A man's male hormones may ward off heart damage by helping
vessels around the heart regenerate, suggest Australian
researchers in a report posted January 13 in the Journal of
Experimental Medicine. While studies have shown that estrogen
helps blood vessels regenerate, both in the uterus after
menstruation and around the heart after wear and tear, little is
known about whether or not men make up for a lack of the female
hormone. Some researchers have theorized that this disparity
accounts for why men tend to suffer worse heart attacks more
often and earlier in life than women. However, Sieveking and
colleagues find that this trend may be due to a drop in
androgens, a collective term for male hormones, as men age.
Cells derived from the umbilical cord of a human male fetus
responded to androgens by moving and multiplying—activities
associated with new vessel growth. Furthermore, castrated mice,
which produced fewer androgens, fared poorly after the
researchers inflicted vessel damage intended to resemble injuri