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At least 19 recordsLinked to original sources
PubMed1975

Selective impairment of atrioventricular conduction by 2-(2-pyridyl)-ethylamine and 2-(2-thiazolyl)-ethylamine, two histamine H1-receptor agonists.

To further characterize the receptor mediating histamine-induced impairment of atrioventricular conduction, the effects of two selective histamine H1-receptor agonists, 2-(2-pyridyl)-ethylamine (PEA) and 2-(2-thiazolyl)-ethylamine (ThEA), were investigated using the isolated guinea pig heart. These effects were compared with those of histamine and other selective agonists. PEA and ThEA produced a weak stimulation of cardiac rate and contractility; however, they produced a marked prolongation of atrioventricular conduction. The orders of relative potencies observed substantiate the hypothesis that H2-receptors mediate the positive inotropic and chronotropic effects and H1-receptors mediate the negative dromotropic effect of histamine.

Animals↗
PubMed1992

Synthesis and pharmacological characterization of 2-(4-chloro-3-hydroxyphenyl)ethylamine and N,N-dialkyl derivatives as dopamine receptor ligands.

2-(4-Chloro-3-hydroxyphenyl)ethylamine (4) and some derivatives were synthesized as dopamine (DA) receptor ligands. Amine 4 retains the dopaminergic pharmacophore 2-(3-hydroxyphenyl)-ethylamine, and the chlorine atom replaces the "para" hydroxyl group of DA. The derivatives 18a-e were obtained by introducing on the nitrogen of amine 4 the n-propyl and 2-phenylethyl or 3-phenylpropyl groups which can be accommodated by the D-2 receptor lipophilic sites 3C and pi 3, respectively. The affinity and selectivity of these compounds for D-1 and D-2 subtypes was determined in radioligand competition assays for the DA receptors of rat striatum membranes using [3H]SCH 23390 (D-1 selective) and [3H]spiperone (D-2 selective) as radioligands. The amine 4 shows about 7-fold lower affinity than DA for both sites and is not able to discriminate between the two subtypes of DA receptors. The introduction of two n-propyl groups (18a) on the nitrogen atom reduces by one-half and doubles the affinity for D-1 and D-2 binding sites, respectively. The substitution of an n-propyl group with different alkylphenyl groups, to give compounds 18b-e, increases the affinity for the D-2 subtype from 19-fold to 36-fold. These compounds have the same affinity at the D-2 site as the DA agonist N-n-propyl-N-(2-phenylethyl)-2-(3-hydroxyphenyl)-ethylamine (2a) and are about 20 times more selective than DA for this binding site. In the assay for D-2 receptor mediated inhibition of adenylate cyclase activity, all the tested compounds behaved as D-2 agonists; N-n-propyl-N-[2(4-hydroxyphenyl)ethyl]- (18d) and N-n-propyl-N-(2-phenyl-ethyl)-2-(4-chloro-3-hydroxyphenyl)ethylamine (18b) were more effective than DA or 2a. On the other hand, all compounds were less effective than DA in stimulation of adenylate cyclase activity in rat striatal homogenates, a kind of effect which is mediated by the D-1 subtype of DA receptors. These results suggest that the nitrogen substitution enhances the affinity and selectivity for the D-2 receptor. In the adenylate cyclase assay, the compounds behave as potent D-2 agonists.

Adenylyl Cyclases↗
PubMed1991

Behavioural evidence for central D-2 dopamine receptor agonistic effect by some 2-(fluorohydroxyphenyl)ethylamines.

The IP injection of 2-(4-fluoro-3-hydroxyphenyl)ethylamines. (FDA 24), N-n-propyl-N-(2-phenylethyl)-2-(3-fluoro-4-hydroxyphenyl)ethylamine (FDA 27F) and N-n-propyl-N-(2-phenylethyl)-2-(4-fluoro-3-hydroxyphenyl) ethylamine (FDA 40) into adult male rats induced the stretching and yawning (SY) syndrome, FDA 24 being the least active. Moreover, FDA 27F and FDA 40 potentiated penile erection (PE) with respect to controls. For both signs (PE and SY), FDA 40 was the most potent of the three compounds. These effects, which are considered typical signs of central D-2-dopamine (DA) receptor stimulation, were dose-related and significantly inhibited by pretreatment with the selective D-2 DA antagonist, sulpiride, but not by domperidone, which does not cross the hematoencephalic barrier. In previous binding studies, FDA 27F and FDA 40 showed high affinity and selectivity for D-2 DA receptors, while FDA 24 had a low affinity for both D-1 and D-2 DA receptors. The present data show that FDA 27F and FDA 40 cross the blood-brain barrier and exert an agonistic effect on the central D-2 DA receptors. These results also provide evidence of the value of PE and SY tests as sensitive tools for the study of DA-neurochemical mechanisms.

