Demilune cells of the cat submandibular gland; an unlikely source of kallikrein

The functional significance of kallikrein in the salivary gland remains unclear partially because of uncertainty over its precise cellular localization. Kallikrein was thought to originate in acinar cells, until recent evidence from cat and rat localized it primarily to the ducts. The possibility that salivary kallikrein may also be located in demilune cells was investigated in this study. - The total kallikrein content of cat submandibular glands was found to be substantially reduced by sampathetic nerve stimulation; whereas parasympathetic stimulation had no significant effect. These biochemical findings did not correlate with morphological studies that revealed almost complete depletion of the demilune cells secretory granules after stimulation of either division of the autonomic nerve supply. This lack of correlation makes it unlikely that kallikrein is present in the demilune cell secretory granules.     

Effect of nerve stimulation,denervation, and duct ligation,on kallikrein content and duct cell granules of the cat's submandibular gland

Summary Various procedures which reduce or deplete the kallikrein content of the cat's submandibular gland correspondingly reduce the number of apical granules in the striated duct cells. The kallikrein content is greatly reduced after chronic parasympathetic but not after sympathetic nerve section which suggests that the parasympathetic innervation is required for synthesis or storage of this enzyme.We wish to acknowledge the valuable assistance of Dr T. Nihei and Mr. J. Wimal in some of the enzyme measurements.This work was supported by grants from the Medical Research Council of Canada and the Alberta Heart Foundation.     

The effect of a bradykinin antagonist on vasodilator responses with particular reference to the submandibular gland of the cat

A bradykinin analogue, D-Arg[Hyp3, Thi5,8, D-Phe7]-Bk, antagonized the vasodilator effect of bradykinin injected close-arterially in the submandibular salivary gland of the cat, without affecting that due to acetylcholine or nerve stimulation. The same analogue also antagonized the hypotensive response to bradykinin injected intravenously in cats and rabbits. We conclude that functional hyperaemia in the submandibular gland of the cat is not due to the release of bradykinin by salivary kallikrein.     

Demilune cells of the cat submandibular gland; an unlikely source of kallikrein

Summary The functional significance of kallikrein in the salivary gland remains unclear partially because of uncertainty over its precise cellular localization. Kallikrein was thought to originate in acinar cells, until recent evidence from cat and rat localized it primarily to the ducts. The possibility that salivary kallikrein may also be located in demilune cells was investigated in this study. — The total kallikrein content of cat submandibular glands was found to be substantially reduced by sampathetic nerve stimulation; whereas parasympathetic stimulation had no significant effect. These biochemical findings did not correlate with morphological studies that revealed almost complete depletion of the demilune cells secretory granules after stimulation of either division of the autonomic nerve supply. This lack of correlation makes it unlikely that kallikrein is present in the demilune cell secretory granules.Acknowledgment. This study is made possible through the Dean's MRC grant number MD-3489 to the College of Dentistry, University of Saskatchewan.Authors wish to thank Mr. D. Duncan, Dept. of Oral Biology and D. Mandeville of Medical Photographic Services for technical assistance.     

The effect of a bradykinin antagonist on vasodilator responses with particular reference to the submandibular gland of the cat

Summary A bradykinin analogue, D-Arg[Hyp³, Thi^{5, 8}, D-Phe⁷]-Bk, antagonized the vasodilator effect of bradykinin injected close-arterially in the submandibular salivary gland of the cat, without affecting that due to acetylcholine or nerve stimulation. The same analogue also antagonized the hypotensive response to bradykinin injected intravenously in cats and rabbits. We conclude that functional hyperaemia in the submandibular gland of the cat is not due to the release of bradykinin by salivary kallikrein.     

Exogenous melatonin: morphology and kallikrein activity of male Syrian hamster submandibular gland

Seven weeks of daily melatonin administration resulted in substantial reduction of convoluted duct cell granule population and kallikrein activity. Some reduction of intercalated duct cell granules was also observed. Testes weight and size was also dramatically reduced. All these changes were not observed after three weeks of melatonin injection.     

Localization of renal kallikrein in the dog

Summary Renal kallikrein was estimated in glomerular, tubular and medullary fractions of dog kidneys. It was found primarily in the cortex, the highest level of activity being detected in a glomeruli-rich fraction. These results support previous observation that kallikrein may be associated with the juxta-glomerular complex.     

Localization of renal kallikrein in the dog

Renal kallikrein was estimated in glomerular, tubular and medullary fractions of dog kidneys. It was found primarily in the cortex, the highest level of activity being detected in glomeruli-rich fraction. These results support previous observation that kallikrein may be associated with the juxta-glomerular complex.     

