Myocardial necrosis due to vitamin D3 overdose -- scanning electron microscopic observations.

Our studies were carried out on the hearts of virgin female Wistar rats treated with 100,000 i.u. of vitamin D3 (calciol) per os for 3 consecutive days.

The effect of fasting and refeeding on the ultrastructure of the hypothalamic paraventricular nucleus in young and old rats.

In order to explore the morphological basis of the altered feeding behaviour of old rats, an ultrastructural investigation of the magnocellular neurons of the hypothalamic paraventricular nucleus (PVN) was performed. Young and old male Wistar rats, 5 and 24 months old, respectively, and with each age group comprising 12 animals, were divided into 3 groups. The rats in Group I were used as controls (normally fed), the rats of Group II were fasted for 48 hours and in Group III the rats were fasted for 48 hours and then refed for 24 hours.