Gastrin: Obligatory intermediate in the postprandial mobilization of gastric histamine in the rat

Summary In unoperated fasted rats, feeding raised the serum gastrin concentration, reduced the gastric mucosal histamine content and activated the gastric histidine decarboxylase. The reduction of gastric histamine and activation of histidine decarboxylase was induced also by the injection of pentagastrin. In antrectomized rats, feeding failed to produce these effects. Injection of pentagastrin, however, still lowered gastric histamine and activated gastric histidine decarboxylase. Thus, antral gastrin seems to be an obligatory mediator of the postprandial activation of histidine decarboxylase and mobilization of histamine.Acknowledgments. Grant support from the Swedish and Danish Medical Research Councils (14P-4822, 04X-1007, 17X-4144 and 512-2540).     

Action of toxins isolated from scorpion and sea anemone venoms on ileum isolated from reserpine-treated guinea pigs]

We have shown that the ileum isolated from a reserpinized guinea Pig does respond to toxin II obtained from Scorpion venom but does not react to Anemonia sulcata toxin. We conclude that if Acetylcholine is the neurotransmitter inducing pharmacological activity of Scorpion toxin it is serotonin which triggers activity of Anemonia sulcata toxin in ileum of a normal guinea Pig.     

Effect of daminozide on tomato fruit ripening

Summary Fruits of tomato (Lycopersicon esculentum Mill. cv. Fireball) were harvested 32 and 37 days after anthesis and dipped for 30 min in 10,000 ppm daminozide. Ripening of treated fruits, as manifested by an advancement in ethylene production and the respiratory climacteric, was accelerated by up to 7 days over control fruit.Acknowledgment. This investigation was supported by Agriculture Canada and the Ontario Ministry of Agriculture and Food.     

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.     

The effects of cocaine in the production of cardiovascular anomalies inβ-Adrenoreceptor stimulated chick embryos

Summary Cocaine potentiates the effects of epinephrine and norepinephrine in terms of aortic arch malformation in embryonic chicks. Cocaine itself induces aortic arch malformations when administered in large doses.This study was supported by grant No. HL 18050, National Heart and Lung Institute, National Institutes of Health, Bethesda, Maryland.     

Acid and alkaline phosphatase heterogeneity in liver,heart and intestine of the adult chick

Summary The molecular heterogeneity of acid and alkaline phosphatase from chick liver, intestine and heart is demonstrated by polyacrilamide disc gel electrophoresis. Liver and heart show the same number of molecular forms of acid and alkaline phosphatases. In contrast, the intestine homogenate shows electrophoretic bands different in number and in gel position from those of the liver and of the heart.     

Different salt concentration requirement of nuclear and cytoplasmic Mn++-stimulated poly(A) synthetase activities from rat liver

Summary Mn⁺⁺-stimulated poly(A) synthetase activity of dialyzed ammonium sulfate fraction (0–50% saturation) of nuclear extracts from rat liver is dependent on salt addition to the incubation mixture. The corresponding soluble cytoplasmic activity is inhibited by the salt concentration required for nuclear activity.     

Effects of Tabermanthe iboga H. Bn. alkaloids on the isolated organ responses to catecholamines and the role of calcium exchanges. Tabernanthine]

Using isolated Rat duodenum previously decalcified, the authors have investigated the effect of tabernanthine on the increase of tonus brought about by addition of calcium ions at different concentrations. The observed potentiating effect of tabernanthine towards the calcium responses may be pointed out concerning the mechanism of sensitizing effect of this alkaloid on the responses of isolated organs to catecholamines such as noradrenaline and dopamine.