Disease relevance of Dimaprit

• Isoliquiritigenin prominently inhibited H(2)R selective agonist dimaprit-induced cAMP generation in MKN-45 gastric cancer cell [1].
• Eosinophil chemotaxis and anterior uveitis from topical dimaprit and nordimaprit [2].
• Dimaprit administration [20 micrograms/rat, intracerebroventricularly (ICV)] to rats 2 hours before decapitation increased the number of SS receptors in the frontoparietal cortex without changing the affinity constant [3].
• Administration of 2-methyl-histamine (0.2, 0.4, 0.8, 1.0 mumol/rat, i.c.v.) and dimaprit (0.1, 0.2, 0.4, 0.8 mumol/rat, i.c.v.) also displayed dose-dependent blockade of carrageenin-induced hyperalgesia [4].
• Among the analeptic effects of dimaprit, only the protection against urethane toxicity was antagonized by metiamide [5].

High impact information on Dimaprit

• The topical injection of histamine or the H(2) agonist dimaprit rescued the defective angiogenesis and granulation tissue formation in HDC(-/-) mice [6].
• Some mice were simultaneously injected with TGFbeta1 or with the H2 receptor agonist dimaprit [7].
• CONCLUSION: Administration of TGFbeta1 or dimaprit, both of which are believed to promote the development of immunoregulatory T cells, may reinforce induction of oral tolerance, even after the onset of arthritis [7].
• When histamine and H2 agonists, such as 4-methylhistamine and dimaprit, were added to the culture medium containing murine bone marrow stromal cells, thymocyte comitogenic activity detected in the medium increased significantly [8].
• This cyclic analogue of dimaprit proved to be the most potent and selective histamine H2 receptor agonist of a series of substituted 4- or 5-(2-aminoethyl)thiazoles [9].

Chemical compound and disease context of Dimaprit

• Antiproliferative and depigmenting effects of the histamine (H2) agonist dimaprit and its derivatives on human melanoma cells [10].
• Histamine and H2-receptor agonists (dimaprit, impromidine) dose-dependently decrease the positive chronotropic and inotropic effects, and the severity of arrhythmias evoked by the challenge of sensitized hearts with specific antigen [11].
• At a dose ineffective per se, dexchlorpheniramine (10 mg/kg i.p.) antagonized the hyperalgesia induced by HTMT (40 mug/mouse i.c.v. or 10 mg/kg s.c.). Dimaprit (H(2) receptor agonist, 30 mg/kg i.p.) and ranitidine (H(2) receptor antagonist, 20 and 40 mg/kg i.p.) reduced the nociceptive responses in the early and late phases [12].
• Gastric and duodenal ulcers were induced in the rat by dimaprit (100 mg X kg-1 intravenously) and cysteamine (250 mg X kg-1 subcutaneously), respectively [13].
• Conversely, verapamil only slightly attenuates dimaprit-stimulated gastric acid secretion and exacerbates ethanol-induced gastric ulcers; its anti-stress ulcer effects are only partially attenuated by indomethacin [14].

Biological context of Dimaprit

• Topical application of the H2-histamine receptor agonist, dimaprit (S-[4-N,N-dimethylaminopropyl]isothiourea), produced eosinophil chemotaxis into the anterior segment of rabbit eyes only when an H2-antagonist was co-administered [2].
• No significant differences, however, were detected for the basal or FK-stimulated AC enzyme activity in the control, dimaprit-, and/or cimetidine-treated groups, which suggests no impairment of the AC catalytic subunit [3].
• 6. The effects of histamine on synaptic transmission and PPD were mimicked by the selective H3 receptor agonist R-alpha-methylhistamine (0.1-10 microM) but not by the selective H2 receptor agonist dimaprit (10 microM) [15].
• Histamine acted via H1 receptors to increase TOH phosphorylation; the response was blocked by the H1 antagonist mepyramine and could be mimicked by the H1 agonist thiazolylethylamine, but not by the H2 agonist dimaprit [16].
• Indeed, the entry of these progenitors into S phase that is normally promoted by dimaprit, a specific histamine H2 receptor agonist, is abolished by a preincubation with GM-CSF [17].

