Diagnostic value of plasma C-type natriuretic peptide levels in determination of the duration of mesenteric ischaemia

OBJECTIVE: Mesenteric arteries release C-type natriuretic peptide (CNP), which hyperpolarises vascular smooth muscle. We measured the levels of this peptide after inducing mesenteric ischaemia over a series of time intervals, so as to determine its predictive value in demonstrating the severity of ischaemia in a rat model. METHODS: A total of 32 rats were allocated to four groups containing eight rats each. Basal CNP reference levels were measured in the control group, which was not exposed to any intervention. In groups I, II and III, mesenteric ischaemia was induced over three, six and nine hours, respectively, and plasma CNP levels were measured afterwards. Mesenteric ischaemia was induced by clamping the superior mesenteric artery. RESULTS: In comparison with the controls (2.38 ± 0.18 pg/ml), CNP levels were relatively lower in group I (2.54 ± 0.42 pg/ml). However, significant increases in plasma CNP levels were observed over longer periods of ischaemia in group II, at 5.23 ± 0.22 pg/ml, and in group III, at 6.19 ± 0.67 pg/ml (p < 0.05). A significant direct relationship was determined between plasma CNP levels and prolonged intervals of mesenteric ischaemia (R = 0.56, p < 0.001). CONCLUSION: Measuring plasma CNP levels in patients with acute mesenteric ischaemia may be beneficial in estimating the time period over which the ischaemic injury has occurred.