Animals↗
PubMed1990

Synthesis and dopamine receptor affinities of 2-(4-fluoro-3- hydroxyphenyl)ethylamine and N-substituted derivatives.

The synthesis of 2-(4-fluoro-3-hydroxyphenyl)ethylamine (26) and of some N,N-dialkyl derivatives (27-30) starting from 4-fluoro-3-hydroxytoluene and their in vitro binding affinities for dopamine (DA) receptor are reported. The amine 26 can be regarded as a molecular modification of DA in which the para hydroxyl group is replaced by fluorine. The new compounds 26-30 were evaluated for their affinity at D-1 and D-2 DA receptor subtypes by displacement of [3H]SCH 23390 (D-1 selective) and [3H]spiperone (D-2 selective). The amine 26 had about 2-fold less affinity for D-1 and D-2 binding sites than DA. The substitution of the amino group with ethyl, n-propyl, and 2-phenylethyl groups decreased the affinity for D-1 binding sites but greatly enhanced the effectiveness on D-2 binding sites. The N-ethyl- (28) and N-n-propyl-N-(2-phenylethyl)-2-(4-fluoro-3- hydroxyphenyl)ethylamine (30) were the most potent members of the series with high selectivity for D-2 binding sites. A similar effect was observed with isomeric N-n-propyl-N-(2-phenylethyl)-2-(3-fluoro-4-hydroxyphenyl)ethylamine (31) which was approximately 65 times more selective for D-2 sites vs D-1 sites. The introduction of a 2-phenylethyl group on the nitrogen atom induce the highest effect, perhaps as a consequence of an increased liposolubility or of binding to a complementary lipophilic site on the receptor.

Animals↗
PubMed1992

Structure-activity relationships of N-n-propyl-2-(4-fluoro-3-hydroxyphenyl)ethylamine derivatives as dopamine receptor ligands.

A series of N-n-propyl-2-(4-fluoro-3-hydroxyphenyl)ethylamine derivatives obtained by introducing on nitrogen atom a 2-phenylethyl moiety (with aromatic nucleus substituted at 3 or 4 position with fluorine, chlorine or hydroxy and methyl groups), as well as a 2-cyclohexylethyl or 3-phenylpropyl groups were synthesized. These substituents can interact with the D2 accessory binding site pi 3. The affinities of new compounds for D1 and D2 subtypes of dopamine (DA) receptor were measured in a test involving displacement of [3H]SCH 23390 and [3H]spiperone, respectively, from homogenates of rat striatum. The new derivatives are selective for D2 sites, and are more potent than the parent compound N-n-propyl-N-(2-phenylethyl)-2-(4-fluoro-3-hydroxyphenyl)ethylamine 2a. The N-n-propyl-N-[2-(4-hydroxyphenyl)ethyl]-2-(4-fluoro-3-hydroxyphenyl) ethylamine (11f) is the most potent and selective member in the series. Other derivatives are less effective but are as potent as the D2 agonist RU 24213. The results indicate that the pi 3 site is a rather large lipophilic pocket which can accommodate not only aromatic nuclei, but also the cyclohexyl group.

Animals↗
PubMed1986

Trace amines (ethylamine, octopamine, and tryptamine) stimulate inositol phospholipid hydrolysis in rat cerebral cortex slices.

Ethylamine, octopamine, tryptamine, and carbachol stimulate inositol phosphate accumulation in a dose-dependent way in rat cortical slices. Tyramine at 100 microM has no effect. The major inositol phosphate that is accumulated following stimulation is the monophosphate. The effect of carbachol is blocked by atropine but not by cyproheptadine, phenoxybenzamine, haloperidol or propranolol. None of the antagonists tried, including atropine, had an effect on the stimulation caused by ethylamine, octopamine or tryptamine.

Animals↗
PubMed1992

Synthesis, characterization, and biological evaluation of a novel class of N-(arylethyl)-N-alkyl-2-(1-pyrrolidinyl)ethylamines: structural requirements and binding affinity at the sigma receptor.

