Presence of biologically and immunologically active secretin-like substance in the mammalian brain.
The present study involves the isolation and characterization of secretin-like immunoreactivity from the brains of pigs, rats and dogs. Secretin-like immunoreactivity was extracted with 0.1 N HCl and subjected to SP-Sephadex ion exchange chromatography and gel filtration on a Sephadex G-50 superfine column. The average amounts of secretin-like immunoreactivity in the extracts of 2 pigs, 7 rats and 6 dog brains were 0.25 ng/g, 2.4 +/- 0.2 ng/g and 0.34 +/- 0.07 ng/g fresh tissue weight, respectively. The secretin-like immunoreactivities in the brain extracts exhibited the same retention coefficient as natural porcine secretin on gel filtration and were eluted in the same salt gradient from the SP-Sephadex column. A partially purified secretin-like immunoreactivity isolated from canine brain exhibited the same bioactivity as natural porcine secretin to stimulate pancreatic volume flow in anesthetized rats (n = 4). These results indicated that secretin-like immunoreactivities from brain extracts possess the same molecular size and charge as natural porcine secretin and the secretin-like immunoreactivity isolated from dog brain is active in stimulating pancreatic secretion in anesthetized rats.
D000818:Animals; D001681:Biological Assay; D001923:Brain Chemistry; D002850:Chromatography, Gel; D004285:Dogs; D007118:Immunoassay; D010189:Pancreatic Juice / Q000187:drug effects / Q000378:metabolism; D012633:Secretin / Q000302:isolation & purification* / Q000494:pharmacology; D013552:Swine
D012633:Secretin