A recent query from a gentleman in California sent us on a rather interesting chase here: he was looking for confirmation of a story he'd heard, that cacti were under cultivation at UOMS in the 1960s in specially designed greenhouses, the subjects of research for heart therapy drugs. Since researchers here have been delving into the mysteries of the heart (medically speaking) for half a century or more, there was an overabundance of unindexed information that may have yielded clues. We have annual reports from the Heart Research Laboratory, lists of faculty publications, biographical and subject files, all of which were cursorily searched for mention of cacti.
So, I contacted Space Planning. They revealed that there were greenhouses on top of Mackenzie Hall in the 1950s and 1960s (later removed) which can be seen in some aerial photographs from the period. Of course, you can't tell what's growing inside.
So, I decided to move methodically through the publications of any pharmacologists or cardiologists on the faculty in the 1960s. I didn't have to go far down the list: Elton McCawley and H. Lenox H.J. Dick (yes, that's all just one name) did research on several plant derivatives and their effects on the heart--nothing I recognized as cactus-based, but certainly enough to assume that if anyone was cultivating succulents for heart research here, they would have known about it.
Dr. McCawley passed away in 2002, but Dr. Dick may yet be able to reveal the answer to this question...
As a side note to the search for information on UOMS-based cactus research, I discovered that cacti and cardiology go way back: the National Library of Medicine's IndexCat has entries for studies on the use of cactus derivatives in heart medicine dating back to 1883.