INVITRO CELLULAR EFFECTS OF HEMATOPORPHYRIN DERIVATIVE

Abstract

Several in vitro cell systems were exposed to hematoporphyrin derivative (HPD): established lines of rat kangaroo epithelial kidney PTK2 cells; normal mouse embryonic fibroblasts; and differentiated neonatal rat myocardial cells. The uptake of HPD (25-100 .mu.g/ml) by individual cells occurred rapidly over a 2-h period and leveled off by 24 h. HPD was excreted from cells by 48 h after exposure. A low level of HPD (above background) was maintained in cells for up to 4 days following cessation of exposure. Intracellular binding of HPD was to mitochondria as demonstrated by fluorescence microscopy. HPD also had a growth-inhibiting effect on rat Kangaroo cells without added light. The growth effects on mouse cells were less marked. The use of HPD plus light for therapeutic management of cancer is discussed.