Degradation and processing of cholecystokinin in guinea pig fundic gastric glands.
The degradation of 125I-CCK8 in guinea pig fundic gastric glands was time and temperature dependent. At both 24 and 37 degrees C, dithiothreitol (DTT) and chloroquine reduced the degradation of the internalized 125I-CCK8. After 60 min of binding, DTT, chloroquine and DTT plus chloroquine together significantly reduced radioligand degradation by 43, 55 and 66%, respectively, compared to control at 24 degrees C, and these differences remained significant after 1, 2 and 3 hr of processing. Similar effects were noted at 37 degrees C. About 75% of the radioactivity appearing in the supernatant after 60 min of exocytosis at 37 degrees C represented degraded material as measured by both Sep-Pak chromatography and rebinding methods. DTT and chloroquine both significantly reduced the amounts of degraded radioligand exocytosed from these glands.
Ramani
N
N
Department of Medicine, Nassau County Medical Center, East Meadow, NY 11554.
Praissman
M
M
D000818:Animals; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D002738:Chloroquine / Q000494:pharmacology; D002766:Cholecystokinin / Q000378:metabolism*; D002850:Chromatography, Gel; D004229:Dithiothreitol / Q000494:pharmacology; D004357:Drug Synergism; D005748:Gastric Fundus / Q000187:drug effects / Q000378:metabolism*; D005753:Gastric Mucosa / Q000187:drug effects / Q000378:metabolism*; D006168:Guinea Pigs; D008297:Male; D013696:Temperature; D013997:Time Factors
D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D002738:Chloroquine; D002766:Cholecystokinin; D004229:Dithiothreitol