Obesity, kidney genetics, erectile dysfunction among highlighted
research at APS Meeting
September
22, 2003 – (Bethesda, MD) – Our heart, blood pressure and
kidneys are essential for life, and the healthy interplay among
them is key to good health. But high blood pressure
(hypertension) can make the heart and blood vessels work harder
and stresses the kidneys, which leads to a variety of
cardiovascular and kidney diseases.
African-Americans are known to have disproportionately higher
rates of elevated blood pressure compared to the rest of the
U.S. population. These higher blood pressure rates also cause a
number of kidney related health problems. Genetics may be the
reason African-Americans aged 25-44 are 20 times more likely
than their white counterparts to develop hypertension-related
kidney failure.
Every body
issues instructions to the heart, the blood vessels and the
kidneys about what to do. Our individual genetic code, the
individual proteins that create the genes, and the external
environment in which we live combine to shape the instructions.
Understanding the mechanisms dictating how these factors operate
individually -- and their interplay among one another -- is the
focus of research that will ultimately improve our understanding
of human health and disease.
It is also
the purpose of the upcoming fall meeting of the American
Physiological Society (APS) (http://www.the-aps.org),
being held October 1-4, 2003 at the Radisson Riverfront Hotel,
Augusta, GA Research highlights of the meeting, entitled,
Understanding Renal and Cardiovascular Function Through
Physiological Genomics, include:
HEALTH
AND RACE
Racial Differences in Stress-Induced Salt Sensitivity and
Resulting Blood Pressure Load Researchers have tested their
hypothesis that stress is a contributing factor to
African-American health status through an effect on the kidneys
via pressure natriuresis (the excretion of sodium in urine,
usually in excessive amounts). They report on their protocol
involving 189 African-American (AA) and 32 Caucasian Americans
(CA) 15-18 years of age which found that the AA group had lower
urinary natriuresis volume during stress, despite similar levels
of systolic blood pressure. The study also found that the blood
pressure of AA participants was significantly higher two hours
following the cessation of the stressor. (Dr. Harshfield/Friday
PM)
Association Between Protein and Blood Pressure in White Females:
The Twins' Study The genetic defects of a protein subunit gene
(GNB3) have recently been highlighted as a determinant of
hypertension. A examination of 141 fraternal Caucasian female
twins finds supporting evidence that a GNB-related allele may be
a risk factor for hypertension in Caucasian females. (Dr.
Dong/Friday PM)
OBESITY
COX-2 Inhibitors May Be Beneficial for Preventing Renal Damage
in Obesity-Related Type II Diabetes Obesity is a major risk
factor that, along with hypertension and hyperglycemia,
contributes to the progression of kidney disease. A new study
with an animal model finds that during development of
obesity-related diabetes, alterations in COX-2 derived
metabolites may contribute to the renal damage associated with
this disease. Taken as a whole, this suggest that COX-2
inhibitors may be beneficial for preventing renal damage in
obesity-related Type II diabetes. (Dr. Dey/Friday PM)
Eicosanoids and a High-Fat Diet
The exact mechanisms by which obesity causes hypertension are
not fully understood, but has been linked to the kidneys. That's
because the kidneys play a key role in regulating blood
pressure, and substances, which affect renal salt and water
excretion, are important modulators of hypertension. Cytochrome
P450 (CYP) enzymes metabolize the fatty acid arachidonic acid
into different metabolites ("eicosanoids") in the kidneys can
metabolize the fatty acid. Eicosanoids have been shown to cause
constriction or dilation of the blood vessels, and affect the
basic function of kidneys. A new study suggests that decreased
synthesis of eicosanoids during a high fat diet impacts the
regulation of renal function and blood pressure. This knowledge
may ultimately help uncover new therapeutic targets for the
control and treatment of obesity-induced hypertension. (Dr.
Wang/Thursday PM)
ED AND
PKC: MORE ON ERECTILE DYSFUNCTION
Type II diabetes is a major risk factor for erectile
dysfunction, although the exact mechanism(s) are not yet known.
A new study reports that the protein kinase C (PKC) may
contribute to the vasoconstriction of the penis' circulation,
thereby reducing the erectile response, in obese, diabetic rats.
(Dr. Wingard/Thursday PM)
GENETICS AND KIDNEY CANCER
Kidney cancer affects over 32,000 Americans annually and is
responsible for nearly 12,000 deaths each year. Kidney cancer is
made up of a number of different types of cancers, each with a
different pattern, and can be caused by different genes. There
are four types of inherited kidney cancer; among them is Von
Hippel Lindau, an inherited form where patients are at risk for
developing tumors in the kidneys, brain, spine, and eyes. W.
Marston Linehan, MD, Urologic Oncology Branch of the National
Cancer Institute, is presenting a current review of inherited
forms of kidney cancer.
(Dr. Linehan/Thursday AM)
GENE
PROFILES OF CHRONIC KIDNEY DISEASE (CKD)
Chronic kidney disease (CKD) has become more widely known this
year after the announcement that it took the life of the
velvet-voice, two-time Grammy winning singer, Barry White, at
age 58. Edwin Bottinger, MD, associate professor of medicine and
molecular genetics at the Albert Einstein College of Medicine,
and director of the Einstein Biotechnology Center reports on the
state of knowledge for genetically profiling the disease. (Dr.
Bottinger, Saturday AM)
GENES
RESPONSIBLE FOR THE SALT-SENSITIVITY OF BLOOD PRESSURE FOUND TO
LIE IN SAME REGION AS GENES RESPONSIBLE FOR RENAL DAMAGE
Results of a study indicate that the genes responsible for the
salt-sensitivity of blood pressure lie in the same region as the
genes responsible for renal damage providing evidence for a
genetic link between these problems. (Dr. Moreno, Friday PM)
ESRD:
THE MOST FEARED CONSEQUENCE OF KIDNEY DISEASE. WHAT'S THE
RELATIONSHIP TO GENETICS?
Some forms of kidney cancer which lead to end-stage renal
disease (ESRD) – when the kidneys permanently fail to work --
are caused by genetic defects. Increasing evidence also points
to that inherited factors that influence the risk of developing
diabetic or hypertensive ESRD. Howard J. Jacob, Ph.D. of the
Medical College of Wisconsin oversees clinical programs with
over 30,000 participants for renal studies and discusses the
status of understanding the genetic basis of the disease ESRD,
the most feared consequence of kidney disease. (Dr. Jacob,
Friday AM)
Source:
American Physiological Society
