Biomaterial Database

Effects of H1 and H2 receptor antagonists on Tetrahymena. 1978

G Csaba, and V László, and Z Darvas

In Tetrahymena pyriformis the phagocytotic rate increases in response to histamine, but neither the H1 antagonist phenindamine nor the H2 antagonist metiamide stimulate phagocytosis. The H1 antagonist counteracts the effect of histamine, whereas the H2 antagonist does not. The histamine receptor of Tetrahymena is of H1-type, since it cannot distinguish between histamine and antagonists which are closely related to it chemically. It does, however, distinguish between histamine and the chemically unrelated H1 antagonist, phenindamine. The H2 antagonist does not interact with the receptor.

UI	MeSH Term	Description	Entries
D007192	Indenes	A family of fused-ring hydrocarbons isolated from coal tar that act as intermediates in various chemical reactions and are used in the production of coumarone-indene resins.
D008785	Metiamide	A histamine H2 receptor antagonist that is used as an anti-ulcer agent.	Metiamide Monohydrochloride,SK&F-92058,SKF-92058,Monohydrochloride, Metiamide,SK&F 92058,SK&F92058,SKF 92058,SKF92058
D010587	Phagocytosis	The engulfing and degradation of microorganisms; other cells that are dead, dying, or pathogenic; and foreign particles by phagocytic cells (PHAGOCYTES).	Phagocytoses
D011725	Pyridines	Compounds with a six membered aromatic ring containing NITROGEN. The saturated version is PIPERIDINES.
D011969	Receptors, Histamine H1	A class of histamine receptors discriminated by their pharmacology and mode of action. Most histamine H1 receptors operate through the inositol phosphate/diacylglycerol second messenger system. Among the many responses mediated by these receptors are smooth muscle contraction, increased vascular permeability, hormone release, and cerebral glyconeogenesis. (From Biochem Soc Trans 1992 Feb;20(1):122-5)	H1 Receptor,Histamine H1 Receptors,H1 Receptors,Histamine H1 Receptor,Receptors, H1,H1 Receptor, Histamine,H1 Receptors, Histamine,Receptor, H1,Receptor, Histamine H1
D011970	Receptors, Histamine H2	A class of histamine receptors discriminated by their pharmacology and mode of action. Histamine H2 receptors act via G-proteins to stimulate ADENYLYL CYCLASES. Among the many responses mediated by these receptors are gastric acid secretion, smooth muscle relaxation, inotropic and chronotropic effects on heart muscle, and inhibition of lymphocyte function. (From Biochem Soc Trans 1992 Feb;20(1):122-5)	Histamine H2 Receptors,H2 Receptors,Receptors, H2,H2 Receptors, Histamine
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013769	Tetrahymena pyriformis	A species of ciliate protozoa used extensively in genetic research.	Tetrahymena pyriformi,pyriformi, Tetrahymena
D013890	Thiourea	A photographic fixative used also in the manufacture of resins. According to the Fourth Annual Report on Carcinogens (NTP 85-002, 1985), this substance may reasonably be anticipated to be a carcinogen (Merck Index, 9th ed). Many of its derivatives are ANTITHYROID AGENTS and/or FREE RADICAL SCAVENGERS.