MIF-1: effects on norepinephrine, dopamine and serotonin metabolism in certain discrete brain regions.
A single injection of melanocyte-stimulating hormone inhibitory factor (MIF-1) in a dose of 3 mg/kg IP produced no significant effect on dopamine turnover. However, a dose of 5 mg/kg increased striatal tyrosine hydroxylase activity by 25% and homovanillic acid level by 27% when compared to control values. No change in either parameter was detected in olfactory tubercles. Dopamine levels also were elevated in striatum, pons-medulla and cerebral cortex in rats receiving 5 mg/kg dose of MIF-1. In olfactory tubercles, dopamine levels were however, reduced to 71% of control values taken as 100%. The concentration of norepinephrine tended to increase in several brain areas examined but, the change was statistically significant only in olfactory tubercles and cerebral cortex. The level of norepinephrine metabolite, 3-methoxy-4-hydroxyphenylethylene glycol, was lowered to 63% in whole brain of animals given MIF-1 at the dose of 5 mg/kg. These data suggest that MIF-1 enhances the turnover of dopamine and norepinephrine in the brain. However, MIF-1 treatment seemed to produce no consistent change in brain serotonin turnover. In striatum and cortex, this neuropeptide increased serotonin but elevated the level of its metabolite, 5-hydroxyindoleacetic acid indicating that the release of this brain amine was decreased in these two brain regions. The levels of 5-hydroxyindoleacetic acid were enhanced in hypothalamus and pons-medulla regardless of the dose of MIF-1 administered.
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002395:Catecholamines / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism; D009075:MSH Release-Inhibiting Hormone / Q000494:pharmacology*; D008297:Male; D009638:Norepinephrine / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism; D014365:Tryptophan Hydroxylase / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
D002395:Catecholamines; D012701:Serotonin; D009075:MSH Release-Inhibiting Hormone; D014446:Tyrosine 3-Monooxygenase; D014365:Tryptophan Hydroxylase; D004298:Dopamine; D009638:Norepinephrine