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Donna Krupa
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Sex Differences in Osmotic
Regulation of AVP and Renal Sodium Handling
Report Among the Highlighted
Topics on Gender Differences in the October Edition of the Journal of
Applied Physiology
BETHESDA, Md. -- October 18, 2001 -- The American Physiological
Society (APS) kicks off a special series entitled, “Highlighted Topics on
Gender Differences in Physiology,” beginning with the October 2001 edition
of the Journal of Applied Physiology, the Society’s flagship
publication. The October issue offers the following examination:
Sex Differences in Osmotic Regulation
of AVP and Renal Sodium Handling
"Sex Differences in Osmotic Regulation of AVP and Renal Sodium Handling,"
is the highlighted mini-review of
Nina S. Stachenfeld, Andres E. Splenser, Wendy L. Calzone, Matthew P.
Taylor, and David L. Keefe from The John B. Pierce
Laboratory and Departments of Epidemiology and Public Health, Yale
University School of Medicine, and Women and Infants Hospital, Brown
University School of Medicine. The authors address sex hormone effects on
the regulation of body fluids and blood pressure.
In addition to the role of sex hormones in reproduction, they also have
an important effect on other physiological systems, which may explain
differences in disease progression between men and women. The mechanisms
underlying gender differences in blood pressure regulation remain unknown
but may include differences in body water and sodium regulation. Both
estrogen and testosterone receptors are present in the hypothalamus of adult
primates and thereby may alter cardiovascular regulation through changes in
fluid and sodium balance. In this study, the investigators focused on sex
hormone effects specifically related to hypothalamic osmotic regulation of
arginine vasopressin (AVP) during hypertonic saline infusion. In response to
hypertonic saline infusion, overall body fluid balance is similar between
men and women.
Results and Conclusions
However, these investigators found that men had greater plasma AVP
sensitivity to an increase in plasma osmolality induced by hypertonic saline
infusion, which was associated with an increase in systolic pressure, pulse
pressure, plasma cortisol levels, and sodium retention. The mechanism
underlying the increased blood pressure and sodium retention observed in men
was not clear from the data presented, but these observations indicate a
shift in the pressure-natriuresis curve related to differential sensitivity
to the renin-angtiotensin system or possibly direct effects on the kidney.
In addition, the greater AVP sensitivity to osmotic stimulation may have
also caused the greater increase in cortisol and blood pressure during
infusion. These findings suggest that a greater osmotic AVP sensitivity may
play a role in the greater cardiovascular morbidity in men compared with
women.
-end-
The American Physiological
Society (APS) was founded in 1887 to foster basic and applied science, much
of it relating to human health. The Bethesda, MD-based Society has more than
10,000 members and publishes 3,800 articles in its 14 peer-reviewed journals
every year.
***
Editor’s Note: To receive a copy of the abstracts, to interview speakers or
for more information, contact Donna Krupa at 703.527.7357(direct dial),
703.967.2751 (cell) or djkrupa1@aol.com.
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