Release of arachidonic acid from membrane phospholipids is receptor-mediated and might generate second messengers in neurons. We tested this idea using the simple nervous system of the marine mollusk, Aplysia californica. Aplysia neural components metabolize arachidonic acid through lipoxygenase and cyclo-oxygenase pathways. We identified 2 major lipoxygenase products, 12- and 5-hydroxyeicosate...

Vertebrate eyes are known to contain circadian clocks, but their regulatory mechanisms remain largely unknown. To address this, we used a cell line from human retinal pigment epithelium (hRPE-YC) with stable coexpression of reporters for molecular clock oscillations (Bmal1-luciferase) and intracellular Ca2+ concentrations (YC3.6). We observed concentration-dependent increases in cytosolic Ca2+ ...

The phylogenetic relationships within the Arthropoda have remained controversial for more than a century. Comparative studies on structure and development of the nervous system have contributed important arguments to this discussion. Earlier studies revealed only few similarities between the brain morphology in representatives of the Chelicerata and the Mandibulata. In the present report, we an...

The Effect of histamine and some Antihistamine in the motitlity of human semin were studid. It shows that the histamine increases sperm metility, further more H2 antihistamine crimetidine had no effect on sperm motility and classical antihistamines decreased sperm motility , where as the inhibition produced by H antihistamine could be over comed with increasing concentration of histamine. Final...

Background Neurotrophin-3 (NT-3) is produced by astrocytes, in addition to neurons, and monoamine neurotransmitters play a role in controlling NT-3 synthesis [1]. The impact of histamine on the regulation of NT-3 synthesis in cultured astrocytes has not been studied in detail. Therefore, we focused our present study on the active involvement of multiple histaminergic receptor and intracellular ...

the effects of some histaminergic agents were evaluated on stress- induced immunosuppression in immunized nale rats. in rat immunized with sheep red blood cells ( srbcs). restraint stress (rs) prevented the booster-induced rise in anti-srbc antibody titre and cell immunity response. intracerebroventicular (i.c>v) injection of histamine (150 µg/rat) induced a similar effect with rs. pretreatment...

Matsumoto I, Inoue Y, Shimada T, Matsunaga T, Aikawa T. Stimulation of brain mast cells by compound 48/80, a histamine liberator, evokes renin and vasopressin release in dogs. Am J Physiol Regul Integr Comp Physiol 294: R689–R698, 2008. First published January 9, 2008; doi:10.1152/ajpregu.00453.2007.—Because degranulation of brain mast cells activates adrenocortical secretion (41, 42), we exami...