MIF-1 fails to modify agonist-induced oral activity in neonatal 6-OHDA-treated rats.
L-Prolyl-L-leucyl-glycinamide (MIF-1) is known to attenuate apomorphine-induced stereotypes in adult rats that are lesioned as neonates with 6-hydroxydopamine (6-OHDA). To test whether MIF-1 would affect dopamine (DA) agonist-induced and serotonin (5-HT) agonist-induced oral activity, both intact and neonatal 6-OHDA-treated rats were studied. Rats at 3 days from birth were injected with desipramine (20 mg/kg, IP), 1 h before 6-OHDA HBr (100 micrograms, salt form, in each lateral ventricle) or its vehicle, saline-ascorbic acid (0.1%). At approximately 6 months rats were treated with MIF-1 (0.1, 1.0, or 10.0 mg/kg, IP), 10 min before SKF 38393 HCl (1.0 mg/kg, IP) or m-chlorophenylpiperazine 2HCl (m-CPP 2HCl; 0.5 mg/kg, IP), DA D1 and 5-HT1C,2 receptor agonists, respectively. Although both agonists increased oral activity in control and neonatal 6-OHDA-treated rats, MIF-1 did not modify the response. In rats that received either of the three doses of MIF-1 for 21 consecutive days, there was still no observed effect of MIF-1 on the oral response of control and 6-OHDA-lesioned rats to SKF 38393 and m-CPP. These findings indicate that MIF-1 does not modify the oral activity response of supersensitized D1 and 5-HT1C receptors in adult rats that are lesioned neonatally with 6-OHDA.
Gong
L
L
Department of Pharmacology, Quillen College of Medicine, East Tennessee State University, Johnson City 37614.
Kostrzewa
R M
RM
Kalbfleisch
J H
JH
D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D000831:Animals, Newborn; D015259:Dopamine Agents / Q000494:pharmacology*; D004347:Drug Interactions; D009075:MSH Release-Inhibiting Hormone / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009055:Mouth; D016627:Oxidopamine / Q000494:pharmacology*; D010879:Piperazines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*; D013239:Stereotyped Behavior / Q000187:drug effects*
D015259:Dopamine Agents; D010879:Piperazines; D017366:Serotonin Receptor Agonists; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D016627:Oxidopamine; D009075:MSH Release-Inhibiting Hormone; C015068:1-(3-chlorophenyl)piperazine