Article date: February 1980
By: P. AHLUWALIA, R.L. SINGHAL in Volume 71, Issue 2, pages 601-607
The effects of low‐dose lithium administration (2 mEq/kg, daily) and its subsequent withdrawal have been examined with reference to changes in biogenic amine systems in several discrete regions of rat brain.
Increased levels of striatal tyrosine and midbrain tryptophan were found following lithium administration together with slight decreases in striatal tyrosine hydroxylase and midbrain tryptophan hydroxylase activities. Withdrawal resulted in a decrease in tyrosine content with increased tyrosine hydroxylase activity, whilst tryptophan levels and tryptophan hydroxylase activity were increased.
Lithium treatment and withdrawal resulted in altered levels of noradrenaline and dopamine, these changes being regionally variable. 3‐Methoxy‐4‐hydroxyphenylglycol content was depressed in both treated and withdrawal rats as were 3,4‐dihydroxyphenylacetic acid levels. Homovanillic acid decreased as a result of lithium treatment, but was greatly elevated in the withdrawal group.
5‐Hydroxytryptamine content decreased in some brain regions following lithium treatment with return towards control values in withdrawal rats. 5‐Hydroxyindoleacetic acid levels also displayed a regional variation as a result of lithium treatment and withdrawal.
The implications of these observations in elucidating the pharmacological effect of lithium treatment and its subsequent withdrawal are discussed.
The effects of low‐dose lithium administration (2 mEq/kg, daily) and its subsequent withdrawal have been examined with reference to changes in biogenic amine systems in several discrete regions of rat brain.
Increased levels of striatal tyrosine and midbrain tryptophan were found following lithium administration together with slight decreases in striatal tyrosine hydroxylase and midbrain tryptophan hydroxylase activities. Withdrawal resulted in a decrease in tyrosine content with increased tyrosine hydroxylase activity, whilst tryptophan levels and tryptophan hydroxylase activity were increased.
Lithium treatment and withdrawal resulted in altered levels of noradrenaline and dopamine, these changes being regionally variable. 3‐Methoxy‐4‐hydroxyphenylglycol content was depressed in both treated and withdrawal rats as were 3,4‐dihydroxyphenylacetic acid levels. Homovanillic acid decreased as a result of lithium treatment, but was greatly elevated in the withdrawal group.
5‐Hydroxytryptamine content decreased in some brain regions following lithium treatment with return towards control values in withdrawal rats. 5‐Hydroxyindoleacetic acid levels also displayed a regional variation as a result of lithium treatment and withdrawal.
The implications of these observations in elucidating the pharmacological effect of lithium treatment and its subsequent withdrawal are discussed.
DOI: 10.1111/j.1476-5381.1980.tb10979.x
View this article