Calcium kinetics in the Solanum malacoxylon-treated rat.

The chronic ingestion of the leaves of the plant Solanum malacoxylon (SM) causes an endemic disease in the cattle of some areas of Buenos Aires province. The animals affected manifest loss of appetite and weight, hypercalcemia, hyperphosphatemia, and ectopic calcifications. In order to study the mechanism of the hypercalcemia provoked by the administration of SM, a calcium kinetic study was performed in control and treated adult intact rats. The animals receiving SM showed higher levels of serum calcium throughout the study. The body excretion of 47Ca and the size of the most rapidly exchangeable calcium pool were also elevated. On the other hand, the bone accretion rate and the urinary excretion of total hydroxyproline were significantly diminished. The results indicate that during the early phase of SM administration in intact rats, bone turnover rate is depressed.