Effect of propranolol and metoprolol on parathyroid hormone and calcitonin secretions in uraemic patients

Nine uraemic patients not being treated by dialysis received intravenous propranolol 1 µg/kg/min for 85 minutes after a priming dose of 1 mg. Fifteen days later, six of them received intravenous metoprolol 1·2 µg/kg/min after a priming dose of 1·2 mg. Plasma concentrations of parathyroid hormone (PTH) and calcitonin fell significantly after propranolol but not after metoprolol, whereas no change in plasma concentrations of ionised calcium and phosphate occurred with either drug. Heart rate fell similarly with both drugs. The fact that propranolol acutely suppressed PTH and calcitonin secretion in uraemic patients indicates that further studies are warranted to assess the long-term effects of the drug on the secretion of these hormones and on renal osteodystrophy. The contrast between the responses to propranolol and metoprolol supports the concept that PTH and calcitonin secretion is modulated through specific beta₂-receptors.