Going back into the archives I can see that Dr. Mariano posted this in the 2006-2007 time frame, but it is reference to the effect of TRT on dopamine not the AR. Keep in mind he is saying that this may be possible, it certainly doesn't happen in all men.
"Dopamine is one neurotransmitter that clearly can result in tolerance when present at high levels. Dopamine is a neurotransmitter that needs to vary in concentration hour by hour. On of its functions is to provide a feeling of reward on certain events. A reward cannot last forever, it has to have a finite life or one cannot differentiated it as a reward. TRT generally does not have the frequent fluctuations in dopamine level during the course of the day that natural testotserone production lends."
"Dopamine sensitivity improves once a deficit is created.
Going off TRT periodically, which is done by ASIH, for example, would then allow dopamine sensitivity to return."
"When total testosterone is supraphysiologic - i.e. over 1000 ng/dl - problems with libido and erections may occur. Testosterone increases dopamine in the brain in order to increase sex drive, reduce depression, give pleasure to activities. The problem is that dopamine is a very fragile neurotransmitter/hormone in its effects. Too high a dopamine level can cause tolerance to dopamine. This is similar to how one can develop tolerance to drugs such as cocaine and amphetamines which increase dopamine levels in the brain to cause their high. This can lead to the loss of libido when high testosterone levels are maintained for long periods of time."