Dexamethasone reduces fat-induced release of neurotensin in the rat.

The effect of glucocorticoids on the release of neurotensin (NT) was studied in the rat. Oleic acid (200 microliters) was instilled into the duodenum of fasted rats given saline or 1 mg . kg-1 dexamethasone subcutaneously 16 h prior to the experiment. Neurotensin-like immunoreactivity (p-NTLI) was analysed in unextracted plasma with the C-terminal directed NT antiserum 6-8206. Pretreatment with dexamethasone almost totally abolished the fat-induced increase in p-NTLI. The data suggest that glucocorticoids may modulate the post-prandial release of NT. Since NT is known to constrict the vascular beds of subcutaneous adipose tissue, this effect of glucocorticoids may be one of the factors responsible for the abnormal distribution of fat caused by high levels of glucocorticoids, e.g. in Cushing's syndrome.