Smooth muscle has been shown to be highly sensitive to the specific reactions occurring in anaphylactic shock. Schultz (1) demonstrated that all organs of the guinea pig containing smooth muscle contracted to a greater or lesser degree when the animal became anaphylactic. This was true of blood vessels as well as other organs with smooth muscle. From these findings one would be justified in expecting some degree of cerebral vascular spasm during anaphylactic shock. The experiments here reported were designed to observe this phenomena through the cranial window.
Method A cranial window and head holder for the small skull of the guinea pig were designed by Dr. Henry S. Forbes, otherwise the technic was similar to that usually employed in this laboratory (2). Because anaphylactic shock is inhibited under a general anesthetic, the trephine work for the window was done under a combined local and general anesthesia. The ether was discontinued after the preliminary preparations, and the operation finished under 2 per cent novocaine.