Regional distribution of somatostatin-like immunoreactivity in the human brain

The regional distribution and chromatographic characteristics of somatostatin-like immunoreactivity (SLI) were studied in autopsy specimens of 8 human brains. SLI concentrations in 8 different regions of these brains ranged from (mean +/- S.E.) 756.3 +/- 363.4 pmol/g tissue in anterior hypothalamus to 1.6 +/- pmol/g in cerebellum. Chromatography of the extracts of human brain cortex, anterior hypothalamus, thalamus and amygdala on Sephadex G-50 disclosed one major peak which corresponded to the elution peak of synthetic somatostatin. Since the human brains were obtained at autopsy 11-36 h after death, the effects of temperature and time lapse between death and tissue extraction on SLI concentration and chromatographic pattern in rat brain were examined. After storage at 4 degrees C or 23 degrees C for 2 h and 8 h, a significant increase in SLI concentration was noted, although by 24 h in increase was no longer observed. A gradual loss in the eluting forms of SLI on gel chromatography was observed with storage at 4 degrees C or 23 degrees C.