Biomaterial Database

Modulation of the discriminative stimulus properties of cocaine by 5-HT1B and 5-HT2C receptors. 1995

P M Callahan, and K A Cunningham

Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, USA.

The present study assessed compounds displaying affinity for 5-HT1A, 5-HT1B, 5-HT2A and 5-HT2C receptors for their ability to substitute for, enhance or antagonize the discriminative stimulus effects of cocaine (10 mg/kg) in rats. In substitution tests, the 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT; 0.2-1.6 mg/kg), the 5-HT1A/B receptor agonists RU 24969 (0.25-2 mg/kg) and CGS 12066B (2-16 mg/kg), the 5-HT1B/2C receptor agonists m-chlorophenylpiperazine (mCPP; 0.25-2 mg/kg) and m-trifluoromethylphenylpiperazine (TFMPP; 0.125-2 mg/kg), the 5-HT2A/2C receptor agonist 1-(4-bromo-2,5-dimethoxyphenyl)-2-aminopropane ([+/-]-DOB; 0.0625-0.5 mg/kg), the 5-HT2C receptor agonist MK 212 (0.25-1 mg/kg) and the nonselective 5-HT receptor agonist quipazine (1-8 mg/kg) engendered 30% to 70% cocaine-appropriate responding. The DA receptor antagonists SCH 23390 (0.025 or 0.05 mg/kg) and haloperidol (0.125 or 0.25 mg/kg) failed to block the partial substitution of RU 24969 (1 mg/kg) for cocaine. In combination tests, a fixed dose of either quipazine (4 mg/kg), RU 24969 (0.25, 0.5 or 1 mg/kg) or TFMPP (0.5 mg/kg) but not 8-OH-DPAT (0.4 mg/kg) or CGS 12066B (16 mg/kg) produced a leftward shift in the cocaine dose-response curve (0.625-5 mg/kg). In contrast, coadministration of either mCPP (0.25-2 mg/kg) or MK 212 (0.125-2 mg/kg) plus a dose of cocaine (5 mg/kg) that produced > 85% cocaine-appropriate responding when given alone partially antagonized cocaine; mCPP (1 mg/kg) also produced a rightward shift in the cocaine dose-response curve. Neither 8-OH-DPAT (0.2-1.6 mg/kg), (+/-)-DOB (0.125-0.5 mg/kg) nor quipazine (2-8 mg/kg) blocked the cocaine stimulus. The 5-HT1A receptor antagonist NAN 190 (0.2-0.8 mg/kg), the 5-HT2A/2C receptor antagonist LY 53857 (0.5-4 mg/kg) and the 5-HT/DA receptor antagonist pirenperone (0.5-4 mg/kg) neither substituted for nor enhanced cocaine; however, pirenperone but not NAN 190 or LY 53857 partially blocked the cocaine (10 mg/kg) response. Although 5-HT receptor compounds do not substitute for cocaine, several 5-HT receptor agonists (i.e., the indole derivative RU 24969 and the arylpiperazines mCPP, MK 212, TFMPP and quipazine), but not antagonists, differentially modulate the stimulus effects of cocaine.(ABSTRACT TRUNCATED AT 400 WORDS)

