Autor: |
Fraeyman N; Heymans Institute of Pharmacology, University of Gent Medical School, De Pintelaan 185, B-9000, Gent, Belgium. norbert.fraeyman@rug.ac.be, Vanscheeuwijck P, Wang JM, Huang Y, De Potter WP, Regan JW |
Jazyk: |
angličtina |
Zdroj: |
Brain research. Developmental brain research [Brain Res Dev Brain Res] 1999 Sep 06; Vol. 116 (2), pp. 127-32. |
DOI: |
10.1016/s0165-3806(99)00078-4 |
Abstrakt: |
The expression of presynaptic alpha(2)-adrenergic receptor (alpha(2)-AR) subtypes was investigated in cultured neurons from fetal pig superior cervical ganglion (SCG). Cells were incubated with chicken antibodies against alpha(2)A-, alpha(2)B- or alpha(2)C-AR subtypes either alone or together with antibodies against dopamine-beta-hydroxylase (DbetaH, a marker for adrenergic neurons) or against choline acetyl transferase (ChAT, a marker for cholinergic neurons). We found immunoreactivity for all three alpha(2)-AR subtypes in SCG-cells when cultured for 8-11 days. The relative expression of the alpha(2)A-subtype was approximately 1/3 of that of alpha(2)B- and alpha(2)C-AR. Co-localisation of all three alpha(2)-AR subtypes was observed in cells expressing DbetaH or ChAT. Increasing the potassium concentration in the culture medium increased the expression of DbetaH and decreased the expression of the alpha(2)A- and alpha(2)C-subtype without altering the expression of the alpha(2)B-subtype. Co-culture of neurons with pig splenocytes enhanced the expression of ChAT and decreased the expression of the alpha(2)B-subtype without altering the expression of alpha(2)A- and alpha(2)C-subtypes. Our results indicate that the three alpha(2)-receptor subtypes are expressed on both noradrenergic and cholinergic nerves. Induction of the noradrenergic phenotype favours the expression of the alpha(2)B-subtype over that of the alpha(2)A- and alpha(2)C-subtype. Conversely, enhancement of the cholinergic phenotype favours the expression of the alpha(2)A- and alpha(2)C-subtypes over that of the alpha(2)B-subtype. Our results suggest that the alpha(2)B-receptor is preferentially associated with noradrenergic nerve endings. |
Databáze: |
MEDLINE |
Externí odkaz: |
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