Testicle Transplant

Dumb question, just something my friends and I wondered last night while drunk, and not even the physiology major in the group knew the answer…

If it was possible to transplant one man’s testicles into another’s scrotum, whose spermatzoa would end up being produced from then on, the donor’s or the recipient’s???

Er, well, the last biology I had was was back freshman year of high school, so this is a highly inexpert opinion. Not that that’ll stop me from giving it.

From what I recall, the process of sperm production can only work with the cells that are present there. In this case, that would be the cells of the, er, donor.

Like I said, this is just my best guess.

Why this would be done, I have no idea. The sperm would be those of the (hopefully deceased) donor.

I remember a case of two identical twins. One was sterile, so the other donated one of his testicles and later the recipient fathered a child. This is the only case I’ve ever heard of.

I’ve heard of another. My most recent ex-girlfriend is a urologist, and she told me this story which was told to her by a colleague who is a pediatric urologist (yes, they really specialize!). She didn’t name any names so I figure I can share it.

An infant boy was brought to my ex’s colleague with an undescended testicle. Whatever standard procedures are used to make testicles descend didn’t work in this case, so the doctor simply removed it so it wouldn’t become necrotic or cause other complications. After all, he had another one.

Twelve years later, the boy was brought back to the doctor after an injury which [wince]destroyed the remaining testicle[/wince]. Just in time for puberty! The father was distraught, and asked if a transplant would be possible.

“Well, no,” was the answer. It seems testicles (for whatever reason) are among the most immunogenic organs known to man (pun intended), so the donor would pretty much have to be an identical twin for it to be feasible.

The father brightened at this. “Can do!”

It turned out the boy was an identical twin! So his brother made a donation to the cause (after all, he had another one), and the boy’s teenage hormone angst party continued as scheduled.

I realize this doesn’t answer the OP, but it’s a great story, isn’t it? I’ve got seven months’ worth of stories like that.

When a testicle can’t be persuaded to desend, I’m wondering why removing it seems to be the thing automatically done. Yes, problems might develop with an internal testicle. But why not just leave it in place and keep a close eye on it? Remove it when and if problems develop. Esp. in cases where both testicles are internal. I’d think it would be better to leave them in place as long as possible, and let the patient develop as a normal male. And in cases where only one testicle is affected, well, five’s story illustrates that one can’t just assume that “one will be enough”.

To me, the situation seems similar to a woman from a family with a history of breast cancer. She’s at high risk of developing breast cancer. Medical science won’t recommend removing both breasts because they’re “likely to develop problems” – medical science just recommmends close monitoring. In general, close monitoring, vigilance, frequent testing are the recommendations for people at high risk of developing anything bad – why are internal testicles not looked at the same way?

Hazel:

Hazel, please remember the story was told by the attending doctor to my ex-girlfriend, then to me (a layman), and then to the board. I’m sure there were unique circumstances that justified removal of the testicle. The story I shared is the shorthand.

Okay, re the summary removal of internal testicles, I ammend my question from “why is that what they do?” to “IS that what they do, and if so, why?” And while I’m at, how do they try to externalize one?