Am. J. Respir. Crit. Care Med., Vol 150, No. 4, Oct 1994, 924-928.
Neurogenic inflammation and lowering of interstitial fluid pressure in rat trachea is inhibited by alpha-trinositol
K Woie and RK Reed
Department of Physiology, University of Bergen, Norway.
The effect of alpha-trinositol (D-myoinositol-1,2,6-triphosphate) on edema
formation and capillary permeability in neurogenically induced inflammatory
edema was investigated in rat trachea. Interstitial fluid pressure (Pif)
was studied, since increased negativity of Pif contributes to edema
formation in this situation. alpha-Trinositol was used because it inhibits
edema formation, capillary leakage, and increased negativity of Pif in
burn-injured skin. Pif was measured with sharpened glass capillaries (3 to
7 microns) connected to a servocontrolled counterpressure system after
circulatory arrest (induced by intracardiac injection of saturated
potassium chloride in pentobarbital anesthesia). This was done in order to
avoid the edema formation associated with inflammatory reactions, which
will raise interstitial fluid volume and Pif, causing the underestimation
of an increased negativity of Pif. Neurogenic inflammation induced by
electrical-field stimulation of the left vagal nerve (10 V, 20 Hz, 0.5 ms)
lowered Pif from -1.4 +/- 0.6 mm Hg to -8.4 +/- 2.1 mm Hg (p < 0.01).
Corresponding numbers after the intravenous administration of
alpha-trinositol (40 mg/kg) before stimulation were -1.2 +/- 0.4 and - 1.4
+/- 0.4 mm Hg, respectively (p > 0.05). Another series of animals with
intact circulation was used to study the effect of vagal nerve stimulation
and alpha-trinositol on edema formation (total tissue water and
extravascular 51Cr-ethylenediamine tetraacetic acid-[EDTA] space) and
albumin extravasation. These parameters increased significantly after vagal
nerve stimulation, while intravenous alpha-trinositol (40 and 120 mg/kg),
as given above, significantly attenuated this increase. Thus,
alpha-trinositol prevented a lowering of Pif and the edema formation
accompanying neurogenic inflammation in rat trachea.
