Bombesin-induced changes in expression of pancreatic enzymes in young and old rats.
Bombesin is known to induce pancreatic growth. In aged animals, reduced responsiveness of tissues of the gastrointestinal tract to a number of hormones/peptides, including bombesin, has been demonstrated, yet the effects of chronic bombesin administration on the aging pancreas is poorly understood. In the present study, groups of 4- and 20- to 22-month-old male Fischer 344 rats were infused by osmotic minipump with saline (control) or bombesin (300 ng/kg/h) for 14 days. In young rats, bombesin administration increased trypsin activity in the pancreas, which was accompanied by an increase in trypsinogen steady-state mRNA levels. However, this response to bombesin was not observed in aged rats. Bombesin also increased pancreatic glutathione peroxidase and reductase, but not superoxide dismutase activity in young rats, whereas activity of these antioxidant enzymes was not affected by bombesin in old rats. These data further support the observation that responsiveness of the pancreas to hormones is diminished with advancing age.
Dubick
M A
MA
Letterman Army Institute of Research, Division of Military Trauma Research, SGRD-ULY-MT, San Francisco, California 94129-6800.
Cornell
T
T
Majumdar
A P
AP
D000375:Aging / Q000378:metabolism*; D000681:Amylases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001839:Bombesin / Q000494:pharmacology*; D008297:Male; D010179:Pancreas / Q000201:enzymology*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D013482:Superoxide Dismutase / Q000378:metabolism; D014357:Trypsin / Q000235:genetics / Q000378:metabolism*; D014362:Trypsinogen / Q000235:genetics
D012333:RNA, Messenger; D014362:Trypsinogen; D013482:Superoxide Dismutase; D000681:Amylases; D014357:Trypsin; D001839:Bombesin