OBJECTIVE Crocin and safranal, as the major constituents of saffron, have many biological activities. This study investigated the effects of crocin and safranal on yawning response induced by intracerebroventricular (i.c.v.) injection of histamine in rats. MATERIALS AND METHODS In ketamine/xylazine-anesthetized rats, a guide cannula was implanted in the right ventricle of the brain and yawnin...

Histamine regulates a variety of physiological processes including inflammation, gastric acid secretion, and neurotransmission. The cellular response to histamine is subject to dynamic control, and exaggerated histamine reactivity in response to cysteinyl leukotrienes and other stimuli is important in a variety of different pathological conditions. The molecular mechanisms controlling histamine...

It is well known that histamine produces constriction via H1 receptors and decreases tracheal smooth muscle tone via H2 and H3 receptors. In addition, it has already been reported that 3-methylhistamine and phenylethylamine are competitive antagonists of histamine N-methyl-transferase (HMT), the enzyme responsible for rapid inactivation of histamine. Our results suggest the possibility that 3me...

Histamine influences several immune/inflammatory and effector functions in addition to its dominant role in type I hypersensitivity reactions. Histamine can selectively recruit the major effector cells into tissue sites and affect their maturation, activation, polarization, and other functions leading to chronic inflammation. Histamine also regulates monocytes, dendritic cells, T cells and B ce...

High concentrations of codeine necessary to demonstrate histamine release frog leukocytes interfere with histamine methylation, producing a concentration-dependent flattening of the histamine standard curves obtained from single-isotope (3H) assays . For this reason, the use of uniformly labeled l4C-histamine was investigated as as internal standard . This isotope serves as as internal standard...

As a neurotransmitter or neuromodulator, brain histamine has a variety of physiological roles in brain functions such as hypothalamic- pituitary- adrenal (HPA) activity. Histamine induces the release of ACTH through the activation of hypothalamic neurons containing vasopressin and CRH. Histamine induces the activity of HPA axis directly or indirectly. Endogenous opioids modulate the (HPA) axis ...

As a neurotransmitter or neuromodulator, brain histamine has a variety of physiological roles in brain functions such as hypothalamic- pituitary- adrenal (HPA) activity. Histamine induces the release of ACTH through the activation of hypothalamic neurons containing vasopressin and CRH. Histamine induces the activity of HPA axis directly or indirectly. Endogenous opioids modulate the (HPA) axis ...

Modification of the cardiac rhythm by histamine has been appreciated almost since the compound's isolation from ergot by Barger and Dale in 1910. The major arrhythmogenic actions of histamine are an Hi-receptor-mediated slowing of atriovenrricular (AV) conduction and H2-receptor-mediated increases in sinus rate and ventricular automaticity. These actions were elucidated by observing the salutar...

human  basophils play a key role in allergic diseases such as asthma and in a variety of  immunological disorders.  the  generation  of  il-4  and  il-13  can  be  induced  from basophil  by  ige-mediated   and   non-ige-mediated   mechanisms.  time   and   stimulus- dependent  differences  in  the  regulation  of  these  cytokines  could  have  relevance  to their biological effects. the aim o...