytotic profiles following Isop stimulation. CCh stimulation alone seldom showed exocytotic profiles, suggesting a low incidence of amylase secretion during copious fluid secretion. Combined stimulation of CCh and Isop induced both vacuolation and exocytosis along intercellular canaliculi. These findings suggest that control of salivary fluid secretion is independent of the amylase secretion system induced by CCh and/or Isop.
Amylases/metabolism* ; Animal ; Carbachol/pharmacology ; Cholinergic Agonists/pharmacology ; In Vitro ; Isoproterenol/pharmacology ; Male ; Microscopy, Electron ; Microscopy, Electron, Scanning ; Oxygen Consumption/physiology ; Oxygen Consumption/drug effects ; Parotid Gland/ultrastructure ; Parotid Gland/secretion* ; Parotid Gland/enzymology* ; Perfusion ; Rats ; Rats, Wistar ; Saliva/metabolism* ; Sympathomimetics/pharmacology