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009294	Narcotics	Agents that induce NARCOSIS. Narcotics include agents that cause somnolence or induced sleep (STUPOR); natural or synthetic derivatives of OPIUM or MORPHINE or any substance that has such effects. They are potent inducers of ANALGESIA and OPIOID-RELATED DISORDERS.	Analgesics, Narcotic,Narcotic Analgesics,Narcotic,Narcotic Effect,Narcotic Effects,Effect, Narcotic,Effects, Narcotic
D011985	Receptors, Serotonin	Cell-surface proteins that bind SEROTONIN and trigger intracellular changes which influence the behavior of cells. Several types of serotonin receptors have been recognized which differ in their pharmacology, molecular biology, and mode of action.	5-HT Receptor,5-HT Receptors,5-Hydroxytryptamine Receptor,5-Hydroxytryptamine Receptors,Receptors, Tryptamine,Serotonin Receptor,Serotonin Receptors,Tryptamine Receptor,Tryptamine Receptors,Receptors, 5-HT,Receptors, 5-Hydroxytryptamine,5 HT Receptor,5 HT Receptors,5 Hydroxytryptamine Receptor,5 Hydroxytryptamine Receptors,Receptor, 5-HT,Receptor, 5-Hydroxytryptamine,Receptor, Serotonin,Receptor, Tryptamine,Receptors, 5 HT,Receptors, 5 Hydroxytryptamine
D003042	Cocaine	An alkaloid ester extracted from the leaves of plants including coca. It is a local anesthetic and vasoconstrictor and is clinically used for that purpose, particularly in the eye, ear, nose, and throat. It also has powerful central nervous system effects similar to the amphetamines and is a drug of abuse. Cocaine, like amphetamines, acts by multiple mechanisms on brain catecholaminergic neurons; the mechanism of its reinforcing effects is thought to involve inhibition of dopamine uptake.	Cocaine HCl,Cocaine Hydrochloride,HCl, Cocaine,Hydrochloride, Cocaine
D004193	Discrimination Learning	Learning that is manifested in the ability to respond differentially to various stimuli.	Discriminative Learning,Discrimination Learnings,Discriminative Learnings,Learning, Discrimination,Learning, Discriminative
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
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
D012702	Serotonin Antagonists	Drugs that bind to but do not activate serotonin receptors, thereby blocking the actions of serotonin or SEROTONIN RECEPTOR AGONISTS.	5-HT Antagonist,5-HT Antagonists,5-Hydroxytryptamine Antagonist,5-Hydroxytryptamine Antagonists,Antiserotonergic Agent,Antiserotonergic Agents,Serotonin Antagonist,Serotonin Blockader,Serotonin Blockaders,Serotonin Receptor Antagonist,Serotonin Receptor Blocker,Antagonists, 5-HT,Antagonists, 5-Hydroxytryptamine,Antagonists, Serotonin,Serotonin Receptor Antagonists,Serotonin Receptor Blockers,5 HT Antagonist,5 HT Antagonists,5 Hydroxytryptamine Antagonist,5 Hydroxytryptamine Antagonists,Agent, Antiserotonergic,Agents, Antiserotonergic,Antagonist, 5-HT,Antagonist, 5-Hydroxytryptamine,Antagonist, Serotonin,Antagonist, Serotonin Receptor,Antagonists, 5 HT,Antagonists, 5 Hydroxytryptamine,Antagonists, Serotonin Receptor,Blockader, Serotonin,Blockaders, Serotonin,Blocker, Serotonin Receptor,Blockers, Serotonin Receptor,Receptor Antagonist, Serotonin,Receptor Antagonists, Serotonin,Receptor Blocker, Serotonin,Receptor Blockers, Serotonin
D017207	Rats, Sprague-Dawley	A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.	Holtzman Rat,Rats, Holtzman,Sprague-Dawley Rat,Rats, Sprague Dawley,Holtzman Rats,Rat, Holtzman,Rat, Sprague-Dawley,Sprague Dawley Rat,Sprague Dawley Rats,Sprague-Dawley Rats
D017366	Serotonin Receptor Agonists	Endogenous compounds and drugs that bind to and activate SEROTONIN RECEPTORS. Many serotonin receptor agonists are used as ANTIDEPRESSANTS; ANXIOLYTICS; and in the treatment of MIGRAINE DISORDERS.	5-HT Agonists,5-Hydroxytryptamine Agonists,Serotonin Agonists,5-HT Agonist,5-Hydroxytrytamine Agonist,Receptor Agonists, Serotonin,Serotonergic Agonist,Serotonergic Agonists,Serotonin Agonist,Serotonin Receptor Agonist,5 HT Agonist,5 HT Agonists,5 Hydroxytryptamine Agonists,5 Hydroxytrytamine Agonist,Agonist, 5-HT,Agonist, 5-Hydroxytrytamine,Agonist, Serotonergic,Agonist, Serotonin,Agonist, Serotonin Receptor,Agonists, 5-HT,Agonists, 5-Hydroxytryptamine,Agonists, Serotonergic,Agonists, Serotonin,Agonists, Serotonin Receptor,Receptor Agonist, Serotonin