One month oral therapy with calcium channel blockers caused significant (P < 0.001) decrease in serum levels of triiodothyronine and thyroxine and significant increase in serum levels of thyroid stimulating hormone in rabbits. Most probable mechanism of action was block in the synthesis and/or release of thyroid hormones.

We recorded an esophageal electrocardiogram in a rabbit before and after producing esophageal erosion. The erosion caused an increase in P wave and R wave height and inversion of the T wave. Esophageal erosion can thus cause false positive repolarization changes in the esophageal electrocardiogram.

We studied the effect of oral potassium supplement alone and with spironolactone on the lithium-induced T wave change in rabbits. T wave flattening produced by lithium was not affected by oral potassium supplementation. Oral spironolactone therapy effectively reverted as well as prevented lithium-induced T wave flattening.