PMID- 1081901
OWN - NLM
STAT- MEDLINE
DCOM- 19760315
LR  - 20190613
IS  - 0006-8993 (Print)
IS  - 0006-8993 (Linking)
VI  - 101
IP  - 3
DP  - 1976 Jan 23
TI  - In vivo release of 5-HT in the lateral ventricle of the rat: effects of 
      5-hydroxytryptophan and tryptophan.
PG  - 533-48
AB  - The in vivo release of 5-HT was examined in the rat brain. For this purpose, the 
      left lateral ventricle was perfused at a constant rate with an artificial CSF for 
      several hours in animals anaesthetized with halothane. 5-HT was estimated in 
      serial 1-h collected fractions. The amine was first isolated by adsorption on a 
      Sephadex G-10 column and then assayed using the radioenzymatic method of Saavedra 
      et al.37, slightly modified to improve its sensitivity. The quantity of 5-HT 
      released spontaneously during the first hour fraction was 296 pg, it was lower 
      (99 pg/h) in the following fractions. 5-HT released into the CSF may in great 
      part originate from serotoninergic terminals localized in structures surrounding 
      the ventricle. This was suggested by experiments in which exogenous [3H]5-HT or 
      [3H]tryptophan were perfused through the lateral ventricle during a few hours. 
      [3H]5-HT taken up or synthetized was mainly localized in structures surrounding 
      the ventricular space. The acute injection of 5-hydroxytryptophan (100 mg/kg) 
      induced an immediate important and long lasting increase of 5-HT release. In 
      contrast the acute injection of tryptophan (100 mg/kg) led to a transient and 
      moderate elevation of 5-HT release which was only detected during the second hour 
      of perfusion. Curiously a similar pattern of transmitter release was observed 
      following the constant intravenous infusion of the amino acid (70 mg/kg/h) except 
      that the increase in 5-HT release was much more pronounced during the second hour 
      than after the acute injection. Parallel experiments were made to determine the 
      time course of the changes of free and total tryptophan levels in plasma and of 
      those of tryptophan, 5-HT, and 5-hydroxyindoleacetic-acid (5-HIAA) in brain 
      tissues, induced by the acute and long term administrations of tryptophan. 
      Moreover the rate of 5-HT synthesis was estimated using the monoamine oxidase 
      inhibition method 2 and 5 h after both tryptophan treatments in halothane 
      anaesthetized rats. 5-HT levels and the synthesis rate of the transmitter were 
      increased at 2 h (when both tryptophan treatments stimulated 5-HT release). 
      Despite the presence of high tryptophan levels in plasma and tissues and of high 
      5-HT and 5-HIAA levels in tissues, the synthesis rate of 5-HT (as the 5-HT 
      release) was similar to that of controls 5 h after the onset of tryptophan 
      infusion. These results suggest that some relationships occurred between the 
      changes in 5-HT SYNTHESIs and release after the first hour of perfusion. The 
      absence of effects of tryptophan treatments on 5-HT release during the first hour 
      of perfusion are also discussed.
FAU - Ternaux, J P
AU  - Ternaux JP
FAU - Boireau, A
AU  - Boireau A
FAU - Bourgoin, S
AU  - Bourgoin S
FAU - Hamon, M
AU  - Hamon M
FAU - Hery, F
AU  - Hery F
FAU - Glowinski, J
AU  - Glowinski J
LA  - eng
PT  - Journal Article
PL  - Netherlands
TA  - Brain Res
JT  - Brain research
JID - 0045503
RN  - 333DO1RDJY (Serotonin)
RN  - 8DUH1N11BX (Tryptophan)
RN  - C1LJO185Q9 (5-Hydroxytryptophan)
SB  - IM
MH  - 5-Hydroxytryptophan/*pharmacology
MH  - Animals
MH  - Cerebral Ventricles/*drug effects/metabolism
MH  - Infusions, Parenteral
MH  - Injections, Intraperitoneal
MH  - Male
MH  - Rats
MH  - Serotonin/*metabolism
MH  - Tryptophan/administration & dosage/*pharmacology
EDAT- 1976/01/23 00:00
MHDA- 1976/01/23 00:01
CRDT- 1976/01/23 00:00
PHST- 1976/01/23 00:00 [pubmed]
PHST- 1976/01/23 00:01 [medline]
PHST- 1976/01/23 00:00 [entrez]
AID - 0006-8993(76)90476-5 [pii]
AID - 10.1016/0006-8993(76)90476-5 [doi]
PST - ppublish
SO  - Brain Res. 1976 Jan 23;101(3):533-48. doi: 10.1016/0006-8993(76)90476-5.