The combination of injection of tin-protoporphyrin IX and photoirradia
tion produced an acute decrease in serum glucose levels in rats, as we
ll as increased serum lactate dehydrogenase activity, and increased se
rum levels of creatinine and potassium. A reduction in the serum level
s of glucose was particularly noticeable. The severe hypoglycemia may
be one of the main causes of death in such rats.