It’s fair to say that biochemistry probably won’t be at the forefront of most people’s minds this Valentine’s Day. Whether it’s a day you embrace in all its pink, sugar-coated, love heart-shaped glory or ignore as a commercial and excessively saccharine money-making ploy by card manufacturers, thoughts of the chemical processes involved probably won’t feature.
But biochemistry is, of course, crucial.
A number of chemicals in the body are implicated in the process of falling in love. One of these is oxytocin. Often nicknamed the ‘love hormone’ or the ‘cuddle chemical’, oxytocin exerts very intriguing behavioural effects. Research has suggested that it has a role in bonding experiences such as childbirth, orgasm, the building of trust and falling in love. Conversely, a lack of oxytocin has been linked the display of psychopathic, narcissistic and manipulative tendencies.
It is thought that the biologically active form of oxytocin is its oxidised form; the octapeptide oxytocin disulphide. However it can also exist as the reduced dithiol nonapeptide oxytoceine. It has been suggested that the latter may also act as a free radical scavenger. In this way oxytoceine is then oxidized back to oxytocin via the redox potential of dehydroascorbate <—> ascorbate.
The structure of oxytocin is very similar to that of vasopressin, another hormone implicated in the process of falling in love. Oxytocin and vasopressin were isolated and synthesized by Vincent du Vigneaud in 1953, work for which he received the Nobel Prize in Chemistry in 1955.
Oxytocin has peripheral (hormonal) actions, and also has actions in the brain. These actions are mediated by specific, high-affinity oxytocin rhodopsin-type G-protein coupled receptors which require Mg2+ and cholesterol.
It is thought that oxytocin is released during a number of bonding processes. For example it is released by the hypothalamus gland during childbirth and also helps in the process of expressing breast milk. Perhaps more appropriate for Valentine’s Day, it is also released by both sexes during orgasm and it is thought that it promotes bonding when adults are intimate.
While oxytocin therapy may not be akin to a fairy-tale ‘love potion’, it does have a number of potential applications. It could be used in a variety of diverse scenarios from controlling prison riots to alcoholism to therapies for those with autism. Clearly the use of oxytocin raises a lot of ethical dilemmas. Sadly, whatever it is used for, it’s unlikely to help you to find the date of your dreams. (There go my Valentine’s Day plans…)
So this Valentine’s Day, in amongst all the roses and chocolate love hearts, spare a thought for the biochemical processes which may (or may not) be influencing your day.