Public Release: 

Obesity, kidney genetics, erectile dysfunction among highlighted research at APS Meeting

American Physiological Society

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)

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About The American Physiological Society (APS) The American Physiological Society is one of the world's most prestigious organizations for physiological scientists. These researchers specialize in understanding the processes and functions by which animals live, and thus ultimately underlie human health and disease. Founded in 1887 the Bethesda, MD-based Society has more than 11,000 members and publishes 3,800 articles in its 14 peer-reviewed journals each year.

October 1 - 4, 2003
Radisson Riverfront Convention Center Augusta, GA

CONFERENCE OPENS
WED., OCTOBER 1, 2003
@ 9:00 AM EDT

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