atrial-natriuretic-factor and Hypercalcemia

Topics: Atrial Natriuretic Factor; Cardiotonic Agents; Diphosphonates; Equipment Reuse; Heart Failure; Humans; Hypercalcemia; Imidazoles; Natriuretic Peptide, Brain; Neoplasms; United States; United States Food and Drug Administration; Zoledronic Acid

Metabolic disturbances of Na, K, Ca and glucose as paraneoplastic syndrome were reviewed on the basis of recent progress of such areas. These abnormalities usually occur due to the production of hormones or other physiologically active substances by tumor tissues. Hyponatremia is the most common abnormality of Na metabolism in patients with cancers such as lung cancer, malignant lymphoma, thymoma and so on. Usual cause of hyponatremia as paraneoplastic syndrome is inadequate secretion of Antidiuretic Hormone (SIADH), which brings dilution hyponatremia associated with water intoxication. Recently hyponatremia due to abnormal secretion of atrial natriuretic peptide has been noted. Ca metabolism disturbance associated with cancer is usually observed as hypercalcemia and it is said that such hypercalcemia is seen in about 10% of cancer patients. Main cause of hypercalcemia associated with cancer is local osteolytic hypercalcemia (LOH) due to bone metastasis or humoral hypercalcemia of malignancy (HHM). The most common etiology of HHM is the production of Parathormone (PTH) related peptide (PTH-rP) massively secreted from cancer tissues. PTH-rP has been recently well investigated and its molecular, mRNA and gene structure have been already determined. The progress of this area is very rapid and PTH-rP will be assayed in the clinical laboratory in near future. As for glucose metabolism disturbance as paraneoplastic syndrome, hypoglycemia is the most common abnormality. This type of hypoglycemia has been noted in relation with excessive production of somatomedin.

Topics: Atrial Natriuretic Factor; Calcium; Glucose; Humans; Hypercalcemia; Hyponatremia; Inappropriate ADH Syndrome; Paraneoplastic Syndromes; Potassium; Sodium

In studies in conscious dogs, 1 liter 0.3% calcium chloride infusion resulted in a 163% increase in serum ionized calcium (iCa2+), 166% increase in plasma immunoreactive atrial natriuretic peptide (irANP) and 33% increase in mean blood pressure with significant positive correlation between serum iCa2+ and plasma irANP levels. Pretreatment with verapamil reversed the effects of calcium infusion. These studies have demonstrated that calcium ions play an important role in ANP secretion with reversal by calcium antagonist, verapamil. Hyponatremia seen with calcium infusion could reflect calcium-enhanced sodium excretion. Hypercalcemia was accompanied by non-significant changes in plasma renin activity and significantly elevated serum aldosterone not reversed by verapamil.

Topics: Acute Disease; Aldosterone; Animals; Atrial Natriuretic Factor; Blood Pressure; Calcium Chloride; Dogs; Female; Heart Rate; Hypercalcemia; Verapamil

For the purpose of examining the role of calcium ion in the secretory process of atrial natriuretic polypeptide (ANP), we studied the effects of hypercalcemia and ouabain on plasma concentration of immunoreactive ANP (irANP). Pentobarbital sodium-anesthetized dogs were treated with calcium chloride infusion (0.136 mmol.kg-1.min-1, 10 min) or ouabain injection (30 micrograms/kg), and plasma irANP concentration, right atrial pressure, mean arterial pressure, heart rate, and serum calcium concentration were measured. To evaluate the effect of rising arterial pressure, plasma irANP concentration was also measured in dogs treated with phenylephrine hydrochloride (10 micrograms/kg). With calcium chloride infusion, serum calcium concentration and plasma irANP concentration, respectively, increased to about three times and about four times their basal levels. This increase of plasma irANP concentration was not attenuated by pretreatment with adrenoceptor blockers. Ouabain increased plasma irANP concentration to approximately 2.5 times the initial level. Neither calcium chloride nor ouabain produced any effect on right atrial pressure and heart rate, but both significantly increased mean atrial pressure. Phenylephrine caused a greater increase in mean arterial pressure than both calcium chloride and ouabain. However, there was no significant increase in plasma irANP concentration. These results suggest that the calcium ion may play a key role in the secretory process of ANP.

Topics: Anesthesia, General; Animals; Atrial Natriuretic Factor; Calcium Chloride; Dogs; Female; Hypercalcemia; Kinetics; Male; Ouabain; Radioimmunoassay; Reference Values