Immunomodulatory effect of laser on whole body exposure.

All biomedical laser applications are based on the interaction of laser light with biological system. During the past decade considerable evidence has accumulated demonstrating that non-thermal exposure to laser can elicit cellular changes in the immune system. In the present study, we have analyzed the effect of laser on immune response in rats. A group of rats were exposed to 0.225 mu j/cm2 for 90 min for 3 days in specially designed fiberglass chambers. The whole body exposure of rats of He-Ne laser modulated both the humoral and cellular responses to tetanus toxoid stimulation. Plain red light used as a control for red laser light showed an appreciable degree of response as compared to the control groups, but not to the extent of the response to laser. Non-responders turned responders after exposure to laser. There was no response in unimmunized groups when exposed to laser and red light alone. The early and heightened immune response and proliferation of lymphocytes after exposure to laser is suggestive of a complex interaction at the cellular immune response level.

Induction of stress proteins in response to hypoxia.

Hypoxia is a severe stress factor to which man and most other mammalian species are capable of adapting. However, the cellular mechanism which enable cells to adapt are still unknown. Effect of hypoxia was studied on the synthesis of hypoxia induced proteins in rat kidney and in vero cell line (monkey kidney). These were exposed to hypoxia at 240 mmHg pressure for 1 hr. The induction of stress protein was determined by probing with monoclonal antibodies against 65 kDa heat shock protein (hsp65). The induction of a 65 kDa protein was 3.6 fold higher to the total cellular protein, both in cell lines and kidney of rats. In vivo response was predominantly observed in renal cortical region particularly in glomeruli. The induction of stress proteins during hypoxia suggests their importance in the maintenance of cellular integrity under hypoxia.