You know, I tried to think up a clever title for this one, but I really think the straight talking just says it all. This really IS about applying pot (or at least, the active ingredient in pot) to bull semen. Ah, science.
Shahar and Bino. "In vitro effects of delta-9-tetrahgdrocannabinol (THC) on bull sperm" Biochemical pharmacology, 1974.
To start off, this paper is from the 1970's. The cannabinoid receptors did not get discovered or clarified until the 1980's. So the authors conducting this research at the time really had no idea how delta-9-tetrahydrocannabinol (delta-9-THC), the psychoactive ingredient in marijuana, was having its major effects. So you can't exactly fault them for pursuing the wrong line of inquiry, as I'm sure a lot of wrong lines were pursued until the right one was found (as is most often the case in science).
In this case, the author decided to focus on membranes. Delta-9-THC is known to be highly lipophilic (meaning it loves lipids). Most people know of lipids as having to do with fats, but lipids play a very important role in the cell membrane. In that they ARE the cell membrane. They also make up the membranes of mitochondria, the organelles in our cells that provide the energy for cell function. So if delta-9-THC is lipohpilic, the idea is that it would interact with membranes. Like those in your cell membranes or mitochondria, and if this was the case, it might disrupt the functions of those membranes or organelles.
The authors wants to test the effects of delta-9-THC on mitochondria in particular. For this, they got bull semen. Why bull semen? Well, because sperm are made like this:
You can see at the head (hehehe, sperm. Head. I need to grow up) the package of DNA, but what powers the sperm in its little swimming journey is the pile of mitochondria at the beginning of the tail. These mitochondria produce lots of ATP, the energy currency of the cell, which powers the whip-like motions of the sperm tail and allows it to head off on its merry way. So if you want to study the effects of delta-9-THC on the membranes of mitochondria, sperm are actually a pretty good choice. Lots of mitochondria, and they all do one thing: push that sperm ONWARD. So you can look at membranes of the mitochondria, and see how functionally disrupted the sperm are by checking how they swim afterward.
And why bull sperm? Because you can get it by mail order.
Yes. you can. (Nothing says classy like Bull-Elite! For all your bull sperm needs!)
Of course this was in the age before the internet so I imagine they used a catalog. Most major bovine producing operations use artificial insemination, and this means that you can buy bull sperm on the internet. Who wouldn't want to buy bull sperm on the internet, right??
Anyway, the authors obtained bull semen via mail order, diluted the semen and spun it down carefully to get the sperm separated. They then added various concentrations of delta-9-THC (0.03-0.3 millimolar, or 0.03-0.3 thousandths of a mole per liter) to the sperm.
At the lowest concentrations, the sperm retained motility, but began to show decreases in oxygen uptake. But as the dose began to get higher (higher doses of delta-9-THC, you see what I did there), the sperm stopped moving, and the mitochondrial areas of the tails began to swell. When they looked with a scanning electron microscope, they say changes in the mitochondrial "helix", the area where the mitochrondria concentrate.
The data are clear.
These findings indicate that THC has a pronounced effect on fresh bull sperm.
In other words, be careful when applying high doses of pot your bull sperm.
Does this mean anything for how delta-9-THC might affect YOUR sperm? Probably not. And it doesn't address the actual mechanism of delta-9-THC's psychoactive effects (which occur primarily because of delta-9-THC being an agonist at cannabinoid receptors). But they do let us know that high levels of pot could harm your bull sperm! Bull-Elite, take note!
Shahar A, & Bino T (1974). In vitro effects of delta9 tetrahydrocannabinol (THC) on bull sperm. Biochemical pharmacology, 23 (8), 1341-2 PMID: 4824778
PS: The talk of buying bull semen on the internet started a fabulous conversation on twitter last night. I just had to share it with you all.