http://www.sciencedaily.com/releases/2007/02/070207172019.htm
Just a few whiffs of a chemical found in male sweat is enough to
raise levels of the stress hormone cortisol in heterosexual women,
according to a new study by University of California, Berkeley,
scientists
..........
The team's work was inspired by previous studies by Wyart's
colleague Noam Sobel, associate professor of psychology at UC
Berkeley and director of the Berkeley Olfactory Research Program.
He found that the chemical androstadienone - a compound found in
male sweat and an additive in perfumes and colognes - changed mood,
sexual arousal, physiological arousal and brain activation in
women.
..........
Sweat has been the main focus of research on human pheromones, and
in fact, male underarm sweat has been shown to improve women's
moods and affect their secretion of luteinizing hormone, which is
normally involved in stimulating ovulation. Other studies have
shown that when female sweat is applied to the upper lip of other
women, these women respond by shifting their menstrual cycles
toward synchrony with the cycle of the woman from whom the sweat
was obtained.
Androstadienone, a derivative of testosterone that is found in high
concentration in male sweat, and in all other body secretions, has
garnered the most attention. However, though its effect on a
woman's mood, physiological arousal and brain activity suggests
that the chemical is a possible pheromone-like signal in humans,
its effect on hormone levels was unknown.
.........
In two trials, a total of 48 undergraduate women at UC Berkeley
were asked to take 20 sniffs from a bottle containing
androstadienone, which smells vaguely musky. Over a period of two
hours, the volunteers provided five saliva samples from which
cortisol levels were determined.
Compared to their response when sniffing a control odor (yeast),
the women who sniffed androstadienone reported an improved mood and
significantly higher sexual arousal, while their physiological
response, including blood pressure, heart rate and breathing, also
increased. This was consistent with previous studies.
.........