Plasma arginine-vasopressin following experimental stroke: effect of osmotherapy.

Abstract

Neurohumoral responses have been implicated in the pathogenesis of ischemia-evoked cerebral edema. In a well-characterized animal model of ischemic stroke, the present study was undertaken to 1) study the profile of plasma arginine-vasopressin (AVP), and 2) determine whether osmotherapy with mannitol and various concentrations of hypertonic saline (HS) solutions influence plasma AVP levels. Halothane-anesthetized adult male Wistar rats were subjected to 2 h of middle cerebral artery occlusion with the intraluminal filament technique. Plasma AVP levels (means +/- SD) were significantly elevated at 24 h (42 +/- 21 pg/ml), 48 h (50 +/- 28 pg/ml), and 72 h (110 +/- 47 pg/ml), and returned to baseline at 96 h (22 +/- 15 pg/ml) following middle cerebral artery occlusion compared with sham-operated controls (14 +/- 7 pg/ml). Plasma AVP levels at 72 h were significantly attenuated with 7.5% HS (37 +/- 8 pg/ml; 360 +/- 11 osmol/l) compared with 0.9% saline (73 +/- 6; 292 +/- 6 osmol/l), 3% HS (66 +/- 8 pg/ml; 303 +/- 12 osmol/l), or mannitol (74 +/- 9 pg/ml; 313 +/- 14 osmol/l) treatment. HS (7.5%) significantly attenuated water content in the ipsilateral and contralateral hemispheres compared with surgical shams, 0.9% saline, 3% HS, and mannitol treatments. Peak plasma AVP levels were not associated with direct histopathological injury to the anterior hypothalamus. Attenuation of brain water content with 7.5% HS treatment coincides with attenuated serum AVP levels, and we speculate that this may represent one additional mechanism by which osmotherapy attenuates edema associated with ischemic stroke.

• Authors: Yi Chang, Tsung-Ying Chen, Chih-Hung Chen, Barbara J Crain, Thomas J K Toung, Anish Bhardwaj
• Journal: Journal of applied physiology (Bethesda, Md. : 1985) (J Appl Physiol (1985)) Vol. 100 Issue 5 Pg. 1445-51 (May 2006) ISSN: 8750-7587 [Print] United States
• PMID: 16339345 (Publication Type: Comparative Study, Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Saline Solution, Hypertonic
• Arginine Vasopressin
• Mannitol

Topics

• Animals
• Arginine Vasopressin (blood)
• Brain Edema (blood, etiology, physiopathology, therapy)
• Dose-Response Relationship, Drug
• Infarction, Middle Cerebral Artery (complications)
• Ischemic Attack, Transient (blood, complications, physiopathology, therapy)
• Male
• Mannitol (therapeutic use)
• Rats
• Rats, Wistar
• Saline Solution, Hypertonic (therapeutic use)
• Stroke (blood, etiology, physiopathology, therapy)
• Stroke Volume (physiology)