In mammals, nitric oxide (NO) plays important roles in many physiological function such as endothelium-dependent vascular relaxation, non-adrenergic non-cholinergic neurotransmission. Some cytotoxic actions of activated macrophages are also
mediated by
NO. Growth-inhibitory effects of macrophage-derived NO have been known in tumor cells, intracellular tropozoites, fungi, intracellular mycobacterium, and lymphocytes. In the present study anti-bacterial effects of NO were investigated.
S-Nitroso-N-acetly-d, L-penicillamine (SNAP) was used to produce NO in solution. SNAP at the concnetration of 5 mM inhibited the growth of Staphylococcus aureus, Bacillus anthracis and Escherichia coli in nutrient broths by 80, 95 and 60%
respectively.
in 3 h incubation at 37℃. The growth of Salmonella paratyphi B was completely inhibited by the same concetration of SNAP. SANP is decomposed to NO and N-acetyl-D, L-penicillamine during the incubation in an aqueous solution. NO rapidly reacts
with
itself, oxygen and water to generate accumulating endproducts, nitrite and nitrate. Neither sodium nitrite nor N-acetyl-d, L-penicillamine at the concentration of 5 mM was growth-inhibitory. These results indicate that NO produced from SNAP
inhibits
bacterial growth. The grwoth inhibitory effects of SNAP was partially reduced by addition of deoxyribonucleosides, which can be converted to deoxyribonucleotide in the absence of ribonucleotide reductase. Therefore, the inhibitory effects of NO
on
bacterial growth may due to the deactivation of ribonucleotide reductase.
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