Presence of growth hormone-releasing factor-like immunoreactivity in rat duodenum.
Growth hormone-releasing factor-like immunoreactivity (GRF-LI) was detected in partially purified extracts of rat hypothalamus and duodenum with a highly specific RIA for rat GRF (rGRF). The concentration of rGRF-LI in the rat hypothalamus was 32.5 fmol/mg dry weight (455 fmol or 3.18 ng/region), while the rat duodenum contained 2.15 fmol/mg dry weight (111 fmol or 0.78 ng/region). Partially purified hypothalamic and duodenal extracts exhibited displacement of the tracer parallel to rGRF. GRF-LI levels in all other brain regions (brainstem, cortex) or gastrointestinal tract tissues (forestomach, antrum, ileum, colon, pancreas) measured were close to the detection level of the RIA. rGRF-LI in hypothalamic and duodenal extracts behaved like synthetic rGRF in both gel filtration and reverse-phase HPLC systems. Coelution of rGRF-LI contained in both these tissue extracts with synthetic rGRF suggests that these molecules are similar, if not identical.
D000818:Animals; D001933:Brain Stem / Q000032:analysis; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004386:Duodenum / Q000032:analysis*; D013007:Growth Hormone-Releasing Hormone / Q000032:analysis*; D007031:Hypothalamus / Q000032:analysis; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D014018:Tissue Distribution
D013007:Growth Hormone-Releasing Hormone