Lithium levels in monkey and human brain after chronic, therapeutic, oral dosage.

Lithium levels in 32 different brain areas of 5 macacus rhesus receiving 13 mg/kg daily orally of lithium carbonate for 3-6 weeks are reported. These vary from 0.36 +/- 0.

Effects of L-prolyl-L-leucyl-glycine amide (MIF-I) on dopaminergic neurons.

In an attempt to determine the mechanism of action of L-proly-L-leucyl-glycine amide (MIF-I) in the treatment of Parkinson's disease, various parameters of dopaminergic neuronal function were studied in rats. It was found that the active uptake of 3H-dopamine (3H-DA) by synaptosome-rich homogenates of the striatum of rats treated with MIF-I (1 mg/kg IP X 3, 24 hr intervals) was unaltered 1 hr after final treatment with MIF-I. Also, neither tyrosine hydroxylase nor dopa decarboxylase activity was altered in the striatum and substantia nigra of rats treated with MIF-I (20 mg/kg IP X 3, 24 hr intervals).

Possible association of increased rat behavioral effects and increased striatal dopamine and norepinephrine levels during the DOPA-potentiation test.

Previous reports have indicated that alpha-MSH release inhibiting hormone (MIF-1) increased the behavior occurring as a result of the dihydroxyphenylalanine (DOPA) potentiation test [3,7]. This study was undertaken to see whether dopamine (DA) or norepinephrine (NE) levels likewise increased in the test animals. The DOPA potentiation test was performed as follows: 2-4 hr before behavior measurement, 40 mg/kg of the monoamine oxidase inhibitor pargyline HCl was given orally.

Investigations on alpha-MSH and MIF-1 effects on cyclic AMP levels in rat brain.

It has been suggested that the peptides alpha-metanocyte stimulating hormone (alpha-MSH) and MSH-release inhibitory factor (MIF-1) may alter adenosine-3', 5'-cyclic monophosphate (cAMP) metabolism [13,26]. Normal and hypophysectomized (hypoxed) rats were administered saline (controls IP daily X 3), alpha-MSH (80 mug/kg IP daily X 3) or MIF-1 (1 or 10 mg/kg IP daily X 3) and sacrificed 30 min after the third injection in a focused microwave oven (1.5 KW; 2-3 sec).

Alpha-MSH and MIF-I effects on catecholamine levels and synthesis in various rat brain areas.

Attempts were made to find a biochemical correlate with previously observed behavioral alterations after administration of alpha-melanocyte-stimulating hormone (MSH) and MSH release-inhibiting factor (MIF-I). Brains of intact and hypophysectomized (hypox) rats were analyzed for endogenous catecholamine levels and the disappearance rate of endogenous norepinephrine (NE) after treatment with the tyrosine hydroxylase inhibitor alpha-methyl-para-tyrosine (AMPT). The studies undertaken show the following: (1) After the injection of MSH (100 mug/kg IP daily x 3) and AMPT, samples in different groups of intact and hypox rats were taken at 0, 1, 2, 4 and 6 hrs in 7 different brain areas.

Alpha-MSH and MIF-2 effects on serotonin levels and accumulation in various rat brain areas.

Levels as well as accumulation of serotonin (5-HT) were measured in various brain regions of the rat after administration of alpha-melanocyte-stimulating hormone (MSH) and Pro-Leu-Gly-NH2 (MIF-I). The method used in determining the serotonin measured both 5-OH-tryptamine (5-HT) and 5-methoxytryptamine (5-MT). No statistically significant changes in levels or accumulation of serotonin after pargyline injection were found when unoperated control rats were treated with either MSH or MIF-I.