Posted by undopaminergic on March 27, 2008, at 3:58:20
In reply to Re: High blood pressure on Selegiline! » undopaminergic, posted by Amigan on March 26, 2008, at 16:05:08
> > Interestingly, the EMSAM prescribing information suggests that selegiline is an alpha2B-agonist.
> Never heard of it before. I don't even know what this means.
It means that selegiline can stimulate one of the three known subtypes of alpha2-adrenoceptor. The A subtype is the one relevant for lowering BP, regulating noradrenaline release (autoreceptor) and enhancing spatial working memory, and also functions as a presynaptic receptor on at least some serotonergic and glutamatergic terminals. I don't have a good understanding of what the B and C subtypes do, and they appear to be much less common. However, the B-type may play a role in regulating pupil size - have you noticed any effect of selegiline on your pupils? I've seen a clear tendency to a reduction.
> I use to think that selegiline could cause hypertension due to its "catecholamine-enhancing" properties. NE enhancing in this case. I mean, Dopamine alone, can even cause a drop in blood pressure, which is consistent with what you posted earlier in this thread.
Yes. The relative contributions of MAO-B inhibition (ie. phenylethylamine) and selegiline and its metabolites remain an interesting question. Could the cardiovascular effects be avoided by replacing selegiline with rasagiline? Last time I checked, there were no reports on the matter except as regards anaesthetised rats and very high doses (incidentally co-authored by the inventor of rasagiline).