Second degree AV block and severely impaired contractility in cardiac myxedema: a case report.

The heart is a major target organ for thyroid hormone action. Severe overt hypothyroidism can result in diastolic hypertension, lowered cardiac output, impaired left ventricular contractility and diastolic relaxation, pericardial effusion and bradycardia. However, the function of the atrial pacemaker is usually normal and the degree by which the heart rate slows down is often modest.

Endothelin type A and B receptors in the control of afferent and efferent arterioles in mice.

Background: Endothelin 1 contributes to renal blood flow control and pathogenesis of kidney diseases. The differential effects, however, of endothelin 1 (ET-1) on afferent (AA) and efferent arterioles (EA) remain to be established.

Methods: We investigated endothelin type A and B receptor (ETA-R, ETB-R) functions in the control of AA and EA.