The activity of sorbitol dehydrogenase in some mammalian erythrocytes

Summary The activity of sorbitol dehydrogenase was found to be high in the red blood cells of man, dog, guinea-pig and mouse and comparatively lower in those of goat, sheep, rabbit, cat and rat.     

Creatine phosphate inhibition of heart 5'-nucleotidase appears due to contaminants

Creatine phosphate does not inhibit 5'-nucleotidase preparations from rat, dog or guinea-pig hearts. Previously reported inhibitory effects must have been due to contaminants present in some commercial preparations of creatine phosphate.     

Effects of inhibition and stimulation of Na+-K+ active transport on the resting membrane input conductance of the guinea-pig ventricle

The effects of inhibition by ouabain and stimulation by high frequency drive of the sarcolemmal Na+-K+ active transport system on the resting input conductance (gi) of guinea-pig ventricular muscles were determined. Although both pump inhibition and stimulation were associated with changes in electrophysiological properties of the muscles, neither had a significant effect on gi.     

Formation of intracellular canaliculi in reaggregated striated duct cells of rat submandibular gland during short-term stationary culture

Reaggregated striated duct cells of rat submandibular gland formed deep tubular invaginations of the cell membrane, i.e. intracellular canaliculi, which are not present in the original tissue, after 24 h of the stationary culture.     

Action de l'acide acétylsalicylique sur le système nerveux végétatif

Summary Our experiments, made possible by the utilisation of the injectable acetyl-salicylate lysine salt solution, lead us to conclude that acetyl-salicylique acid has a parasympathicomimetic action on the pupil of the mice, on the intestine of the dog and on the bronchi of the guinea-pig.     

Neuropeptide Y in the guinea-pig biliary tract

High concentrations of neuropeptide Y (NPY) have been demonstrated in the gall bladder (16.7 +/- 5.4 pmol/g), cystic duct (25.4 +/- 9.2 pmol/g) and common bile duct (54.7 +/- 11.5 pmol/g) of the guinea-pig using a recently developed radioimmunoassay. Immunoreactive NPY containing nerves were demonstrated in all layers of the biliary tree using immunocytochemistry, being particularly dense in the myenteric and mucosal plexuses.     

Normal liver actually possesses a high vascular plasminogen activator activity.

Blood vessels isolated from the liver of the rat, guinea-pig, rabbit, dog and pig showed histochemically a more or less high plasminogen activator activity. In whole liver sections, the abundant release and diffusion of inhibitors of fibrinolysis from the liver parenchyma during the histochemical procedure, partially or totally mask this high vascular activity.     

Normal liver actually possesses a high vascular plasminogen activator activity

Summary Blood vessels isolated from the liver of the rat, guinea-pig, rabbit, dog and pig showed histochemically a more or less high plasminogen activator activity. In whole liver sections, the abundant release and diffusion of inhibitors of fibrinolysis from the liver parenchyma during the histochemical procedure, partially or totally mask this high vascular activity.     

Effect of (+)-catechin on renal and intestinal transport.

The ability of dog renal cortex slices to accumulate beta-methyl-glucoside or glycine is enhanced by the flavonoid (+)-catechin at a concentration of 3.5 mM. This stimulatory effect is apparently due to a decreased rate of efflux of either substrate. On the other hand, the uptake of p-amino-hippuric acid and N1-methyl-nicotinamide is inhibited by (+)-catechin. The drug at the same concentration is without action on amino-acid transport by guinea-pig intestine in vitro.     

Effects of inhibition and stimulation of Na+−K+ active transport on the resting membrane input conductance of the guinea-pig ventricle

Summary The effects of inhibition by ouabain and stimulation by high frequency drive of the sarcolemmal Na⁺–K⁺ active transport system on the resting input conductance (g_i) of guinea-pig ventricular muscles were determined. Although both pump inhibition and stimulation were associated with changes in electrophysiological properties of the muscles, neither had a significant effect on g_i.Supported by a grant from the North Carolina Heart Association.     

Die Urokinase des Meerschweinchens

Summary In contrast to the urinary fibrinolysokinase (=urokinase) of other species, the urokinase in guineapigs reveals a most peculiar behaviour. A significant and well reproducible activation of fibrinolysin is obtainable only when guinea-pig fibrinolysin is used. Fibrinolysin of other species is only slightly activated. This fact is most important in investigations on the increased fibrinolytic activity of guinea-pig urine.     

Contraction of myoepithelial cells in secreting submandibular glands of dogs.

In slowly secreting submandibular glands of dogs, a sympathetic effect on myoepithelial cells was demonstrated as an acceleration of the flow, followed by retardation, on short-lasting sympathetic stimulation, particularly after beta-adrenoceptor-blocking drugs.