Alpha-chymotrypsin (CT) was modified chemically and physically by the treatments with diisopropyl fluorophosphate, L-(1-tosylamide-2-phenyl) ethylchloromethylketone, hydrogen peroxide and heat. After these treatments, CT lost or decreased both the enzymic activity and ability of releasing histamine from rat mast cells. Ca++ was essential for histamine release by CT, while it enhanced only sligh...

Dithranol is a potent agent in treating psoriasis but its adverse effects on intact skin have limited its usage. There are many proposed mediators for its adverse effects including prostaglandins, histamine, platelet activating factor and free radicals. In this study we examined the effect of different agents (diazepam, terfenadine, indomethacin and garlic extract) on dithranol-induced skin dam...

JOHNSON, ALICE R., AND NEIL C. MORAN. Selective release of histamine from rat mast cells by compound 48/80 and antigen. Am. J. Physiol. 216(3) : 453-459. 1969.-To test the hypothesis that rat mast cells are not disrupted by the action of histamine-releasing agents such as compound 48/80 and antigen, suspensions of mast cells were treated with these agents and the release of histamine and other ...

JOHNSON, ALICE R., AND NEIL C. MORAN. Selective release of histamine from rat mast cells by compound 48/80 and antigen. Am. J. Physiol. 216(3) : 453-459. 1969.-To test the hypothesis that rat mast cells are not disrupted by the action of histamine-releasing agents such as compound 48/80 and antigen, suspensions of mast cells were treated with these agents and the release of histamine and other ...

Pruritus is an individual unpleasant sensation of human sensory nervous system. In the physiological condition it excerts a self-protective mechanism to protect the skin against external harmful agents. Pruritoceptive itch is also a major symptom of skin diseases and a common reason for consulting a dermatologist in clinic. It has been well known that both histamine-dependent and histamine-inde...

We examined ZO-1 protein content in cultured retinal vascular endothelial cells to test the hypothesis that histamine alters tight-junction-protein expression. Histamine (10(-9) -10(-4) M) causes a reversible concentration-dependent reduction of ZO-1 protein content, mediated by both H1 and H2 receptors. Histamine reduces ZO-1 expression within the time associated with increased paracellular pe...

Prostaglandin E(1) lowers the threshold of human skin to histamine-evoked itching. Though histamine and other mediators may produce itching by a direct action, itching in inflamed skin can also be explained by a pharmacological synergism in which low concentrations of prostaglandins, which do not themselves cause itching, potentiate itching due to histamine and possibly other agents. Alteration...

Basophils possess membrane bound IgE molecules, and immunological activation leads to a secretary process with cell degranulation and histamine release. Heterologous anti IgE, concanavaline A, and phytohaemagglutinin are potent non-cytotoxic releasing agents. They operate by a mechanism similar to that ofimmunological activation. Heavy water is not a histamine releasing inducer but it increases...

Basophils possess membrane bound IgE molecules, and immunological activation leads to a secretory process with cell degranulation and histamine release. Heterologous anti IgE, concanavaline A, and phytohaemagglutinin are potent non-cytotoxic releasing agents. They operate by a mechanism similar to that of immunological activation. Heavy water is not a histamine releasing inducer but it increase...

Histamine release caused by drugs and/or their solvents is a well known phenomenon. In this study, both in vivo (anaesthetized and conscious dogs) and in vitro (isolated rat peritoneal, human and guinea-pig lung mast cells) models were used. Cremophor E1 and six derivatives of 12-hydroxystearic acid were compared for their histamine releasing abilities. Although the three types of isolated mast...