Sunday, February 18, 2007
Hello! As we learnt in one of the earlier entries, humans with high levels oxytocin are calmer and more social. What about in animals? Do oxytocin affect animals in the same way? That's what we are going to find out today.
Oxytocin in animals
Animals with high levels of oxytocin are calmer, more relaxed, more social and less anxious. In several animal species, oxytocin leads to maternal behavior and to affiliation.
These are some of the uses of oxytocin in animals:
- The primary use of oxytocin is to induce labor in animals having weak or no contractions. The drug enhances uterine contractions at the time of fetal delivery.
- Oxytocin is also used medically to expel any residual placental material that might be left in the uterus, preventing the subsequent development of metritis
- Oxytocin helps to stimulate milk release after delivery.
For example, mice that are unable to secrete oxytocin due to targeted disruptions of the oxytocin gene will show deficits in milk ejection and have subtle derangements in social behaviour.
Here are some studies involving oxytocin in mammals:
In a study published in the Proceedings of the National Academy of Sciences, researchers used mice to show that oxytocin’s receptor may also facilitate the formation of trust demonstrated through social bonding. The hormone uses a receptor to bind to a cell and perform its duties.
The results showed that male and female mice that lacked the oxytocin receptor had problems forming trust and establishing normal social relationships. For example, female mice lacking the oxytocin receptor had impaired nurturing abilities and were slow to retrieve their pups when they wandered off. Male mice lacking the receptor tended to be more aggressive toward other males and had "social amnesia" when reintroduced to a female. The males also had less vocalized calls and a greater tendency to move around and explore.
In another series of studies in mice-like animals, known as prairie voles, which have a penchant for monogamy (having only one ‘love’ partner), indicate that oxytocin, as well as another hormone called vasopressin, are important for social attachment. For example, researchers found that supplements of either one of these hormones increase the voles' social contact with other voles and their development of a preference for a familiar partner. When voles receive a compound that blocks the activity of either hormone, supplements of the hormones do not create any partner preference and social contact is low.
What about in other animals?
Cattles
If you want to obtain trivial amounts of milk from animals like dairy cattle, you have to stimulate oxytocin release because around 80% of the milk is available only after ejection, and milk ejection requires oxytocin. Watch someone milk a cow, even with a machine, and what you'll see is that prior to milking, the teats and lower udder are washed gently - this tactile stimulation leads to oxytocin release and milk ejection.
Dogs
Oxytocin is used in cases when you suspect that your dog starts to get fatigued or that there is a uterine atonia, which can be derived from tiredness or the lack of muscular tone. But its administration must be very meditated and rigorously controlled, always keeping note of how much you have administered, depending on the size and weight of the dog. In any case, you should proceed if the dog has not had the uterine dilatation, either by natural means or by the administration of a certain amount of a uterine dilator. If you administer oxytocin before the first birth, it can rupture the uterus, with irreparable consequences like the death of the female dog. =x
(http://www.petplace.com/drug-library/oxytocin/page1.aspx)
(http://arbl.cvmbs.colostate.edu/hbooks/pathphys/endocrine/hypopit/oxytocin.html)
Wow, looks like oxytocin plays a really important role in animals, just like how they do in humans!
