EN
Nitric oxide plays a critical role in a variety of biological acfivities. It has been nicknamed a ,,killer'' and ,,mediator" due to its toxic and signalling properties. Apart from its regular physiological function, nitric oxide indirectly participates in infectious diseases. Our report seems to be first presentation of the nitric oxide synthase participation in the host biochemical defence mechanisms and in morphological transformation of muscle cells in trichinellosis.