6-Sulfidopeptide-containing leukotriene-like immunoreactivity was synthesized in gerbil forebrains after bilateral common carotid occlusion and reperfusion. At 5, 10, or 15 minutes of ischemia, concentrations increased significantly and became more marked on reperfusion. Immunoreactivity was highest in forebrain gray matter and was below the detection limit of the assay in brain regions remote from the zone of ischemia. In vitro experiments with vascular cells and organ cultures of cerebral arteries indicate that the cerebral blood vessel wall is not a major source of biosynthetic activity in the brain. These experiments demonstrate leukotriene biosynthesis by the brain. Because synthesis occurs during ischemia and reperfusion and because leukotrienes are potent vasoconstrictors and promoters of tissue edema, they may play a role in the pathophysiology of cerebral ischemia.

The use of non-neural conduits to bridge gaps in peripheral nerves has been noted in the literature for many years. A logical extension of this concept is the introduction of neurotrophic or growth promoting factors into the lumen. We present here an injectable nerve guide that allows percutaneous access to the microenvironment of the regenerating peripheral nerve within the guide's lumen. Hyaluronic acid, a compound associated with decreased scarring and improved fibrin matrix formation, is added sequentially to the regenerating peripheral rat sciatic nerve via this injectable nerve guide. Assessment of nerve regeneration and reinnervation shows better conduction velocity, higher axon counts, and a trend toward earlier myelination with hyaluronic acid compared with saline. This work not only implies hyaluronic acid's role as an agent that aids nerve growth but also describes a new tool that allows percutaneous access to the milieu of a regenerating nerve.

The use of non-neural conduits to span gaps in regenerating peripheral nerves has been noted in the literature for many years. An intriguing addition to this so-called entubulation repair method is the continuous instillation of neuronotrophic or growth factors into the lumen of the guide to bathe the regenerating nerve. A model is presented which uses an osmotic pump that supplies a constant, reproducible amount of solution into the lumen of a nerve guide without disrupting the regeneration process.