EurekaMag.com logo
+ Site Statistics
References:
47,893,527
Abstracts:
28,296,643
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Evidence that 8 hydroxy 2 n dipropylaminotetralin 8 oh dpat is a selective alpha 2 adrenoceptor antagonist on guinea pig submucous neurons


, : Evidence that 8 hydroxy 2 n dipropylaminotetralin 8 oh dpat is a selective alpha 2 adrenoceptor antagonist on guinea pig submucous neurons. British Journal of Pharmacology 92(2): 341-348

Intracellular recordings were made from neurones of the submucous plexus and from submucosal arteriolar smooth muscle of the guinea-pig ileum for the purpose of examining the actions of 8-hydroxy-2-(n-dipropylamino)tetralin (8-OH-DPAT). 8-OH-DPAT (10 nM-20 .mu.M) had no direct presynaptic or postsynaptic actions on submucous plexus neurones. Membrane hyperpolarizations induced in neurones by noradrenaline or UK 14304 were competitively antagonized by 8-OH-DPAT. For dose-ratios up to 40, Schild plots were linear with slopes not significantly different from unity; pA2, values for the 8-OH-DPAT antagonism of postsynaptic .alpha.2-adrenceptors were 6.9-7.2. The inhibitory synaptic potential, which is due to activation of .alpha.2-adrenoceptors located on submucous plexus neurones, was selectively inhibited by 8-OH-DPAT; the IC50 value for inhibition of the inhibitory synaptic potential was 250 nM. Neuronal hyperpolarizations mediated through activation of .delta.-opioid receptors or somatostatin receptors were unaffected by 8-OH-DPAT (0.1-1 .mu.M). The ability of noradrenaline and UK 14304 to inhibit the release of acetylcholine at synapses in the submucous plexus, and to inhibit the release of the transmitter which mediates the excitatory junction potential in the submucosal arteriolar smooth muscle, was also blocked by 8-OH-DPAT. These results suggests that some of the actions of 8-OH-DPAT previously ascribed to agonism at 5-hydroxytryptamine (5-HT)1 receptors may actually result from blockade of the actions of endogenously released noradrenaline acting on .alpha.2-adrenoceptors.


Accession: 005411967

PMID: 2890393

Submit PDF Full Text: Here


Submit PDF Full Text

No spam - Every submission is manually reviewed

Due to poor quality, we do not accept files from Researchgate

Submitted PDF Full Texts will always be free for everyone
(We only charge for PDFs that we need to acquire)

Select a PDF file:
Close
Close

Related references

Crist, J.; Surprenant, A., 1987: Evidence that 8-hydroxy-2-(n-dipropylamino)tetralin (8-OH-DPAT) is a selective alpha 2-adrenoceptor antagonist on guinea-pig submucous neurones. 1 Intracellular recordings were made from neurones of the submucous plexus and from submucosal arteriolar smooth muscle of guinea-pig ileum for the purpose of examining the the actions of 8-hydroxy-2-(n-dipropylamino)tetralin (8-OH-DPAT). 2 8-OH-D...

Karlsson A.; Bjork L.; Pettersson C.; Anden N E.; Hacksell U., 1990: R 5 hydroxy 2 dipropylaminotetralin and s 5 hydroxy 2 dipropylaminotetralin 5 oh dpat assessment of optical purities and dopaminergic activities. Racemic 5-hydroxy-2-(dipropylamino)tetralin (5-OH DPAT), a potent and selective dopamine (DA) D2-receptor agonist, was resolved into the enantiomers by the new method. The enantiomers of 5-OH DPAT were determined by chiral ion-pair chromatography...

Trezise D.; Stubbs C.M.; Connor H.E.; Feniuk W., 1990: Alpha 1 adrenoceptor antagonist effects of the 5 ht 1a agonist 8 hydroxy dpat. British Journal of Pharmacology 100(PROC SUPPL JUNE): 464P

North R.A.; Surprenant A., 1985: Inhibitory synaptic potentials resulting from alpha 2 adrenoceptor activation in guinea pig submucous plexus neurons. Intracellular recordings were obtained from neurons of the guinea-pig submucous plexus. Inhibitory synaptic potentials (i.p.s.p.) were compared with hyperpolarizations evoked by brief, local applications of noradrenaline [norepinephrine, NE] and b...

Surprenant A., 1987: On the ionic mechanisms of alpha 2 adrenoceptor mediated presynaptic inhibition in guinea pig submucous plexus neurons. Society for Neuroscience Abstracts 13(2): 1441

Karlsson A.; Pettersson C.; Sundell S.; Arvidsson L E.; Hacksell U., 1988: Improved preparation chromatographic separation and x ray crystallographic determination of the absolute configuration of the enantiomers of 8 hydroxy 2 dipropylaminotetralin 8 hydroxy dpat. 2-Benzylamino-8-methoxytetralin (2), which serves as a synthetic intermediate for (+)- and (-)-8-hydroxy-2-(dipropylamino)tetralin (1), was resolved into the enantiomers by fractional crystallization of the di-p-toluoyltartrates. This procedure is...

Asano M.; Hashimoto H.; Nakashima M., 1983: Affinities for alpha adrenoceptor and beta adrenoceptor subtypes of ym 09538 5 1 hydroxy 2 2 o methoxyphenoxyethylaminoethyl 2 methyl benzenesulfonamide hydro chloride a new combined alpha adrenoceptor and beta adrenoceptor antagonist by radio ligand binding assay. The binding properties of YM-09538 and some known adrenoceptor agonists and antagonists to .alpha.- and .beta.-adrenoceptors were studied by radioligand binding assays using [3H]-prazosin, [3H]-clonidine and (-)-[3H]-dihydroalprenolol ([3H]-DHA)....

Tanaka T.; Stamm G.; Starke K., 1980: Evidence against agonist selective and antagonist selective alpha adrenoceptor subtypes. Naunyn-Schmiedeberg's Archives of Pharmacology 311(SUPPL): R59

Critchley M.A.E.; Njung'e K.; Handley S.L., 1988: Prevention of 8 hydroxy dpat anxiogenic effect by ipsapirone and by 5 ht 1 antagonist beta adrenoceptor antagonists. British Journal of Pharmacology 94(PROC SUPPL): 389P

Gmeiner, P.; Hummel, E.; Mierau, J., 1994: Novel HO-DPAT (Hydroxy-2-dipropylaminotetralin) isomers: Stereoselective synthesis and receptor binding studies. The synthesis of the novel HO-DPAT isomers 2 and 3 from the beta-amino acid 4 is reported. 2 showed strong and selective affinity to the dopamine autoreceptor, labelled with (3H)-pramipexole.