By synthesizing and testing a part-structure, N-[2-(3,4-dichlorophenyl)ethyl]-N-methyl-2-(1-pyrrolidinyl)ethylamine (3), derived from our previously reported high affinity sigma receptor ligands (1S,2R)-(-)-N-[2-(3,4-dichlorophenyl)-ethyl]-N-methyl-2-(1- pyrrolidinyl)cyclohexylamine [(-)-2] and (+)-2, we have identified a novel class of superpotent (subnanomolar affinity) sigma ligands specific for the sigma receptor labeled by [3H]-(+)-3-PPP. When 3 was tested for its capacity to displace [3H]-(+)-3-PPP from guinea pig brain membranes, it exhibited a Ki of 0.34 nM, which is better than either of its parent compounds (-)-2 (Ki = 1.3 nM) and (+)-2 (Ki = 6.0 nM). Other compounds related to 3 such as N-[2-(3,4-dichlorophenyl)ethyl]-N-methyl-2-(1-homopiperidinyl)ethy lamine (19) exhibited Ki = 0.17 nM [( 3H]-(+)-3-PPP). The determinants for high sigma receptor affinity of 3 were examined by manipulation of this structure in a number of different ways. The high efficacy of these compounds for the sigma receptor, their relative chemical simplicity and ease of synthesis, and their high degree of selective identifies N-[2-(3,4-dichlorophenyl)ethyl]-N-methyl-2-(1-pyrrolidinyl)ethylamine (3) and related compounds as a highly promising base for determination of the functional role of sigma receptors as well as the development of novel therapeutic agents.

Animals↗
PubMed1985

[The preparation and histaminergic properties of 2-(2-oxo-4-imidazolin-4-yl)ethylamine].

Carrying on the study of the effects induced by substitution at position 2- of histamine imidazole ring, this article briefly reports the synthesis of 2-(2-oxo-4-imidazolin-4-yl)ethylamine. The pharmacological properties of this compound and its sulphurated analogue 2-(2-thiono-4-imidazolin-4-yl)ethylamine, showed that the marked structural modification of the critical moieties involved in the binding at the H1- and H2-receptors resulted in a loss of histamine-like activity.

Animals↗
PubMed1987

Characterization of the amine oxidase involved in the growth of Trichosporon cutaneum X4 on ethylamine as source of carbon, nitrogen and energy.

The amine oxidase from Trichosporon cutaneum X4 grown on ethylamine as carbon, nitrogen and energy source was purified to near homogeneity. The purified enzyme showed the highest resistance to heat of any amine oxidase hitherto characterized from a yeast (half-life at 62 degrees C, 14 min). Measurement of kinetic parameters as a function of carbon chain length showed results typical of a benzylamine oxidase. Both non-denaturing- and sodium dodecyl sulphate-polyacrylamide gel electrophoresis showed multiple bands, and dimethyl suberimidate cross-linking studies revealed that the enzyme consisted of multimers of two polypeptide chains of Mr respectively 19,000 and 26,000. The smallest structure to show activity probably contained two of each kind of subunit.

Amine Oxidase (Copper-Containing)↗
PubMed1992

Syntheses of 2-(3,4-dimethoxyphenyl)ethylamine derivatives and their antiulcer activities.

A series of acyl derivatives of 2-(3,4-dimethoxyphenyl)ethylamine (4) were synthesized and evaluated for their effectiveness to prevent water-immersion stress-induced gastric ulceration when given intraperitoneally to rats. Among them N-[2-(3,4-dimethoxyphenyl)ethyl]-2-phenylaminoacetamide hydrochloride (15) had significant antiulcer activity. Further modification of the four parts of 15 revealed that only the introduction of a carbamoyl group into 2- or 3-position of the phenylamino part gave compounds (49-51, 54 and 55) which retained antiulcer activity comparable to the lead compound. However, the compounds (49-51 and 54) did not exert a prophylactic effect when administered orally except for the 3-substituted bezamide derivative 55. Alkyl substitution on the nitrogen of benzamide gave 3-[[[2-(3,4-dimethoxyphenyl)ethyl]carbamoyl]methyl] amino-N-methylbenzamide (66, DQ-2511) and the related compounds (67, 70, 74 and 77) which all had potent antiulcer activities at oral doses of 50-400 mg/kg.

Animals↗
PubMed1990

HPLC resolution of diacylglycerol moieties of natural triacylglycerols on a chiral phase consisting of bonded (R)-(+)-1-(1-naphthyl)ethylamine.

