Physical complaints, such as pain, can be effectively reduced by placebo effects through induction of positive expectations, or increased by nocebo effects through induction of negative expectations. In the present study, verbally induced nocebo and placebo effects on itch were experimentally investigated for the first time. In part 1, the role of verbal suggestions in inducing nocebo effects o...

restraint-induced stress (rs) increases histamine concentration in the brain. there is no previous report regarding the role of histamine receptors in immunomodulatory effect of rs. in the present study the role of brain histamine receptors on reduction of humoral and cellular immune function induced by rs was evaluated. for this purpose male wistar rats (200-250 g) were immunized with sheep re...

Vasoneuroactive substances were applied through intradermal microdialysis membranes and characterized as itch- or pain-inducing in psychophysical experiments. Histamine always provoked itching and rarely pain, capsaicin always pain but never itching. Prostaglandin E(2) (PGE(2)) led preferentially to moderate itching. Serotonin, acetylcholine, and bradykinin induced pain more often than itching....

BACKGROUND Mast cells trigger inflammation that is associated with local pain, but the mechanisms mediating pain are unclear. Interstitial cystitis (IC) is a bladder disease that causes debilitating pelvic pain of unknown origin and without consistent inflammation, but IC symptoms correlate with elevated bladder lamina propria mast cell counts. We hypothesized that mast cells mediate pelvic pai...

Several lines of evidence suggest that brain histamine may be involved in the central control of food intake. The effect of histamine on feeding is mediated through three kinds of receptors (H1, H2, and H3). The present study was designed to investigate the effect of intracerebroventricular injection of histamine, promethazine (H1 antagonist) and ranitidine (H2 antagonist) on food intake of fre...

Recent research has proposed a pathway in which sensory neurons expressing the capsaicin activated ion channel TRPV1 are required for histamine-induced itch and subsequent scratching behavior. We examined histamine-induced itch in the African naked mole-rat (Heterocephalus glaber) and found that although naked mole-rats display innate scratching behavior, histamine was unable to evoke increased...

It has been shown that enhanced acid secretion can be suppressed in the rat by systemic administration of glucose. We have recently reported that enhancement of acid secretion as a result of pentagastrin was diminished by intragastric administration of D-glucose. Present study was designed to investigate whether intragastric D-glucose influences gastric acid secretion associated with carbachol ...

Several lines of evidence suggest that brain histamine may be involved in the central control of food intake. The effect of histamine on feeding is mediated through three kinds of receptors (H1, H2, and H3). The present study was designed to investigate the effect of intracerebroventricular injection of histamine, promethazine (H1 antagonist) and ranitidine (H2 antagonist) on food intake of fre...

Evidence has shown gender differences regarding the critical roles of histamine in the prevalence of asthma, anaphylaxis, and angina pectoris. Histamine depolarizes unmyelinated C-type neurons without any effects on myelinated A-type vagal ganglion neurons (VGNs) in male rats. However, little is known if VGNs from females react to histamine in a similar manner. Membrane depolarization and inwar...