Chronic hypervitaminosis D3 determines a decrease in C-cell numbers and calcitonin levels in rats.

Many papers have reported that chronic hypercalcemia induced either by large doses of vitamin D or by the administration of calcium or parathormone, produces hypertrophy and hyperplasia of C cells. However, more recent studies suggest that the effect of elevated calcium or 1.25(OH)2D3 concentration on the production of calcitonin may be more complex than previously suspected. To assess the validity of such a response an experimental model, where hypercalcemia was induced with vitamin D3 overdose, was designed. Male Wistar rats were administered vitamin D3 chronically (50,000 IU per 100 ml of drinking water with or without CaCl2). Serum calcium and calcitonin levels were determined. C cells were stained by immunohistochemistry using calcitonin and neuronal specific enolase (NSE) antibodies and their percentage was calculated by a morphometric analysis. We also investigated the ultrastructural characteristic of the C cells under experimental conditions. C cells did not have a proliferative response rather a decrease in their number was observed after 1 month of treatment with 25,000 IU of vitamin D3 (1.55 vs 2.43% in control animals) and 3 months with vitamin plus CaCl2 (2.27% vs 3.62% in control animals). In addition, no significant changes in serum calcitonin levels were observed during the experimental period. We conclude that rat C cells do not respond with hypertrophic and hyperplastic changes in a hypercalcemic state due to an intoxication with vitamin D3.

Characteristics of a population undergoing treatment for drug addiction in a therapeutic community setting in Spain.

The authors discuss the findings of a study of the personal history characteristics of a population of 223 individuals who underwent treatment for drug addiction at the Masma Therapeutic Community, Lugo, Spain, during the period September 1984 to March 1986. The population consisted of 58 females and 165 males, predominantly from middle-class backgrounds. Nearly all were multiple drug abusers, cannabis and heroin being the most widely abused drugs. Over half the population received treatment prior to admission to the Masma Community for the abuse of either barbiturates or opiates. The research instrument used was a self-report questionnaire, completed by participants anonymously and on a voluntary basis. It included items relating to personal and family background, aspects of drug abuse and type of prior treatment.