AUGUSTA, Ga. Nearly 40 percent of the small adrenal tumors that cause big problems with high blood pressure share a genetic mutation that causes patients to retain too much sodium, researchers report.
The study of 47 human, benign adrenal gland tumors also showed a mutation of the gene KCNJ5 is twice as likely to occur in women 71 versus 29 percent as it points to potential new treatments for some patients who don't respond to current hypertension regimens, said Dr. William E. Rainey, Scientific Director of the Adrenal Center at Georgia Health Sciences University.
Addititionally, when scientists put the mutated gene into an adrenal cell, it immediately starts producing the sodium-retaining hormone aldosterone. "We found it turned on a whole series of genes that cause the cell to produce aldosterone," Rainey said.
Typically, KCNJ5 appears to help normalize levels of the sodium-retaining hormone aldosterone by regulating how much potassium is pumped in and out of aldosterone-producing cells on the outer layer of the adrenal glands. Abnormal protein produced by the mutated gene alters the cells' electrical status.
"When this gene has a mutation, the cells lose control and just start producing aldosterone all the time," said Rainey, corresponding author of the study in the Journal of Clinical Endocrinology and Metabolism.
"The combination of too much salt and too much of this hormone leads to high blood pressure and tissue damage," said Rainey. He notes that the vast majority of the 311 million Americans consume too much salt, even if they never pick up a salt shaker, because of high content in breads, processed and fast foods and the like. An estimated 33 percent of Americans are hypertensive and an estimated 1 in 10 have adrenal problems as the cause.
A 2011 study led by Yale University and published in the journal Science showed that the tumors had a KCNJ5 mutation. GHSU researchers, along wit
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Georgia Health Sciences University