In vivo Conversion of
            <sup>3</sup>
            H-L-Tryptophan into
            <sup>3</sup>
            H-Serotonin in Brain Areas of Adrenalectomized Rats

Azmitia, Efrain C.; Algeri, S.; Costa, E.

doi:10.1126/science.169.3941.201

Cited by 90 publications

(18 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This result is consistent with the decrease in 5-HT turnover reported in the rat hippocampus by some authors 1 or 2 h after ADX [4, 5], but not with the decrease in 5-HT synthesis described 1 or 2 weeks after ADX [3]or the lack of change in 5-HT and 5-HIAA levels 2–8 days after ADX [1]. Our results support the hypothesis of a tonic activation of 5-HT turnover by corticosterone through GR in the mouse hippocampus.…”

Section: Discussionsupporting

confidence: 81%

“…Decreases in 5-HT synthesis and turnover were reported in various brain areas of ADX rats [3, 4, 5, 29]. Therefore, we hypothesized that 5-HT metabolism would be affected in TG mice presenting alterations of the HPA axis functioning.…”

Section: Discussionmentioning

confidence: 99%

“…Data related to the influence of corticosteroids upon basal 5-HT metabolism or 5-HT 1A autoreceptors involved in the regulation of 5-HT metabolism in the brain stem are contradictory [2, 3, 30, 31, 32]. Moreover, since 5-HT turnover was found to be decreased in the pons medulla but not in the midbrain area including the rostral pons after short-term ADX [5], the absence of difference in basal 5-HT metabolism in the brain stem between control and TG mice might result from the fact that our dissection includes all raphe nuclei and the surrounding area so that a region-specific effect might have been blunted.…”

Section: Discussionmentioning

confidence: 99%

“…Although some authors reported no change in indices of the basal metabolism of serotonin (5-hydroxytryptamine, 5-HT) in the hippocampus, cortex or striatum after adrenalectomy (ADX) [1, 2], others, using different recovery periods after surgery, showed that removal of corticosterone reduces indices of basal 5-HT synthesis and turnover in the brain stem where the raphe nuclei which contain the serotoninergic cell bodies are located and also in the hippocampus and hypothalamus [3, 4, 5]. Moreover, many studies reported that basal circulating corticosterone levels exert inhibitory effects on mRNA expression and/or binding characteristics and functions of 5-HT 1A , 5-HT 1B and 5-HT 2C receptors, particularly in the hippocampus, and some of these effects could be the consequence of corticosterone-induced changes in 5-HT turnover [6, 7].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Regional Serotonin Metabolism under Basal and Restraint Stress Conditions in the Brain of Transgenic Mice with Impaired Glucocorticoid Receptor Function

et al. 1999

View full text Add to dashboard Cite

Transgenic (TG) mice deficient in glucocorticoid receptors (GR) were used in order to study the effects of a reduced GR function on adrenocorticotropin hormone and corticosterone plasma levels and on serotonin metabolism in different brain areas under basal resting conditions, after a 30-min restraint stress and 60 min after the end of the restraint stress. There was no difference in basal or stress-induced levels of either adrenocorticotropin hormone or corticosterone in control and TG mice, but the return of adrenocorticotropin hormone to basal values after the end of the stress was delayed in TG mice. Under basal conditions, the ratio 5-hydroxyindoleacetic acid/5-hydroxytryptamine was decreased only in the hippocampus of TG mice compared to controls. In the brain stem, the ratio 5-hydroxyindoleacetic acid/5-hydroxytryptamine increased compared to basal values after a 30-min restraint stress and values were still high 60 min after the end of the restraint stress in both control and TG mice. In the hippocampus, the ratio 5-hydroxyindoleacetic acid/5-hydroxytryptamine increased at the end of the stress and returned to basal levels 60 min later in control mice, whereas there was no change at the end of the stress but an increase 60 min later in TG mice. Finally there was no change in serotonin metabolism in the cortex, striatum or hypothalamus in either group or situation. Our results support the hypothesis of a tonic activation of serotonin turnover by corticosterone through GR in the mouse hippocampus. Moreover, stress-induced stimulation of serotonin metabolism in the brain stem and hippocampus appears to be delayed in TG mice compared to control mice. These results are particularly relevant for mood disorders such as depression where alterations of serotoninergic transmission might be secondary to an impairment of GR functions.

show abstract

Section: Discussionsupporting

confidence: 81%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Regional Serotonin Metabolism under Basal and Restraint Stress Conditions in the Brain of Transgenic Mice with Impaired Glucocorticoid Receptor Function

et al. 1999

View full text Add to dashboard Cite

show abstract

“…Kizer et al (19) found an increased tyrosine hydroxylase activity in rats treated with dexamethasone. There are also reports that tryptophan hydroxylase activity increases with corticosterone injection (20,21), while others were not able to confirm the data (22). In addition, an increased turnover of serotonin was demonstrated after corticosterone treatment (23)(24)(25).…”

Section: Resultsmentioning

confidence: 73%

Effect of neonatal hydrocortisone treatment on brain monoamines in developing rats.

