Changes in the C-type Natriuretic peptide (CNP) and NO derivatives in the plasma and CSF of the patients with subarachnoid hemorrhage (SAH)

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The aim of this study was to determine a role of CNP and NO for cerebral vasospasm following subarachnoid hemorrhage (SAH). Both of them are endothelium-derived relaxing factor (EDRF), and CNP exists in the brain as a cerebral vasodilator. We conducted a one week monitoring of CNP and NOx levels in the plasma and cerebrospinal fluid (CSF) in 26 patients who received clipping operation within 24 h after the occurrences of SAH, and classified to the Group A (angiographical spasm +), and Group B (angiographical spasm -). And we examined CNP and NO, levels in the CSF of the patients who received spinal anesthesia for a small operation as a reference patients.

Results

CNP levels in the CSF on day 1 of hospitalization was higher than that of the reference patients and the level decreased significantly on day 7, but we did not observe any significant difference between the groups. CNP levels in the plasma did not change.

NOx levels in the CSF in the week following SAH were higher than the levels of the reference patients, and the level in Group A was higher than in Group B on day 1. Only in Group A did NOx levels decrease significantly from day 3. NOx levels in the plasma did not change significantly.

Conclusions

CNP levels in the CSF were high in the acute phase following SAH, while plasma CNP levels were maintained at a constant. But any specific role of CNP for cerebral vasospasm was not indicated from our findings.

We considered that NOx in the CSF has a role as an inhibitor for cerebral vasospasm following SAH, because NOx levels decreased significantly only in the vasospasm group, while plasma NOx levels did not change significantly.