The release of histamine by d-tubocurarine from the isolated diaphragm of the rat

Release of tissue histamine by the babesicidal agents quinuronium and amicarbalide

Quinuronium sulphate liberated appreciable quantities of histamine from tissues of mice, rats and sheep. The signs of quinuronium poisoning in mice and rats were more severe than for compound 48/80. The animals acquired tolerance to the latter drug. Thus the toxicity of quinuronium probably depended on factors other than histamine release. Amicarbalide released amounts of histamine comparable with those liberated by quinuronium only in rat tissues.

RELEASE OF HISTAMINE AND 5-HYDROXYTRYPTAMINE FROM CELLS OF THE PERITONEAL FLUID OF RATS

Cell suspensions from the peritoneal cavity of rats are suitable preparations for the study of the release of physiologically active substances. The mast cells in these suspensions contain most of the histamine and 5-hydroxytryptamine, and all the extractable heparin. When subjected to incubation in the presence of base-type histamine liberators, lytic substances, dilution with distilled water, or freezing and thawing, histamine and 5-hydroxytryptamine are quantitatively released. The release of histamine and 5-hydroxytryptamine by histamine liberators is pH- and temperature-dependent. The release of these amines by procedures not involving the rupture of primary chemical bonds provides evidence that both amines are enclosed in a diffusible form or loosely bound, within the cell structure.

Histamine release and pain production by xanthosine and related compounds

Xanthosine (5 to 50 mug.) caused pain on intradermal injection in all human subjects tested: in about half the subjects it also gave a flare. Inosinic acid, uric acid, allantoin, alloxan and theophylline caused pain, but not a flare by intradermal injection in man. Xanthine caused both pain and flare. A number of related compounds in similar doses caused neither pain nor flare. Inosine, inosinic acid, and guanosine, but not xanthosine, were powerful histamine liberators in animals. The lowering of the cat blood pressure, depression of the activity of the guinea-pig ileum and stimulation of guinea-pig uterus by adenosine were confirmed.

Effect of chain length of aliphatic amines on histamine potentiation and release

Diamines in the series NH(2).(CH(2))(n).NH(2) specifically potentiate histamine contractions of the guinea-pig ileum and inhibit the enzymatic destruction of histamine. These activities are greatest with short-chain compounds (n approximately 5). Diamines also release histamine from isolated tissues and depress the contractility of plain muscle and the motility of paramecia. These activities increase with chain-length and are probably limited only by solubility. The parallelism between histamine-releasing activity and toxicity also extends to the monoamines in the series CH(3).(CH(2))(n-1).NH(2). Histamine-releasing activity of both series increases with increase of pH and can mainly be attributed to the non-ionized base.From the results on the effect of chain-length and ionization on activity, it is suggested that aliphatic amines release histamine by penetration of the cell membrane in the non-ionized form, followed by exchange in the ionic form with intracellular histamine.

Activation of profibrinolysin by antigen-antibody reaction and by anaphylactoid agents; its relation to complement

The activation of profibrinolysin in sensitized guinea pig serum when mixed in vitro with the homologous antigen was confirmed with a more accurate and more reliable method than the one previously used. A study was made of some of the conditions required for obtaining maximum activation. Profibrinolysin activation was also induced in normal guinea pig serum by addition of certain "anaphylactoid" agents such as peptone, tween 20, morphine, octylamine, octadecylamine, and 48/80. The specific antigen and the anaphylactoid agents produce activation only when added to whole, fresh, unheated serum. Profibrinolysin activation by these agents, as opposed to activation by streptokinase, seems to require the intervention of a kinase system (serofibrinokinase) inactivated by fractionation of serum and by heating to 56 degrees C. Whenever serum was submitted to treatments which caused fractionation, fixation or inhibition of complement, serofibrinokinase was also inactivated. Under the conditions investigated the behavior of this kinase was indistinguishable from that of complement.

The pharmacological properties of "laudolissin" a long-acting curarizing agent

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