Posted by SLS on January 4, 2012, at 1:48:02
In reply to Re: Adding Parnate and prazosin. » Phillipa, posted by SLS on January 4, 2012, at 1:18:25
This is an interesting abstract that reports a downregulation of NE alpha-1 (prazosin) binding with antidepressant use.
- Scott
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J Neural Transm. 2010 Dec;117(12):1423-30. Epub 2010 Dec 7.Differential modulation of a-1 adrenoceptor subtypes by antidepressants in the rat brain.
Ramakrishna D, Subhash MN.
SourceKamineni Institute of Medical Sciences, Sreepuram, Narketpally, Nalgonda 508254, Andhra Pradesh, India. drramakrishna@klsindia.com
AbstractThe aim of the present study was to examine the effect of chronic antidepressants treatment on the density of a1-adrenoceptor (AR) subtypes in rat brain. Density of total a1 and a(1A)- and a(1?)-ARs was measured in cortex and cerebellum of rats treated with amitriptyline (AMI), desipramine (DMI) and fluoxetine (FLX), (10 mg/kg body wt), for 30 days, using [³H]prazosin in presence and absence of WB-4101. The density of cortical total a1-ARs was significantly decreased with AMI (54%) and DMI (25%) treatment, without altering the affinity of the receptor. Fluoxetine did not alter the density of cortical a1-ARs. The density of cortical a(1A)-ARs was also significantly decreased with AMI (85%) and DMI (50%) treatment, without affecting the affinity. The density of cerebellar total a1-ARs was significantly decreased with AMI (37%), DMI (50%) and FLX (70%) treatment, without affecting the affinity for [³H]prazosin. The density of a(1A)-ARs was significantly decreased with AMI (67%), DMI (59%) and FLX (92%) treatment. a(1B)-AR density was decreased only with FLX (47%) and DMI (47%) treatment. Correspondingly the basal IP3 and NE (10 µM) stimulated IP3 levels were significantly decreased in AMI (47%), DMI (22%) and FLX (48%) treated rat cortex. The results suggest that chronic antidepressant (AD) treatment down-regulates the cortical and cerebellar total a1-ARs in rat brain. However, a(1A) subtype is predominantly down-regulated by AMI and DMI, where as FLX affects cerebellar a(1A)-ARs. The region-specific and subtype specific down-regulation of a1-ARs density, which occurs after prolonged AD treatment, may underline the therapeutic mechanism of action.
PMID:
21136124
[PubMed - indexed for MEDLINE]
Some see things as they are and ask why.
I dream of things that never were and ask why not.- George Bernard Shaw
poster:SLS
thread:1005781
URL: http://www.dr-bob.org/babble/20111226/msgs/1006283.html