I spent the morning (before coffee, even) jabbing Testosterone into my butt with a 2.5 cm needle. (Some things coffee just doesn’t help.) It got me thinking.
I know the Insulin is a hormone and it used to be harvested from beef cattle. I know some bodybuilders take what is supposed to be Gorilla Growth Hormone. I know Testosterone is common amongst the mammals.
So are all hormones more-or-less species independent? Are some species-specific?
(Ah, the drugs are taking hold! Anyone want to fight?)
Basically, the closer on the evolutionary tree two species are, the more similar their hormones are gonna be. Testosterone is pretty universal among mammals, and I think insulin is as well, but beyond that, I’ll defer to the biologists.
Surprisingly in fact, they can be pretty far apart. For example, for therapeutic purposes, calcitonin (a peptide hormone of uncertain importance in normal bone and calcium homeostasis) of salmon origin is employed. The main reason is that salmon calcitonin is more potent than its human counterpart! (and also has a longer half-lfe).
The inter-species action of exendin is nothing short of amazing. Exendin is a lizard-derived peptide hormone having potent action on human glucose metabolism and gut function/motility. In fact, it has structural and biologic similarity to another human hormone called GLP-1
I guess what I’m trying to say (and doing such a lousy job of) is that evolutionarily remote organisms can have near identical peptide hormones and function. Ultimately this phenomenon arises because of an extremely “vigilant” preservation of the primary structure (and/or agonist effect) of the hormone. Some of these hormones’ primary structure has been pretty well preserved all the way from insects to humans!
I wonder how they make testosterone? I presume from recombinant human DNA? How does that work?
I don’t know how they make testosterone specifically, but if you’d like to make your own handy-dandy recombinant hormone, first isolate the (human) gene for it. Make tons of copies of it (using PCR, which lets you make millions of copies of a relatively short piece of DNA in a couple of hours.) Put those into a little ring of DNA called a plasmid, then transfer the plasmids into bacteria (E. coli is popular.) Grow the bacteria up in huge vats, and extract your hormone. (Obviously this is majorly oversimplifying things, but that’s the basic outline.)
There can be plenty of problems with this process. For example, proteins need to fold up in a particular way to work properly, and they might not do that inside bacterial cells, as bacteria don’t have a separate system of protein production for export like mammalian cells do. Many proteins also get accessorized with other molecules, like sugars, and bacteria don’t have the proper enzymes to act as stylists. Sometimes it’s just cheaper/easier to isolate your hormone from somewhere else - Premarin, the leading estrogen on the market, is isolated from mares’ urine. (Yum!)