From EurekAlert!:

New research by a team of scientists at the University of Cincinnati (UC) shows that bisphenol A (BPA) may be harmful for the heart, particularly in women.

Results of several studies are being presented in Washington, D.C., at ENDO 09, the Endocrine Society's annual meeting, June 10-13.

A research team lead by Scott Belcher, PhD, Hong Sheng Wang, PhD, and Jo El Schultz, PhD, in the department of pharmacology and cell biophysics, found that exposure to BPA and/or estrogen causes abnormal activity in hearts of female rats and mice.

In addition, these researchers found that estrogen receptors are responsible for this affect in heart muscle cells.

BPA, an environmental pollutant with estrogen activity, is used to make hard, clear plastic and is common in many food product containers. It has been linked to neurological defects, diabetes and breast and prostate cancer.

Using live cultures of cells isolated from rat or mouse hearts, researchers briefly exposed the cardiac cells to BPA and/or estrogen. Both compounds caused striking changes in the activity of cardiac muscle cells from females but not males. Additional studies revealed that these cellular changes in activity caused improperly controlled beating in the female heart.

"Low doses of BPA markedly increased the frequency of arrhythmic events," Belcher says. "The effect of BPA on these cardiac arrhythmias was amplified when exposed to estradiol, the major estrogen hormone in humans."

The mechanism underlying this harmful effect was investigated using cellular imaging techniques.

"BPA and/or estrogen rapidly stimulated contraction by altering control of the concentrations of free calcium inside the heart cell but only in heart muscle cells from females, showing that these effects were sex-specific," Belcher says. "BPA's presence increased the frequency of calcium 'sparks' from the sarcoplasmic reticulum—the part of the cardiac muscle that stores and releases calcium ions—indicating spontaneous release or 'leak' that's likely causing the heart arrhythmias and may have other harmful actions, especially following heart attack."

Belcher and colleagues also investigated the nature of the mechanisms that mediated the responses of the cardiac muscle cells to estrogen and BPA.

"Pharmacological studies using selective estrogen receptor drugs and animal models lacking estrogen receptors were used to investigate the role of each estrogen receptor in mediating the rapid sex-specific function effects of E2 and BPA in cells," he says. "Our findings suggest that estrogen has opposing actions in cardiac cells.

"In female cardiac muscle cells, the blocking or genetic removal of estrogen receptor beta completely blocked the contractile effects of BPA and estrogen, while in males, blockade of the effects of estrogen receptor alpha caused the male heart to become more 'female-like' and become responsive to estrogen and BPA.

"These studies have identified new and important potential cardiac risks associated with BPA exposure that may be especially important for women's heart health," he says.

UPDATED

From HealthDay:

A U.S. Food and Drug Administration advisory panel voted overwhelmingly Wednesday that Seroquel and Zyprexa, two powerful antipsychotic drugs, be approved to treat schizophrenia and bipolar disorder in children aged 13 to 17.

The panel also endorsed Geodon, a third antipsychotic in the same class, as safe and effective for the treatment of bipolar mania in children aged 10 to 17.

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From The Associated Press:

Advisers to the Food and Drug Administration are scheduled to vote Wednesday on whether three powerful psychiatric drugs should be approved for children, despite side effects that can increase the risk of diabetes.

A positive decision from FDA would expand the use of a class of drugs that accounted for more than $14.6 billion in sales last year, according to health care analysis firm IMS Health.

The FDA will ask its panel of psychiatric experts whether drugs from AstraZeneca PLC, Eli Lilly & Co. and Pfizer Inc. should be approved to treat schizophrenia and bipolar disorder in patients ages 10 to 17. The drugs already are approved to treat those conditions in adults.

On Tuesday, the companies each presented data from studies that lasted between three and six weeks and compared their drugs to placebo.

FDA officials told panelists the drugs appear to be effective for younger patients, though concerns remain about their side effects, including weight gain, high blood sugar and sleepiness.

Patient and consumer groups said the companies should have conducted more in-depth studies to look at the long-term effects of the medications.

The FDA on Wednesday will ask the 10 members of its psychiatric drug advisory committee to discuss the benefits and risks of each medication and then vote on whether it should be approved for younger patients.

The FDA is not required to follow the advice of its panels, though it usually does.

AstraZeneca and Lilly are seeking permission to market their drugs — Seroquel and Zyprexa, respectively — for adolescents with schizophrenia and bipolar mania, also called manic depressive disorder. Pfizer is seeking approval to market its pill Geodon for bipolar patients ages 10 to 17.

With only two anti-psychotic drugs currently approved for younger patients, a positive decision for the three drugs would significantly increase competition in the market for anti-psychotics — the top-selling class of prescription medications in the U.S. last year, according to IMS Health.

Currently, only Bristol-Myers Squibb's Abilify and Johnson & Johnson's Risperdal are approved for use in younger patients.