Effects of histamine (HA) and agonists of HA receptors on phosphoinositide metabolism in chick cerebral cortex have been studied using two approaches - measurement of inositol 1,4,5-trisphosphate (IP3) level by a specific and sensitive IP3 receptor radioassay, and analysis of [3H]inositol phosphates accumulation in cortical slices prelabeled with myo-[3H]inositol. HA concentration-dependently e...

1. Nicotine, 20 mug/ml, briefly and partially blocked the longitudinal contractions of a chick vagus nerve-oesophagus preparation to nerve stimulation, but potentiated them in the presence of hyoscine, 10 mug/ml.2. Strychnine, 20 mug/ml, antagonized the longitudinal contractions of the chick oesophagus to nerve stimulation, though not to acetylcholine or 5-hydroxytryptamine. Hyoscine, 10 mug/ml...

Effects of histamine (HA) on cyclic AMP production and its action upon the effects evoked by vasoactive intestinal peptide (VIP) were studied in the chick hypothalamus. HA (0.1-1000 microM) potently stimulated cyclic AMP formation in the hypothalamic slices, reaching maximal effect (2.5-3.5-fold increase) at a 100 microM concentration, and displaying an EC50 value of approximately 6.5 microM/ T...

Kujin, the dried root of Sophorae flavescensis, has been used in Chinese folklore medicine against allergy. Evaluation of its anti-allergic potential as well as its mechanism of action has rarely been established. We investigated the effect of Kujin on toluene-2,4-diisocyanate (TDI)-induced allergic behavior and related histamine signaling including mRNA levels of histamine H(1) receptor (H1R) ...

The histaminergic system is thought to regulate brain reward, but the exact mechanisms are poorly understood. This study aims to reveal the pathophysiological differences in the brain histaminergic system between selectively outbred alcohol-preferring AA and alcohol-avoiding ANA rats by using a combination of biochemical, immunohistochemical, and molecular biological methods. We also want to te...

Histamine is an inflammatory mediator present in mast cells, which are abundant in the wall of the gallbladder. We examined the electrical properties of gallbladder smooth muscle and nerve associated with histamine-induced changes in gallbladder tone. Recordings were made from gallbladder smooth muscle and neurons, and responses to histamine and receptor subtype-specific compounds were tested. ...

The effect of intra-arterial histamine on fingertip blood flow (FBF) and vascular resistance (FVR) was studied in normal subjects during reflex sympathetic vascoconstriction induced by body cooling and vasoconstriction caused by intra-arterial noradrenaline. In a room at 20 degrees C, FBF increased from 15.3 +/- 35.5 (SD) to 28.3 +/- 55.9 ml min-1 100 ml-1 of tissue and FVR decreased from 23.7 ...

picralima nitida is used traditionally for management of cough. this study, therefore, investigated the antitussive, expectorant, and analgesic properties of the ethanolic seed extract of picralima nitida (pne), and ascertained its safety for use. presence of secondary metabolites, and safety of pne (10-2000 mg/kg) were evaluated by preliminary phytochemical screening, and by irwin’s test respe...