Inhibition of immediate hypersensitivity responses in flatfish

Résumé Comme le cromoglycate disodique et la diéthylcarbamazine (qui ne sont pas des antistaminiques) inhibent la réaction d'hypersensibilité immédiate chezPleuronectes platessa à la suite d'une injection intradermique d'extraits fungiques, il semble que les médiateurs autres que l'histamine peuvent être impliqués.     

Inhibition and enhancement of photically evoked responses by different doses ofl-DOPA

Summary Administration of small doses ofl-DOPA (10 and 20 mg/kg) resulted in reduction in amplitude of photically evoked responses in the primary visual, association, and cerebellar vermal cortices, while large doses (40 and 80 mg/kg) produced enhancement.Acknowledgment. We thank Prof.K. Kuriyama and Sr.M. McCormick for their help.     

Respiratory responses in heat-exposed rabbits: Inhibition of tachypnoea offset by increase in tidal volume

Summary Rabbits in which thermal panting has been inhibiting by previous cold exposure or by water deprivation respond to a raised ambient temperature with an increase in tidal volume. By so doing, they are able to maintain a minute volume appropriate to their thermoregulatory requirements.     

An alkaline protease in the delayed hypersensitivity skin lesions in the guinea-pigs.

An alkaline hemoglobinolytic protease was extracted from the delayed hypersensitivity skin lesions induced by bovine gamma-globulin as an antigen in the guinea-pig. The enzyme was heat-labile and inhibited by thiol-blocking reagents. The mol.wt. was more than 100,000 and optimal pH around 9.     

Inhibition of fading in fluorescence microscopy of fixed cells.

Following Hirschfeld et al., dithionite was added to mounting media to inhibit fluorescence fading. Excellent response is reported for fluorescein, acridine orange, 33258 Hoechst, acriflavine, berberine (and ethidium bromide), but not for quinacrine.     

Inhibition of saline-induced diuresis in the rat by sulpiride.

Sulpiride (120 mg/kg, i.p.) inhibited saline-induced diuresis in the rat, an effect not observed with haloperidol, clozapine, pimozide or chloromazine. The antidiuretic effect of sulpiride also occurred in hypophysectomized rats suggesting that the response was not prolactin-mediated.     

Inhibition by verapamil of ionophore-mediated calcium translocation.

Verapamil and other organic calcium-antagonists inhibit the A23187-mediated translocation of calcium from an aqueous into an organic phase.     

Inhibition of rat liver transglutaminase by nucleotides.

Tissue-type transglutaminase (TGase) was purified from rat liver, and the effects of nucleotides on its activity were examined. The enzyme activity is inhibited by ATP in a concentration-dependent way, with complete inhibition by 3 mM ATP. Partially-purified TGase from human brain was inhibited by ATP in a manner similar to that observed with the rat liver enzyme. This suggests that the inhibition is a common phenomenon for tissue-type TGase in all species and tissues. The inhibition is reversible since full activity is restored by lowering the ATP concentration. CTP has a TGase-inhibitory potency equivalent to that of ATP, whereas GTP and UTP possess about 50% of the inhibitory activity of ATP. ADP inhibits TGase activity to the same extent as ATP, but AMP causes much less inhibition, and there is no inhibition by adenosine or adenine. The inhibition by ATP is insensitive to ionic strength and is non-competitive with the substrate putrescine. Since ATP levels in cells are of mM order, these results suggest that TGase activity is controlled by ATP in vivo.     

Inhibition of protein synthesis in ischaemic liver from phenobarbitone-treated rat.

Both ribosomal factors and cytosolic inhibitors are involved in the reduction of the rate of protein synthesis which occurs in the ischaemic hepatocyte from control and phenobarbitone-treated livers. Of these 2 factors it is the latter which seems to play a major role in determining the irreversible impairment of protein synthesis. Phenobarbitone administration has no effect on the rate of protein synthesis of ischaemic and post-ischaemic hepatocyte.     

Inhibition of isoprenaline-induced increase in plasma renin concentration by vasoconstrictors.

The vasoconstrictors angiotensin II, vasopressin and the alpha-sympathomimetic phenylephrine significantly inhibit the renin release caused by the beta-sympathomimetic isoprenaline. The mechanism of the inhibition is discussed.     

An immediate effect of thyroxine in the new-born pig

Résumé Deux augmentations, l'une immédiate et l'autre latente, s'observent dans la consommation d'oxygène après injection sous-cutanée de thyroxine au porcelet nouveau-né. L'augmentation immédiate présente un maximum environ 4 h après l'injection. Elle a été la plus forte chez les porcelets de l'âge 1 à 4 journées.

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British Council Scholar on leave of absence from Institute of Animal Physiology and Nutrition, Jablonna, Warsaw.     

Induction of delayed hypersensitivity by carrageenan

Zusammenfassung Nachweis einer Sensibilisierung des Meerschweinchens durch intradermale Injektion von Carrageenan, was zu «passiv übertragbaren» Spätreaktionen führte.

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The authors wish to thank to MissI. Kawana, MissA. Saito and MissA. Chida for their technical assistance and Prof.Y. Horiuchi for his advice.