EurekaMag.com logo
+ Site Statistics
References:
52,725,316
Abstracts:
28,411,598
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Differences in the kinetics of dopamine uptake in synaptosome preparations of the median eminence relative to other dopaminergically innervated brain regions


Neuroendocrinology 31(5): 316-320
Differences in the kinetics of dopamine uptake in synaptosome preparations of the median eminence relative to other dopaminergically innervated brain regions
A comparison of the kinetics of dopamine uptake was made in synaptosomal preparations of the [rat] median eminence, striatum and olfactory tubercle. Double reciprocal Lineweaver-Burk plots of the initial velocity vs. the concentration of dopamine yielded a single straight line in all 3 areas. The Km in the median eminence (1.8 .+-. 0.9 .times. 10-6 M) was significantly higher (P < 0.05) than in the striatum (4.2 .+-. 0.8 .times. 10-8 M) or olfactory tubercle (6.3 .+-. 1.9 .times. 10-8 M). Uptake in the median eninence appeared to be predominantly into dopaminergic terminals since preincubation with desipramine did not affect the Vmax of dopamine uptake. Observed uptake was predominantly due to transport across the neuronal membrane and not into storage granules, since reserpine only caused a small decrease in uptake. The low affinity of dopamine uptake in median eminence synaptosomes is consistent with the neurosecretory nature of these terminals; in the striatum and olfactory tubercle, high affinity reuptake is consistent with the role of dopamine as a neurotransmitter.


Accession: 005151353

PMID: 7442934



Related references

Differences in the kinetics of dopamine uptake in synaptosome preparations of the median eminence relative to other dopaminergically inervated brain regions. Neuroendocrinology 31(5): 316-320, 1980

Differences in the kinetics of dopamine uptake in synaptosomal preparations of the median eminence and neurointermediate lobe of the pituitary relative to the striatum and olfactory tubercle. Federation Proceedings 38(3 PART 1): 983, 1979

Selective expression of one Ca-2+-inhibitable adenylyl cyclase in dopaminergically innervated rat brain regions. Molecular Brain Research 22(1-4): 236-244, 1994

Selective expression of one Ca(2+)-inhibitable adenylyl cyclase in dopaminergically innervated rat brain regions. Brain Research. Molecular Brain Research 22(1-4): 236-244, 1994

Effect of chronic cocaine treatment on mu- and delta-opioid receptor mRNA levels in dopaminergically innervated brain regions. Journal of Neurochemistry 66(2): 443-448, 1996

Regional differences in the high affinity uptake or 3H-dopamine and 3H-norepinephrine in synaptosome rich homogenates of cat brain. Life Sciences 18(4): 411-418, 1976

Regional differences in the high affinity uptake of tritiated dopamine and tritiated norepinephrine in synaptosome rich homogenates of cat brain. Life Sciences 18(4): 411-418, 1976

beta-Carbolines: a tool for investigating structure-activity relationships of the high-affinity uptake of serotonin, noradrenaline, dopamine, GABA and choline into a synaptosome-rich fraction of various regions from rat brain. Journal of Neurochemistry 30(6): 1573-1578, 1978

DARPP-32, a dopamine- and adenosine 3':5'-monophosphate-regulated phosphoprotein enriched in dopamine-innervated brain regions. I. Regional and cellular distribution in the rat brain. Journal of Neuroscience 4(1): 84-98, 1984

Changes in the kinetics of [3H]dopamine release from median eminence and striatal synaptosomes during aging. Endocrinology 126(1): 228-234, 1990