The influence of transient spinal ischemia on substance P positive nerve structures.

The aim of this study was to investigate, if transient spinal ischemia and a period of 4-day reperfusion will change the distribution pattern of substance P in the spinal cord of rabbits. Strongly enhanced staining of substance P positive nerve structures appeared in the superficial dorsal horn (laminae I, II), the Lissauer's tract, the pericentral region (lamina X), and in the areas of autonomic nuclei (sympathetic-intermediolateral--IML nucleus and parasympathetic-sacral parasympathetic nucleus--SPN) in the control group. Transient spinal ischemia was produced by occlusion of the abdominal aorta just below the left renal artery. Neuropathology of the lesion 4 days after transient ischemia was characterized by selective necrosis of gray matter in the central part of dorsal horn and medial portions of anterior gray matter. Areas with the most dense accumulation of substance P positive structures stayed almost intact. Therefore, no significant change in the distribution pattern of substance P was found in the spinal cord of animals with ischemia-reperfusion-induced injury.