Effects of photofrin II and light on cellular adenine nucleotides and their modulation.

Effects of photofrin II (PII) and light on the intra cellular nucleotide levels have been investigated using BHK-21 cell line. Results indicate that lower concentrations of photofrin II in dark increases ATP levels in a non linear manner, however, there has been no change in energy charge and levels of other nucleotides. Photoirradiation of PII-treated cells leads to a significant reduction in ATP levels and energy charge along with an increase in ATP breakdown products like ADP and AMP. The phosphorylation potential [ATP]/[ADP][Pi] also reduces upon photoirradiation of PII treated cells. Incubation conditions like pH of the medium and temperature modulate the cellular responses to a great extent.