Orgasm and Monoamines

[Oneiromancer]

I'm searching a reliable source discussing the long-term aftereffects of orgasm, or abstinence thereof, on dopamine levels. Some sources claim that orgasm decreases dopamine through prolactine for several weeks, but I've found no sources confirming this.

I'm also looking for research papers on the long-term effects of orgasm on serotonin and noradrenaline. I've found plenty of papers on the effects on hormones, but none on the more important monoamines.