The effect of histamine on steady-state mRNA levels of three soluble secretory proteins from chromaffin granules was investigated in cultured bovine adrenal medullary cells. Histamine stimulated secretogranin I1 mRNA 4-fold, with no or only slight effects on chromogranin A and B transcription. After an initial lag phase, secretogranin I1 mRNA increased markedly between 4 and 12 h followed by a ...

cyclizine (1-benzhydryl-4-methyl-piperazine, cas 82-92-8, cyc, i), a piperazine derivative, belongs to h1 antihistamine group of drugs that shows such pharmacological properties as anti-inflammatory, anti-allergic and anti-platelet effects, similar to other h1-receptor antagonists. in this study, two new tolyl and cumene derivatives of i (1-ethyl-4-[(p-isopropylphenyl) (p-tolyl) methyl]-piperaz...

It is increasingly clear that histamine mediates a variety of lymphocyte functions. Further understanding of these mechanisms requires a method for the analysis of histamine membrane receptors on the lymphocyte surface. We report now a biochemical technique for the identification and quantitation of specific histamine H1 and H2 receptors of lymphocytes. The method can be performed on small numb...

Effects of histamine per se along with its specific agonists and antagonists were studied on the skin melanophores of Hemidactylus flaviviridis to study the role of histamine receptors in pigmentation. Histamine and 2-methyl histamine induced powerful melanin aggregation effects, leading to paling of the skin through stimulation of H1 receptors. On the other hand, 4-methyl histamine, a specific...

Histamine is an accepted neurotransmitter and/or neuromodulator in the central nervous system (CNS). Its neuronal system in the brain is well organized, with cell bodies localized in a small area of the posterior hypothalamus. Diverse biological actions of histamine are mediated via three classes of receptors termed H1, H2, and H3. The existence of other histamine receptor subtypes is likely in...