Abstract: AIM: To study the changes of NO concentrations of different tissues in stress rats.METHODS: Add stimulation with experiments employed electric food-shock and noise of busser as stressor for 15 days in SD rats, NO concentrations and BP were measured.RESULTS: In stress group, BPs increased before and after stress stimulation, but decreased levels NO concentrations of plasma, and there was no detectable amounts of NO in auricle, ventricle, vessel and adrenal.In stress +L-arg group, BPs did not increase before and after stress stimulation, NO concentrations of plasma increased, but auricle, ventricle, vessel and adrenal maintained the concentrations of NO.CONCLUSION: The stress stimulation can increase BP and low NO concentration, and L-arg can resist the response.

Key words: stress, BP, NO concentration, L-arg, rats