Investigators examined nasal microvasculature in one of the volunteers after a vasoconstrictor challenge with 100 mg of cocaine, which is routinely used as a local anesthetic and vasoconstrictor by ear, nose, and throat specialists, the authors noted. The challenge resulted in transient cessation of microcirculatory flow.
"We're kind of glad they didn't do the same thing with the reindeer, because the last thing we would want is reindeer on cocaine, pulling Santa around the sky," said Cullen.
After administration of medetomidine anesthesia, the investigators performed similar evaluations of the reindeer nasal mucosa. They found an abundant microcirculation carrying a heavy concentration of red cells. Mean perfused vessel density was 20, as compared with 15 in the human volunteers.
The authors also evaluated the reindeer nasal microcirculation after the animals completed a treadmill test, which showed that "they do indeed have red noses. In addition to the nose having a high microvascular density, the nasal mucosa also revealed an abundance of ring-like vascular arrangements, similar to those in humans."
The study does not completely resolve questions surrounding the origin of Rudolph's red nose, according to Cullen. Noting that many human's noses turn red during alcohol consumption, he said the role of alcohol in Rudolph's bright red nose remains to be seen.
"It would have been interesting to see if giving the reindeer alcohol would have caused their noses to be redder and increased the blood flow," said Cullen.
If alcohol does play a role in the color of Rudolph's nose, the study has implications that extend beyond well beyond a single reindeer.
"I think [the message] will be 'Don't let Santa drive drunk,' because he won't be able to deliver the presents," said Cullen.
"Seriously, a lot of people leave out quick drinks for Santa and carrots for the reindeer, so I think maybe we should stick to healthier food and drink for both Santa and the reindeer."