Effect of maternal zinc deficiency or food restriction on rat fetal pancreas. I. Procarboxypeptidase A and chymotrypsinogen.
Maternal zinc deficiency lowered the protein, zinc and zymogen content of the day 19 rat fetal pancreas. Pregnant Sprague-Dawley rats were fed a zinc-deficient diet (0.4 +/- 0.1 ppm zinc) and libitum or a zinc-supplemented control diet (100 ppm zinc) either ad libitum or with restricted intake. At day 19 of pregnancy, the pancreata from zinc-deficient fetuses contained 50% less zinc and 15% less cellular protein than did fetal pancreas from normal or restricted intake controls, although DNA content was normal. Zymogen granulation of pancreatic acinar cells from zinc-deficient fetuses was decreased. The two major proteolytic zymogens of the rat fetal pancreas--procarboxypeptidase A, a zinc metalloprotein, and chymotrypsinogen--were each 30% lower per cell in zinc-deficient fetuses than in controls. Zinc-deficient fetuses taken from large litters of seven or more young per litter had lower levels of procarboxypeptidase A and chymotrypsinogen in the pancreata than did fetuses taken from smaller litters. The results suggest that exocrine zymogen accumulation is lower than normal in the pancreata of zinc-deficient fetuses, irrespective of the zinc dependency of the enzyme proteins involved.
D000818:Animals; D002268:Carboxypeptidases / Q000378:metabolism*; D043422:Carboxypeptidases A; D002919:Chymotrypsinogen / Q000378:metabolism*; D004032:Diet; D002149:Energy Intake; D004792:Enzyme Precursors / Q000378:metabolism; D005260:Female; D005508:Food Deprivation / Q000502:physiology; D008431:Maternal-Fetal Exchange; D010179:Pancreas / Q000196:embryology* / Q000201:enzymology; D011247:Pregnancy; D051381:Rats; D015032:Zinc / Q000172:deficiency* / Q000378:metabolism
D004792:Enzyme Precursors; D002919:Chymotrypsinogen; D002268:Carboxypeptidases; D043422:Carboxypeptidases A; D015032:Zinc