vasopressin and oxytocin?

Oxytocin (Greek: "quick birth") is a mammalian hormone that also acts as a neurotransmitter in the brain. In women, it is released mainly after distention of the cervix and vagina during labor, and after stimulation of the nipples, facilitating birth and breastfeeding, respectively. Oxytocin is released during orgasm in both sexes. In the brain, oxytocin is involved in social recognition and bonding, and might be involved in the formation of trust between people.

Vassopressin has nothing to do with bonding and acts the same way in males and females to help retain fluid.  It is released by the pitutiary and works primarily on the kidney - which helps to regulate blood pressure and water retention.  Vassopressin is also called ADH (Antidiuretic Hormone).

Fun fact... When people drink alcohol it inhibits the release of ADH and thats why folks have to pee a lot when they drink.

Regards,
Ryan

Actually, what Veg Ryan says is not exactly true. Both vasopressin and oxytocin have dual roles. Both are involved with basic physiological functions such as regulating blood pressure and thirst. However, they also act as neurotransmitters, influencing social behavior.

Oxytocin is released in both men and women in many social situations involving trust, friendship, parenting and the love for a partner.

Oxytocin has been proven to play a role in maternal behavior and monogamy in animals, particularly the prairie vole. It's generally assumed, but not demonstrated, that it plays a similar role in human bonding.

In humans, oxytocin has proven to increase feelings of trust among men.

Scientists are not sure about the role of vasopressin, but it definitely influences parental behavior in the male. In rodents, it increases the tendency to guard the nest and also to retrieve wandering pups.

They used to think that oxytocin influenced female bonding and vasopressin did the same for males, but more recent research, especially by Karen Bales at UC Davis, shows that it's more complicated than that.

One intriguing fact is that in humans during sex, oxytocin release peaks in women at orgasm. In men, oxytocin peaks during arousal, while vasopressin peaks at orgasm. (This could explain why women want to cuddle after sex, while men want to jump up and do something -- if they don't fall asleep.)