Biomaterial Database

Selective enhancement of histamine H1-receptor responses in guinea-pig ileal smooth muscle by 1,4-dithiothreitol. 1986

J Donaldson, and S J Hill

1,4-Dithiothreitol (DTT; 1 mM, 30 min preincubation) produced a small, non-specific potentiation of spasmogenic activity in longitudinal muscle strips of guinea-pig small intestine. A direct comparison of contractile responses elicited by histamine and a range of H1- and non-H1-receptor agonists indicated that DTT produced a significantly greater potentiation of H1-receptor responses. This apparently selective increase in tissue sensitivity to histamine H1-receptor agonists did not appear to be a consequence of the inhibition of histamine N-methyl transferase or diamine oxidase activity. Potentiation of the responses to histamine by DTT was still observed in the presence of SKF 91488 (10 microM) and aminoguanidine (1 microM). The potentiation elicited by DTT was readily reversed by the sulphydryl oxidizing agent dithiobis-(2-nitrobenzoic acid) (DTNB). This suggests that the mechanism of action of DTT involves the reduction of disulphide bonds. Exposure of ileal smooth muscle to DTT following desensitization with histamine (100 X EC50 [- DTT]) resulted in a 6.9 +/- 0.7 fold shift of the concentration-response curve to lower agonist concentrations. Conversely, following potentiation of the response to histamine with DTT, exposure of the tissue to desensitizing concentrations of histamine resulted in a dextral shift of the dose-response curve (dose ratio = 39.5 +/- 1.2) to higher agonist concentrations. The results of this study suggest that DTT may be a useful tool with which to investigate histamine H1-receptor mechanisms in ileal smooth muscle.

UI	MeSH Term	Description	Entries
D007082	Ileum	The distal and narrowest portion of the SMALL INTESTINE, between the JEJUNUM and the ILEOCECAL VALVE of the LARGE INTESTINE.
D008297	Male		Males
D009119	Muscle Contraction	A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.	Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D009130	Muscle, Smooth	Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)	Muscle, Involuntary,Smooth Muscle,Involuntary Muscle,Involuntary Muscles,Muscles, Involuntary,Muscles, Smooth,Smooth Muscles
D011725	Pyridines	Compounds with a six membered aromatic ring containing NITROGEN. The saturated version is PIPERIDINES.
D011738	Pyrilamine	A histamine H1 antagonist. It has mild hypnotic properties and some local anesthetic action and is used for allergies (including skin eruptions) both parenterally and locally. It is a common ingredient of cold remedies.	Mepyramine,Pyranisamine,Anthisan,Boots Bite & Sting Relief,Kriptin,Mepyramine Maleate,Pyrilamine Maleate,Maleate, Mepyramine,Maleate, Pyrilamine
D011968	Receptors, Histamine	Cell-surface proteins that bind histamine and trigger intracellular changes influencing the behavior of cells. Histamine receptors are widespread in the central nervous system and in peripheral tissues. Three types have been recognized and designated H1, H2, and H3. They differ in pharmacology, distribution, and mode of action.	Histamine Binding Sites,Histamine Receptors,Histamine Receptor,Binding Sites, Histamine,Receptor, Histamine,Sites, Histamine Binding
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
D004228	Dithionitrobenzoic Acid	A standard reagent for the determination of reactive sulfhydryl groups by absorbance measurements. It is used primarily for the determination of sulfhydryl and disulfide groups in proteins. The color produced is due to the formation of a thio anion, 3-carboxyl-4-nitrothiophenolate.	5,5'-Dithiobis(2-nitrobenzoic Acid),DTNB,Ellman's Reagent,5,5'-Dithiobis(nitrobenzoate),Acid, Dithionitrobenzoic,Ellman Reagent,Ellmans Reagent,Reagent, Ellman's
D004229	Dithiothreitol	A reagent commonly used in biochemical studies as a protective agent to prevent the oxidation of SH (thiol) groups and for reducing disulphides to dithiols.	Cleland Reagent,Cleland's Reagent,Sputolysin,Clelands Reagent,Reagent, Cleland,Reagent, Cleland's