Of Immune Systems, the VNO and Peptides

[belgareth]

The Sexy, Healthy Scent of

a Man

By Robert Roy

Britt
LiveScience Senior Writer
posted: 04 November 2004

The scent of a man, at least among mice, can reveal the state of his health and determine whether a female

gets pregnant, a new study shows.
The research suggests that other

animals, perhaps even you, choose mates in part based on the strength of their immune

systems.
Previous research had shown mice prefer to breed with mates

whose immune-system genes -- which produce chemicals that help the body fight invading cells -- are different from

their own. Such selective sex leads to healthier offspring.
The new

study shows how the selection occurs.
Researchers at the University of

Maryland examined molecules known as peptides that come from the immune system and end up in urine. Each mouse's

disease-fighting peptides are unique, like fingerprints. A female records and remembers the scent of a mate's

peptides using its vomeronasal organ, inside the nose.
"Exposure,

during a critical period, to urine odor from another male, will prevent embryo implantation, leading to loss of

pregnancy, while exposure to the familiar odor will not," said Frank Zufall of the university's School of Medicine.


Spiking the punch
"We can

trick this odor memory and the outcome of the pregnancy-block test by adding peptides to urine," Zufall told

LiveScience. "In other words, we can switch an unfamiliar urine odor to a familiar one (and vice versa) by spiking

the urine with only a few peptides."
Other studies have shown that

vomeronasal organs in many animals detect pheromones and other molecules that pack information on sexual and social

status. Pheromones were first discovered in the 1950s to be sex attractants in

insects.
"We believe that detection of [immune system] peptides via the

nose may be of general significance for social behaviors in all vertebrates," Zufall

said.
The study was led by Trese Leinders-Zufall and will be detailed

in the Nov. 5 issue of the journal Science.
Picky,

picky
Similar peptides exist in human immune systems. But our

vomeronasal organ has apparently been rendered defunct by evolution, many scientists believe, though there's some

uncertainty about this. In fact the question of how and whether scent affects a woman has been widely debated in

recent years.
Since discovering powerful sex pheremones in silkworms

decades ago, scientists have been hot to learn whether humans could be similarly stimulated. The investigation has

proved frustrating.
"Compared to insects, whose behavior is stereotyped

and highly predictable, mammals are independent, ornery, complex creatures," notes writer Maya Pines of the Howard

Hughes Medical Institute.
Like any animal, we humans are picky. And

that provides a line of investigation.
Stinky

T-shirts
In 1996, Claus Wedekind, a zoologist at Bern University in

Switzerland, conducted what's become known as the stinky T-shirt study. Wedekind had 44 men each wear a t-shirt for

two nights straight, then tested how women reacted to the smelly shirts.
Like mice, women preferred the scent of men whose immune systems were unlike their own. If a man's immune

system was similar, a woman tended to describe his T-shirt as smelling like her father or

brother.
Since then, companies have developed pheremone-based perfumes

and cologns, with promises of increased sexual attraction. Researchers don't agree on their effectiveness.


More research is needed to figure out how and to what extent a

woman's nose leads her to sex, and how adept she is at picking a healthy partner.
"We cannot rule out that other parts of the human nose are able to detect the peptides," Frank Zufall

said. "We can now ask whether these peptides are present in human secretions such as sweat and saliva, whether they

can be detected by the human nose, and if so, whether they have any influence on our own social behavior."



The article and further

info can be found here:

http://www.livescience.com/humanbiology/041

104_sex_and_smell.html

[Lor]

what are the implications of

tricking the vno into thinking your a healthy choice for offspring?
(great implications if your using

condoms,lol.) im not stupid, im slow...and genuinely interested lol.

"Exposure, during a critical period, to urine odor from another male, will prevent

embryo implantation, leading to loss of pregnancy, while exposure to the familiar odor will not," said Frank Zufall

of the university's School of Medicine.

so......
infertility treatments. but what if

the reasons for miscarraige are genetic/abnormalities? like i said, be patient with me,im slow

[belgareth]

Frankly, I have no idea. All I

did was post an interesting article.

[CptKipling]

Thanks Bel, good article.