Histochemical localization of glutamic acid dehydrogenase activity in the cuneate nucleus of the cat1

Summary Glutamic acid dehydrogenase activity was observed both in the neuropil as well as in several classes of cuneate neurons in the cat.The excellent technical assistance of Mr. C. T. Lee of our Histology Laboratory, and the support and encouragement of Professor W. C. Wong, Anatomy Department, are gratefully acknowledged.     

A comparison of ultrastructural localization of carnitine acetyltransferase activity in mouse liver mitochondria with that in cardiac muscle

Résumé En microscopie électronique l'etuee de la carnitine acétyltransférase a montré une même localisation dans les mitochondries du foie et du muscle cardiaque de souris. La grande différence d'activité que décèlent les méthodes biochimiques entre ces deux types de mitochondries peut donc être attribuée simplement à la présence 'und nombre beaucoup plus grand de crêtes dans les mitochondries du muscle cardiaque.

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Supported by grants from Medical Research Council of Canada and the Muscular Dystrophy Association of Canada.

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Dr.T. Makita is a recipient of post-doctoral fellowship from the Muscular Dystrophy Association of Canada.

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The authors wish to express their appreciation to Dr.P.-E. Messier, MissesAndrée Aubin, Cécile Venne, Heather Stephens and Mr.J.-P. Marcil for their assistance in preparation of this communication.     

Intracellular recording of electrical activity in smooth muscle of the common bile duct

Zusammenfassung Im Rahmen vergleichender Untersuchungen an verschiedenen Typen spontan aktiver glatter Muskulatur wurde beim isolierten Ductus choledochus des Meerschweinchens durch intrazelluläre Messungen des Membranpotentials regelmässig eine mittelstarke Spontanaktivität, bestehend aus sekundenrhythmischen Oszillationen mit Spikes, moduliert durch langsamere Fluktuationen im Minuten-Rhythmus, gefunden.

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This work was supported by grant No. Go 130/13 from the Deutsche Forschungsgemeinschaft.     

Intracellular localization of calcitonin in the C cells of the rat

Summary Specific localization of C cells at the electron microscope level was achieved by an indirect immunoperoxidase technique. The hormone is present in the electron dense granules. The presence of granules apparently devoid of calcitonin was also detected.We thank Miss Nicole Mendoza for her technical collaboration.     

Intracellular localization of calcitonin in the C cells of the rat.

Specific localization of C cells at the electron microscope level was achieved by an indirect immunoperoxidase technique. The hormone is present in the electron dense granules. The presence of granules apparently devoid of calcitonin was also detected.     

Intracellular localization of glutamine-aminohydrolase in normal and malignant tissues

Résumé On a comparé l'activité de la glutamineaminohydrolase dans les fractions de divers tissus cellulaires de souris normales avec celles des tissus à partir de souris ayant des tumeurs. On a constaté cette activité surtout dans la fraction surnageante des tissus de l'hôte, tandis que dans les tissues des animaux normaux elle se manifeste en majeure partie dans la mitochondrie. Dans les tissus même de la tumeur, toute l'activité est limitée à la fraction surnageante.

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Acknowledgment. The authors are thankful to Dr.A. G. Dutta for his valuable suggestions and discussions.     

Effect of the inhibition of "NADH-diaphorase" activity on the ultrastructural localization of 3 beta-hydroxysteroid dehydrogenase]

The NADH-ferricyanide oxidoreductase ("NADH-diaphorase") activity can be inhibited selectively with 0.5 mM p-chloromercuribenzoate, and the reduction of the potassium ferricyanide can be restored with an exogenous electron carrier (PMS). These operations do not affect the localization of the final precipitate of copper ferrocyanide which results from 3beta-hydroxysteroid dehydrogenase activity.     

The effect of anoxia and of muscle activity on the lymphatic and venous transport of lactate dehydrogenase

Zusammenfassung Nach 3 1/2 stündiger Muskelischämie wurde bei Hunden mit Ductus thoracicus-Fistel eine signifikante Zunahme der Milchsäuredehydrogenase-Aktivität im Blutserum und in der Lymphe der anoxischen Extremität bei gleichzeitiger signifikanter arterovenöser Aktivitätsdifferenz beobachtet. Auch Muskelarbeit verursachte eine Erhöhung der Enzymaktivität im Serum und in der Lymphe. Durch Unterbrechen der Verbindung zwischen Venen und Lymphsystem konnte das direkte Eindringen des Enzymproteins in die Blutkapillaren bewiesen werden.     

Variation in the lactase dehydrogenase activity of the esophagus

Quantitative assay and electrophoretic study of lactate dehydrogenase (LDH) from various tissues of the opossum esophagus were performed. On the basis of expression of the LDH isozymes, we concluded that the smooth muscle of the body of the esophagus carry on more anaerobic glycolysis than the striated muscle. The smooth muscle of the gastroesophageal junction carry on both anaerobic as well aerobic glycolysis.     

Variation in the lactase dehydrogenase activity of the esophagus

Summary Quantitative assay and electrophroetic study of lactate dehydrogenase (LDH) from various tissues of the opossum esophagus were performed. On the basis of expression of the LDH isozymes, we concluded that the smooth muscle of the body of the esophagus carry on more anaerobic glycolysis than the striated muscle. The smooth muscle of the gastroesophageal junction carry on both anaerobic as well aerobic glycolysis.Acknowledgments. This work was supported by Kelsey-Leary Foundation grant No. 962, Houston, Texas. We appreciate the technical assistance of Henry D. Kasten, and Carol K. Kitson.