Ultrastructural study of liver cell damage induced by Ricin

Experiments were carried out on female albino (Wistar) rats to establish ri cin's liver damaging effect. In accordance with the data in the literature it seems that: 1. 2 mug/kg i.p. ricin (investigated 24 h later of its administration) has a detectable hepatotoxic effect; i.e. electron-density changes of cells and swelling of mitochondria. These findings correspond to the common and firs t ultrastructural signs of liver cell damage. This result was further stren gthened by the fact that serum ALT and AST values were significantly elevat ed compared to the control value. 2. The next steps of ricin's damaging effect have been detected at 10 mug/k g i.p. dose, - namely: Effect on smooth endoplasmic reticulum: in its place there is a loose, foam-structured unidentified material, - while in the gr anulated endoplasmic reticulum the number of ribosomes decreased, similarly to the glycogen granules 3. 200 mug/kg i.p. ricin caused a severe liver-cell damage. The mitochondri a showed early degenerative signs, - and both endoplasmic reticulums were f urther damaged. The most significant feature is the complete lack of riboso mes in the tubular structure of the granulated endoplasmic reticulum. This latter finding enlights the known inhibitory effect of ricin on protein syn thesis. The serum enzyme-levels remained in the pathological range. No earl y sign of enzyme (Cytochrome P-450) induction could be observed. According to the literature RIC is one of the five most toxic materials kno wn: Tetanus toxin, botulinus toxin, diphteria toxin, gramicidin, RIC (HAUSC HILD 1956). FUHRMAN (1967) considers that RIC is the most toxic substance o f plant origin. It is known that RIG, - among others, - has a liver damaging effect too (FU NATSU 1964; KOGA et al. 1965; BALINT and HALASZ 1972). In this paper we would like to report our further experimental results rega rding RIC's hepatotoxic effect in rats.