Kurosawa¹,

Kageyama²,

JOHN³

et al. 1980

Jpn.J.Pharmacol

View full text Add to dashboard Cite

Abstract-In our previous study, neonatal treatment with hydrocortisone was shown to produce a marked retardation of pituitary-adrenocortical development in infant rats. The present investigation was an attempt to determine whether or not the retarded activity is caused by functional changes in brain monoamine systems. In rats treated with hydrocortisone (0.5 mg/rat, s.c.) on the 2nd day of life, the development of whole brain was suppressed significantly. However, norepinephrine, dopamine and serotonin contents in the brain were higher in these rats than in controls. These changes of mono amine contents were apparent in the hypothalamus, diencephalon and pons-medulla oblongata.Our data suggest that monoaminergic nervous systems are potentiated with hydrocortisone in these brain regions, although the results do not necessarily explain the retarded hypothalamo-pituitary function.Neonatal treatment of rats with several corticosteroids caused a marked atrophy of the adrenal gland and the thymus, these producing the wasting syndrome (1). In the treated animals, circadian rhythm of plasma corticosterone appeared at 4 weeks of age, but the plasma levels of corticosterone were significantly lower than those of controls until 6 weeks (2). Since the secretion of ACTH is likely to be affected by brain monoamines (3), the lowered plasma corticosterone levels in neonatally hydrocortisone-treated rats might be related to changes in monoamine contents in the brain. In this regard, Ulrich et al. (4) reported that both norepinephrine and serotonin in the medial hypothalamus were elevated, but dopamine levels did not increase in those rats at 30 days of age. However, these workers determined the content in the hypothalamus at one age only. More recently, Nyakas (5) found an increased norepinephrine content in the hindbrain of 4 month old rats given corticosterone on the 3rd to 5th postnatal days. The present study was undertaken to observe serial changes in monoamine contents from 1 to 7 weeks of age in the brain of rats given hydrocortisone neonatally. Our results are related to the ontogenic pattern of brain monoamines, as affected by hydrocortisone treatment. MATERIALS AND METHODSMale and female Wistar rats were housed at a constant temperature of 25±2'C under controlled lighting (fluorescent illumination from 07:00 to 19:00). Rat biscuits (Oriental Yeast Co.) and water were given ad lib.Newborn rats were given 0.5 mg hydrocortisone acetate (Merck) in 0.05 ml solvent s.c., on the 2nd day of life. The solvent consisted of 0.4 % polysorbate-80, 0.5 % carboxy methylcellulose and 0.5% benzylalcohol in 0.9% NaCI. Control rats were given the solvent only. About three-fourths of the litters were treated with hydrocortisone and the remaining served as controls. The rats were left with their mothers until weaning at 21 days of life.Almost 1,000 newborn rats were used, but more than 50 % of the infant rats given hydro cortisone died within 10 days.The animals were decapitated between 13:00 and 14:00 hr. The whole brain was quickly remov...

show abstract

Effect of 5-Hydroxytryptophan on Serum Cortisol Levels in Major Affective Disorders

Meltzer

Umberkoman-Wiita

Robertson

et al. 1984

Arch Gen Psychiatry

190

View full text Add to dashboard Cite

In vivo Conversion of ³ H-L-Tryptophan into ³ H-Serotonin in Brain Areas of Adrenalectomized Rats

Cited by 90 publications

References 10 publications

Regional Serotonin Metabolism under Basal and Restraint Stress Conditions in the Brain of Transgenic Mice with Impaired Glucocorticoid Receptor Function

Regional Serotonin Metabolism under Basal and Restraint Stress Conditions in the Brain of Transgenic Mice with Impaired Glucocorticoid Receptor Function

Effect of neonatal hydrocortisone treatment on brain monoamines in developing rats.

Effect of 5-Hydroxytryptophan on Serum Cortisol Levels in Major Affective Disorders

Contact Info

Product

Resources

About

In vivo Conversion of 3 H-L-Tryptophan into 3 H-Serotonin in Brain Areas of Adrenalectomized Rats

Cited by 90 publications

References 10 publications

Regional Serotonin Metabolism under Basal and Restraint Stress Conditions in the Brain of Transgenic Mice with Impaired Glucocorticoid Receptor Function

Regional Serotonin Metabolism under Basal and Restraint Stress Conditions in the Brain of Transgenic Mice with Impaired Glucocorticoid Receptor Function

Effect of neonatal hydrocortisone treatment on brain monoamines in developing rats.

Effect of 5-Hydroxytryptophan on Serum Cortisol Levels in Major Affective Disorders

Contact Info

Product

Resources

About

In vivo Conversion of ³ H-L-Tryptophan into ³ H-Serotonin in Brain Areas of Adrenalectomized Rats