Endothelial microvilli in the vessels of the rat gasserian ganglion and testis

Summary In the Gasserian ganglion and testis of the rat the endothelium of the small blood vessels has a singular appearance due to the presence of a high number of microvillous processes. These arise from the luminal surface, either individually, or in small groups. The significance of this structure is not known. It is pointed out that these vessels are particularly sensitive to cadmium intoxication.This investigation was performed during a tenure by Dr. Gabbiani of a fellowship of the Medical Research Council of Canada and was supported by the National Institutes of Health (Grant No. 5R01 HE-08794-04) and the Ministère de la Santé du Québec (projet 604-7-635).The authors wish to thank Dr. S. M. Shea for his advice in the measurement of the villi. The technical assistance of Miss Virginia Gilmore and of Mr. Eduardo Garriga is gratefully acknowledged.