Biomaterial Database

24h withdrawal following repeated administration of caffeine attenuates brain serotonin but not tryptophan in rat brain: implications for caffeine-induced depression. 1995

D J Haleem, and A Yasmeen, and M A Haleem, and A Zafar

Department of Biochemistry, University of Karachi, Pakistan.

Caffeine injected at doses of 20, 40 and 80 mg/kg increased brain levels of tryptophan, 5-hydroxytryptamine (5-HT) and 5-hydroxyindole acetic acid (5-HIAA) in rat brain. In view of a possible role of 5-HT in caffeine-induced depression the effects of repeated administration of high doses of caffeine on brain 5-HT metabolism are investigated in rats. Caffeine was injected at doses of 80 mg/kg daily for five days. Control animals were injected with saline daily for five days. On the 6th day caffeine (80 mg/kg) injected to 5 day saline injected rats increased brain levels of tryptophan, 5-HT and 5-HIAA. Plasma total tryptophan levels were not affected and free tryptophan increased. Brain levels of 5-HT and 5-HIAA but not tryptophan decreased in 5 day caffeine injected rats injected with saline on the 6th day. Plasma total and free tryptophan were not altered in these rats. Caffeine-induced increases of brain tryptophan but not 5-HT and 5-HIAA were greater in 5 day caffeine than 5 day saline injected rats. The findings are discussed as repeated caffeine administration producing adaptive changes in the serotonergic neurons to decrease the conversion of tryptophan to 5-HT and this may precipitate depression particularly in conditions of caffeine withdrawal.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D002110	Caffeine	A methylxanthine naturally occurring in some beverages and also used as a pharmacological agent. Caffeine's most notable pharmacological effect is as a central nervous system stimulant, increasing alertness and producing agitation. It also relaxes SMOOTH MUSCLE, stimulates CARDIAC MUSCLE, stimulates DIURESIS, and appears to be useful in the treatment of some types of headache. Several cellular actions of caffeine have been observed, but it is not entirely clear how each contributes to its pharmacological profile. Among the most important are inhibition of cyclic nucleotide PHOSPHODIESTERASES, antagonism of ADENOSINE RECEPTORS, and modulation of intracellular calcium handling.	1,3,7-Trimethylxanthine,Caffedrine,Coffeinum N,Coffeinum Purrum,Dexitac,Durvitan,No Doz,Percoffedrinol N,Percutaféine,Quick-Pep,Vivarin,Quick Pep,QuickPep
D003863	Depression	Depressive states usually of moderate intensity in contrast with MAJOR DEPRESSIVE DISORDER present in neurotic and psychotic disorders.	Depressive Symptoms,Emotional Depression,Depression, Emotional,Depressive Symptom,Symptom, Depressive
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D004334	Drug Administration Schedule	Time schedule for administration of a drug in order to achieve optimum effectiveness and convenience.	Administration Schedule, Drug,Administration Schedules, Drug,Drug Administration Schedules,Schedule, Drug Administration,Schedules, Drug Administration
D006897	Hydroxyindoleacetic Acid		5-HIAA,5-Hydroxy-3-Indoleacetic Acid,5-Hydroxyindolamine Acetic Acid,5 Hydroxy 3 Indoleacetic Acid,5 Hydroxyindolamine Acetic Acid,Acetic Acid, 5-Hydroxyindolamine,Acid, 5-Hydroxy-3-Indoleacetic,Acid, 5-Hydroxyindolamine Acetic,Acid, Hydroxyindoleacetic
D000704	Analysis of Variance	A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.	ANOVA,Analysis, Variance,Variance Analysis,Analyses, Variance,Variance Analyses
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012701	Serotonin	A biochemical messenger and regulator, synthesized from the essential amino acid L-TRYPTOPHAN. In humans it is found primarily in the central nervous system, gastrointestinal tract, and blood platelets. Serotonin mediates several important physiological functions including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity. Multiple receptor families (RECEPTORS, SEROTONIN) explain the broad physiological actions and distribution of this biochemical mediator.	5-HT,5-Hydroxytryptamine,3-(2-Aminoethyl)-1H-indol-5-ol,Enteramine,Hippophaine,Hydroxytryptamine,5 Hydroxytryptamine