Changes in the concentration of somatostatin and substance P in the cerebrospinal fluid following injection of alcohol into the pituitary gland.

The concentration of immunoreactive somatostatin and Substance P in the cisternal cerebrospinal fluid (CSF) of patients with pain due to malignant disease has been measured before and after injection of alcohol into the pituitary fossa. Following the first injection, a rise of 108 +/- 66% in CSF somatostatin levels was observed in 7 out of 13 patients, and a rise of 87 +/- 26% in 4 out of the 5 patients undergoing a second injection. A rise of 179 +/- 99% in levels of Substance P in CSF was observed in 4 out of 8 patients after a single injection. No change in peptide concentration was detected in peripheral plasma. Changes in CSF levels did not correlate with the degree of pain relief obtained, but patients with the greatest increase in somatostatin subsequently developed diabetes insipidus. The data are consistent with our previous experience that injection of alcohol into the pituitary fossa can cause destruction to nervous tissue, in addition to the obvious destruction of pituitary gland tissue. They do not support the suggestion that hypothalamic damage is necessary in order to obtain pain relief.