The effect of vagotomy on hepatic regeneration in rats.

Liver regeneration was studied in rats that had undergone a bilateral cervical vagotomy. DNA synthesis, measured as the incorporation of 3H-thymidine into DNA, AT 24 hr after partial hepatectomy was significantly reduced in vagotomized rats. Ornithine decarboxylase (ODC) activity was significantly less at 4 hr after partial hepatectomy in vagotomized rats but was equal to controls at 8 and 24 hr. This data suggest that the liver parenchyma receives vagal innervation and that this innervation may play a role in the control of liver regeneration.

Cerebrovasculature permeability changes following experimental cerebral angiography. A light- and electron-microscopic study.

Morphological alterations of the cerebral vasculature as related to the permeability of plasma proteins and angiographic contrast media following unilateral cerebral angiography were studied. Both Evans blue albumin and horseradish peroxidase were employed as protein tracers for light and electron microscopy investigation respectively. Grey matter regions of the cerebral cortex, cerebellum corpus striatum, hippocampus and midbrain showed the most extensive and consistent leakage of these protein tracers. The most extensive penetration of EBA was noted at 1 hr following cerebral angiography as compared to the 5 or 30 min sample times. Permeability changes were noted in small venules and arterioles as well as capillaries. The extent of permeability, however, was appreciably greater in the capillaires as evidences by rapid extravasation of HRP into the surrounding neuropil extracellular spaces. The glial basement membrane surrounding the perivascular spaces of small venules and arterioles precluded rapid penetration of HRP into the neuropil interstitium. Opening of the tight junctions between the endothelial cells was primarily responsible for the extravasation of HRP in all vessel types. Furthermore, it is out opinion that the hyperosmolar nature of the contrast medium is responsible for opening of these tight junctions.

Cardiovascular effects of cerebroventricular ouabain perfusion in the adult dog.

Cerebroventricular perfusion with artificial cerebrospinal fluid containing 10(-5) M ouabain was performed in adult dogs in order to describe the time course of the cardiovascular effect of intraventricular ouabain and to evaluate treatments to eliminate the cardiovascular effect. The central effect of ouabain caused a 56% increase in blood pressure above control values and a 35% increase in heart rate with various cardiac arrhythmias. Both alpha- and beta-adrenergic blocking drugs given intravenously.altered the pressure and rate effects ou ouabain, whereas vagotomy attenuated the effect.