We prepared a model of experimental peritonitis by introducing Escherichia coli into the peritoneal cavity of the histamine-deficient mice generated by a disruption of the gene for histidine decarboxylase (HDC), the unique histamine-synthesizing enzyme. When we inoculated E. coli into the peritoneal cavities of the HDC(-/-) (histamine-deficient) mice, they eliminated E. coli more efficiently th...

We have previously demonstrated that dietary histamine is accumulated in the spleens of l-histidine decarboxylase (HDC)-deficient mice, which lack endogenous histamine synthesis. To characterize the clearance system for dietary histamine in mice, we investigated the cell type and mechanism responsible for histamine uptake in the spleens of HDC-deficient mice. Immunohistochemical analyses using ...

OBJECTIVE The nucleus accumbens (NAc) receive histaminergic neurons from tuberomammillary nuclei. There are reports indicating that central histamine systems are involved in many physiological behavioral processes, including anxiety. The aim of the present study was to assess whether the histaminergic system of the NAc is involved in anxiety-related behaviors. METHODS Rats were anesthetized w...

The present study in the wall lizard, Hemidactylus flaviviridis, was aimed to understand the role of histamine (HA) in the regulation of Leydig cell and testicular macrophage activities, for the first time, in ectothermic vertebrates. Although HA did not affect the testosterone production from unstimulated Leydig cells, it had dual concentration-related effects, stimulatory at a low concentrati...

INTRODUCTION There are many common drugs which have significant sedative-hypnotic properties. Alcohol and barbiturates have been discussed separately in this appendix, and their many pharmacological similarities were indicated. Barbiturates are often considered the prototype of sedative-hypnotic drugs; pharmacologically related compounds are frequently identified or discussed in terms of their ...

IV-ethylmaleimide (NEM), an alkylating agent that covalently binds sulfhydryl groups, and dithiothreitol (DTT, Cleland's reagent), which reduces disulfide bridges to sulfhydryl groups, affected drug-induced contractions of rabbit aorta. NEM depressed aortic responses to potassium chloride (KC1), norepinephrine, serotonin, histamine, and angiotensin II. This action was attributed to an interacti...

Atypical antipsychotics such as clozapine and olanzapine have been shown to enhance histamine turnover and this effect has been hypothesized to contribute to their improved therapeutic profile compared to typical antipsychotics. In the present study, we examined the effects of antipsychotic drugs on histamine (HA) efflux in the mPFC of the rat by means of in vivo microdialysis and sought to dif...

Acute ultraviolet light B (UVB) injury is associated with dermal mast cell histamine release. The possibility that histamine-stimulated prostaglandin (PG) synthesis could be a mechanism for irradiation erythema was therefore examined using human skin explants. Explants responded to UV irradiation (120 mJ/cm2) with a fivefold increase in synthesis of prostaglandins E2, F2 alpha and 6-keto PGF1 a...

Retinal pigment epithelial (RPE) cells transport a variety of solutes, but the capacity of human RPE cells to transport drugs and xenobiotics is not well understood. As an initial step to address this issue, we have examined human RPE transport of verapamil. Transport of [3H]verapamil was measured in two human RPE cell lines (RPE/Hu and ARPE-19) grown to confluence on 12-well culture plates. Ve...

The peach tree, Prunus persica (L.) Batsch, is widely cultivated in China, and its flowers have been used for centuries in traditional Chinese medicine to treat gut motility disorders. But few studies have explored the pharmacological effect of Prunus persica (L.) Batsch flowers on gastrointestinal motility. In this study, the activities of different extracts from Prunus persica (L.) Batsch flo...