Chiral phase high performance liquid chromatographic resolution of sn-1,2(2,3)- and X-1,3-diacylglycerols generated by partial Grignard degradation from natural triacylglycerols was carried out using a chiral column (25 cm x 4.6 mm i.d.) containing (R)-(+)-1-(1-napthyl)ethylamine polymer chemically bonded to 300A wide pore spherical silica (5 microns particles). The diacylglycerols were chromatographed as 3,5-dinitrophenyl-urethanes and detected at 226 or 254 nm UV. By an isocratic elution with n-hexane- 1,2-dichloroethane-ethanol 40:10:1 (v/v/v) as the mobile phase, the sn-1,2(2,3)-diacylglycerols from corn, linseed, and menhaden oils were resolved into two clearly distinguishable enantiomer groups, although some peak overlappings between the enantiomers were observed in the linseed and menhaden oil diacylglycerols. In addition to the excellent enantiomer resolution, each enantiomer and the X-1,3-isomers were partially resolved into several peaks, which could be tentatively identified on the basis of equivalent carbon number. It is concluded that chiral phase high performance liquid chromatography can be utilized for effective resolution, identification, and quantitation of enantiomeric diacylglycerols from complex natural mixtures.

Chromatography, High Pressure Liquid↗
PubMed1987

[Trans-1-(4-phenylcyclohexyl)ethylamine derivatives with antidepressant activity. II].

Some derivatives of trans-1-(4-phenylcyclohexyl)ethylamine (A) with a substituent at position 4 of the phenyl group were prepared and tested for antireserpine activity on the CNS. All compounds showed reduced activity compared with that of (A) except the amino derivative (II) which proved more active but at the same time showed increased toxicity and other adverse effects on the CNS.

5-Hydroxytryptophan↗
PubMed1990

2-Phenyl-2-(1-hydroxycycloalkyl)ethylamine derivatives: synthesis and antidepressant activity.

A series of 2-phenyl-2-(1-hydroxycycloalkyl)ethylamine derivatives was examined for the ability to inhibit both rat brain imipramine receptor binding and the synaptosomal uptake of norepinephrine (NE) and serotonin (5-HT). Neurotransmitter uptake inhibition was highest for a subset of 2-phenyl-2-(1-hydroxycyclohexyl)dimethylethylamines in which the aryl ring has a halogen or methoxy substituent at the 3- and/or 4-positions. Potential antidepressant activity in this subset was assayed in three rodent models--the antagonism of reserpine-induced hypothermia, the antagonism of histamine-induced ACTH release, and the ability to reduce noradrenergic responsiveness in the rat pineal gland. An acute effect seen in the rat pineal gland with several analogues, including 1-[1-(3,4-dichlorophenyl)-2-(dimethylamino)ethyl]cyclohexanol (23) and 1-[2-(dimethylamino)-1)-(4-methoxyphenyl)ethyl]cyclohexanol (4), was taken as a possible correlate of a rapid onset of antidepressant activity. Compound 4 (venlafaxine) is presently undergoing clinical evaluation.

Adrenocorticotropic Hormone↗
PubMed1977

Metabolic products of N-ethyl-beta-methoxy-beta-(3'-trifluoromethylphenyl)ethylamine (SKF 40652A).

The metabolsim of N-ethyl-beta-methoxy-beta-(3'-trifluoromethylphenyl)ethylamine (SKF 40652A, I) in vitro with 9000 g supernatants and washed microsomes of rabbit liver gave N-dealkylation, and N-oxidation of the parent secondary amine and the derived primary amine, anti and syn beta-methoxy-beta-(3'-trifluoromethylphenyl)acetaldoximes (V), and the beta-methoxy-beta-(3'-trifluoromethylphenyl(ethyl alcohol (VI). The identification and the physicochemical properties of these compounds are reported.

Animals↗
PubMed1988

Synthesis and dopamine receptors binding affinity of 2-(3-fluoro-4-hydroxyphenyl)ethylamine and its N-alkyl derivatives.

The 2-(3-fluoro-4-hydroxyphenyl)ethylamine and its N,N-dialkyl derivatives were synthesized. The affinity of new compounds for dopamine binding sites was measured in a test involving displacement of [3H]SCH 23390 (D-1 selective) and [3H]spiperone (D-2 selective) from homogenized rat striatal tissue. No compound proved effective in displacing [3H]SCH 23390. Two derivatives are selective displacers of [3H]spiperone.

Animals↗