title: Restricted access to standard or high fat chow alters sensitivity of rats to the 5-HT(2A/2C) receptor agonist 1-(2,5-dimethoxy-4-methylphenyl)-2-aminopropane.
abstract: Feeding conditions can impact sensitivity to drugs acting on dopamine receptors; less is known about the impact of feeding conditions on the effects of drugs acting on serotonin (5-HT) receptors. This study examined the effects of feeding conditions on sensitivity to the direct-acting 5-HT(2A/2C) receptor agonist 1-(2,5-dimethoxy-4-methylphenyl)-2-aminopropane (DOM; 0.1-3.2 mg/kg) and the direct-acting dopamine D3/D2 receptor agonist quinpirole (0.0032-0.32 mg/kg). Male Sprague-Dawley rats had free access (11 weeks), followed by restricted access (6 weeks), to high fat (34.3%, n=8) or standard (5.7% fat; n=7) chow. Rats eating high fat chow became insulin resistant and gained more weight than rats eating standard chow. Free access to high fat chow did not alter sensitivity to DOM-induced head twitch but increased sensitivity to quinpirole-induced yawning. Restricting access to high fat or standard chow shifted the DOM-induced head twitch dose-response curve to the right and shifted the quinpirole-induced yawning dose-response curve downward in both groups of rats. Some drugs of abuse and many therapeutic drugs act on 5-HT and dopamine systems; these results show that feeding conditions impact sensitivity to drugs acting on these systems, thereby possibly affecting vulnerability to abuse, as well as the therapeutic effectiveness of drugs.
authors.affiliation: Departments of aPharmacology bPsychiatry, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA.
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Serafine
authors.forename: Charles P
authors.initials: CP
authors.lastname: France
mesh_terms: D004290:DOM 2,5-Dimethoxy-4-Methylamphetamine / Q000494:pharmacology*; D000818:Animals; D001786:Blood Glucose / Q000187:drug effects; D001831:Body Temperature / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D059305:Diet, High-Fat; D018491:Dopamine Agonists / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005247:Feeding Behavior / Q000187:drug effects*; D019416:Head Movements / Q000187:drug effects; D007328:Insulin / Q000494:pharmacology; D007333:Insulin Resistance / Q000502:physiology; D008297:Male; D019257:Quinpirole / Q000494:pharmacology; D051381:Rats; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*; D013997:Time Factors; D015000:Yawning / Q000187:drug effects
chemical_list: D001786:Blood Glucose; D018491:Dopamine Agonists; D007328:Insulin; D017366:Serotonin Receptor Agonists; D004290:DOM 2,5-Dimethoxy-4-Methylamphetamine; D019257:Quinpirole