Effects of light exposure on the uptake of photofrin II in tumors and normal tissues

Abstract

DBA mice bearing CaD2 mammary carcinomas were used to determine the effect of giving small doses of light to the tumor area 1.5 hr after injecting Photofrin II (PII). The smallest light dose applied (12.5 J/cm2) had no effect on the uptake of PII in the tumor and its surrounding tissues, as measured 24 hr after the i.p. injection. However, several higher light doses increased the uptake of PII in the tumor significantly, the uptake in skin slightly, while the uptake in muscle tissue was decreased rather than increased. Thus, the PII concentration ratio between the tumor and the surrounding normal tissues was significantly improved. The rates of clearance of PII from irradiated tissues and non-irradiated tissues were not significantly different. Most likely, the present observations are due to transient pH lowering in the tumor resulting from vascular damage.

Production of protoporphyrin IX induced by 5-aminolevulinic acid in transplanted human colon adenocarcinoma of nude mice can be increased by ultrasound

“…Amounts of PpIX in tissues were determined as previously described (Ma et al, 1992). Briefly, immediately after collection, fresh tissue samples were rinsed twice in PBS, blotted dry on clean paper, weighed and then brought into suspension in a solution of 1% SDS in 1 N perchloric acid/methanol (1:1 v/v) by means of an Ystral (Dottingen, Germany) mechanical homogenizer.…”