For any independent, heterosexual woman, this news might be terrifying: semen contains a protein that could potentially be messing with your mind. Well, at least it’s messing with llama minds.
A recent study that was published online in PNAS (which if you sound out the journal name is very appropriate for this subject) found that a protein in llama semen, when injected into the female animal’s bloodstream, causes ovulation with no “physical activity” required. The responsible protein in the semen is one that they’ve known about for decades, called nerve growth factor, or NGF, but no one knew that it had these stimulatory powers. NGF is found in all sorts of animals and functions in the brain to keep neurons alive and kicking.
Researchers think that the NGF protein travels to the llama’s hypothalamus and pituitary gland in the brain and tells it to start pumping out the hormones that cause ovulation.
(Ok, so before I get into the nuts (ha!) and bolts of this post, I just have to point out that Greg Adams and his colleagues at the University of Saskatchewan collected semen using an “artificial llama vagina.” Can you imagine Adam’s grad students explaining that to their grandmothers when asked what they do in the lab? The llamas are lucky compared to the bulls in the experiment, however, whose semen was collected using “electroejaculation.”)
Fortunately for humans, llamas are “induced ovulators” which means that they only drop an egg when they have sex (or when a scientist doses it with semen extract). Humans and many other animals are “spontaneous ovulators” which is a misleading term for females that release eggs on a regular schedule.
While human women do not ovulate on command, it’s still possible that NGF is having an effect on a women’s cycle, and slightly altering the timing of ovulation. The researchers next step is to look at NGF in human couples. They think that the protein may play a role in fertility and want to see if men with low NGF have a hard time impregnating women.
In cows, at least (also spontaneous ovulators), NGF from regular doses of semen causes the female’s reproductive system to pump out higher levels of hormones that help the cow not to miscarry. If the same effect happens in humans, then couples should continue “baby dancing” even after the woman is pregnant.
All of this is still speculation in animals that are not llamas, camels, cows and mice, but NGF is found in the semen of ALL animals that scientists have examined, and in high concentrations. Contrary to “biology according to Todd Akin,” it’s likely that the presence of this protein in semen evolved to improve the odds of insemination.
Finally, the researchers also think that NGF may be one reason why the rhythm method is such an ineffective way of not getting pregnant. If NGF from sperm is altering a women’s cycle then it will be especially hard to track it and limit sex to “non-fertile” times. According to the Planned Parenthood website, one in four couples who practice the rhythm method will get pregnant each year.