Bovine and human pineal glands contain substantial quantities of endothelial cell stimulating angiogenic factor.

Using a quantitative assay the amount of a low Mr endothelial cell stimulating angiogenesis factor (ESAF) has been determined in human pineal glands and bovine brain, retina, pineal gland, liver and kidney. Pineal glands contain approximately ten times as much ESAF as the retina or grey and white matter from the cerebral cortex and a hundred times as much as highly vascular tissues such as liver and kidney. The relevance of these findings to the highly vascular nature of the pineal gland is discussed.