Anatomical context of Dimaprit

• These compounds were evaluated for antagonism of the dimaprit-stimulated chronotropic response in the guinea pig atrium and inhibition of histamine stimulated secretion of gastric acid in the dog [18].
• 3. The effects of histamine and dimaprit and the effects of cimetidine on histamine responses were also investigated in guinea-pig right ventricular papillary muscles in order to allow a comparison with human papillary muscles [19].
• Topical application of dimaprit with an H2-antagonist or nordimaprit alone may allow large numbers of non-degranulated eosinophils, free of other cell types, to be harvested from the aqueous humor [2].
• This conclusion is also consistent with the observation that dimaprit, a specific agonist of these receptors not only enhances the sensitivity of day-8 CFU-S to HU after a 2 hr incubation with bone marrow cells but also increases, to the same extent as IL-3, the number of colonies formed in irradiated spleens after a 5 hr pretreatment [20].
• The in vitro addition of dimaprit or cimetidine to frontoparietal cortex membranes from untreated rats did not markedly affect the SS binding characteristics [3].

Associations of Dimaprit with other chemical compounds

• The effect of HA was mimicked by HA H1- and H2-receptor-selective agonists in the following order of potency: HA > 4-methylhistamine (H2) > 2-methylhistamine (H1) > 2-thiazolylethylamine (H1) >> dimaprit (H2) [21].
• SK&F 93319 inhibited depressor responses to intravenous injections of 2-(2-aminoethyl)pyridine, dimaprit and impromidine [22].
• Responses to gastrin were almost completely inhibited by ranitidine (10 microM) at a concentration which abolished the secretory response to dimaprit [23].
• Incubating HL-60 cells in the presence of the specific H2 agonist dimaprit resulted in 30-fold increases in cAMP levels (EC50 = 5.7 X 10(-6) M) and morphological changes suggestive of cell maturation along the granulocyte pathway [24].
• 1 The cardiovascular responses to dimaprit (S-(3-dimethylaminopropyl) isothiourea) a selective histamine H2-receptor agonist have been studied in anaesthetized cats, dogs, rats and rabbits [25].

Gene context of Dimaprit

• Furthermore, since dimaprit and IBMX stimulate gastric acid secretion independently of histamine release, sst2 receptor-mediated inhibition must occur at the level of the parietal cell itself [23].
• 2. Gastrin (1 nM-1 microM), dimaprit (10 microM-300 microM) and isobutyl methylxanthine (IBMX, 1 microM-100 microM) all caused concentration-dependent increases in acid output [23].
• 4. The inhibitory effect of a range of SRIF analogues on gastrin-, dimaprit- and IBMX-induced acid secretion was also studied [23].
• The histamine H2 receptor agonist, dimaprit (10 mg kg(-1), i.v.), was also without effect on the evoked mydriasis [26].
• The H2 receptor agonist dimaprit produced a marked relaxation [27].

Analytical, diagnostic and therapeutic context of Dimaprit

• 3 In the cat, continuous intravenous infusions of dimaprit lowered blood pressure without any significant change in heart rate or cardiac output [25].
• 2 Dimaprit lowered systemic arterial blood pressure in all species whether given by intravenous injection or by continous infusion [25].
• No other responses to histamine, SKF 71481-A2 or dimaprit were affected by vagotomy [28].
• 4 In about 50% of the vessels, a decrease in constriction frequency, STD activity and a smooth muscle hyperpolarization were observed in response to dimaprit (10 micro M), suggesting the presence of H(2) receptors [29].
• Intravenous infusion of dimaprit in the intact guinea pig resulted in reversal of bronchoconstriction induced by subcutaneous injection of 2-PEA [30].

References