Cerebrospinal fluid (CSF) and plasma levels of
somatostatin have been measured in patients with active
acromegaly and the results compared to those obtained in patients with non-
endocrine diseases. Plasma levels have also been studied in acromegalics given oral
glucose. The mean CSF
somatostatin level in twenty patients without
endocrine disease was 76 pg/ml (range 46-112) which did not differ significantly from that found in eight acromegalics (mean 87 pg/ml, range 48-160). Plasma
somatostatin in twenty-two acromegalic patients on no medical treatment was 43 pg/ml (range 9-113), not significantly different from values in a normal control population. There were no differences in the
somatostatin levels of non-diabetic acromegalics. After oral
glucose, there was a rise in circulating
somatostatin in eleven out of twelve acromegalic patients, and this rise did not differ from that seen in normal subjects. It is probable that altered
somatostatin secretion is neither the cause nor the result of
acromegaly; however it is possible that local changes in
somatostatin concentration which are not reflected in peripheral plasma or CSF levels may occur near the site of its production.