Effect of prostacyclin on oedema formation and the transfer constant of 51Cr-EDTA following a brain trauma in the rat.

Effect of prostacyclin on oedema formation and the transfer constant of 51Cr-EDTA following a brain trauma in the rat.

Field: Disorders of the nervous system

Authors: Bentzer, P
Grände, P-O

Address of presenting
author: Department of Physiology, University of Lund, Sölvegatan 19, SE-223 62

E-mail: peter.bentzer@mphy.lu.se

Phone: +46 46 2227754

Fax: +46 46 2224546

Text of abstract: Background: Prostacyclin is a vasodilator with permeability reducing and antiaggregative properties. Infusion of prostacyclin is suggested to improve microcirculation in the penumbra zone following brain trauma in humans, and was recently shown to reduce cortical lesion volume following an experimental brain trauma in the rat. The aim of the present study was to investigate effects of a continuous prostacyclin infusion on microcirculation and oedema formation in the injured cortex following a brain trauma in the rat.
Methods: A brain trauma was induced using a fluid percussion trauma device and the animals were randomised to receive either 1or 2 ng/kg/min of prostacyclin or vehicle for 48 hrs. Oedema formation in the injured, in the adjacent and in the contra lateral cortex was measured using a wet vs. dry weight method. Cerebral uptake of intravenously administered 51Cr-EDTA was used to calculate a transfer coefficient (Ki) for the respective cortical area.
Preliminary results: There was an increase in brain oedema in the injured cortex for the prostacyclin animals at the dose of 2 ng/kg/min, as compared to the vehicle treated animals, whereas no increase in oedema was observed at a dose of 1ng/kg/min. Prostacyclin increased Ki for 51Cr-EDTA in a dose dependent manner.
Conclusion: The increased Ki for 51Cr- EDTA by prostacyclin may be explained by an increased vascular permeability but more likely by an increased vascular surface area available for diffusional exchange as prostacyclin is known to reduce permeability in other organs. The observed increase in oedema following infusion of prostacyclin may be a consequence of the above mentioned alterations but can also be a consequence of an increase in capillary pressure due to vasodilatation.

Keywords: Prostacyclin, brain trauma, oedima, permeability

	Effect of prostacyclin on oedema formation and the transfer constant of 51Cr-EDTA following a brain trauma in the rat.
Field:	Disorders of the nervous system
Authors:	Bentzer, P Grände, P-O
Address of presenting author:	Department of Physiology, University of Lund, Sölvegatan 19, SE-223 62
E-mail:	peter.bentzer@mphy.lu.se
Phone:	+46 46 2227754
Fax:	+46 46 2224546
Text of abstract:	Background: Prostacyclin is a vasodilator with permeability reducing and antiaggregative properties. Infusion of prostacyclin is suggested to improve microcirculation in the penumbra zone following brain trauma in humans, and was recently shown to reduce cortical lesion volume following an experimental brain trauma in the rat. The aim of the present study was to investigate effects of a continuous prostacyclin infusion on microcirculation and oedema formation in the injured cortex following a brain trauma in the rat. Methods: A brain trauma was induced using a fluid percussion trauma device and the animals were randomised to receive either 1or 2 ng/kg/min of prostacyclin or vehicle for 48 hrs. Oedema formation in the injured, in the adjacent and in the contra lateral cortex was measured using a wet vs. dry weight method. Cerebral uptake of intravenously administered 51Cr-EDTA was used to calculate a transfer coefficient (Ki) for the respective cortical area. Preliminary results: There was an increase in brain oedema in the injured cortex for the prostacyclin animals at the dose of 2 ng/kg/min, as compared to the vehicle treated animals, whereas no increase in oedema was observed at a dose of 1ng/kg/min. Prostacyclin increased Ki for 51Cr-EDTA in a dose dependent manner. Conclusion: The increased Ki for 51Cr- EDTA by prostacyclin may be explained by an increased vascular permeability but more likely by an increased vascular surface area available for diffusional exchange as prostacyclin is known to reduce permeability in other organs. The observed increase in oedema following infusion of prostacyclin may be a consequence of the above mentioned alterations but can also be a consequence of an increase in capillary pressure due to vasodilatation.

Keywords:	Prostacyclin, brain trauma, oedima, permeability

Index

Created 2000-03-29

Department of Physiological Sciences, Lund University

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