Developmental Regulation of the Porcine Exocrine Pancreas by Glucocorticoids

Abstract

SummaryThe possible role of Cortisol in development of the exocrine pancreas was investigated. In the first study, fetal pigs were removed from the uterus by caesarean section (pentobarbitone anesthesia) and the pancreas collected from 51 69 to 109‐day‐old fetuses (term = 114 % 2 days). Of these, 15 88 to 90‐day‐old fetuses had been infused subcutaneously for 6 days with either saline, adrenocorticotropic hormone or Cortisol (osmotic mini‐pumps implanted at 82–84 days). The pancreas was also removed from eight newborn pigs. Quantitative enzyme analysis showed that amylase and trypsin activities per milligram pancreatic protein increased toward term, correlated positively with fetal plasma Cortisol (p < 0.01) and were stimulated by Cortisol infusion (p < 0.05). In the second study, pigs were delivered by caesarean section 2–3 days before term (to circumvent the neonatal Cortisol surge) and injected intramuscularly with saline (n = 11), metyrapone (an inhibitor of Cortisol synthesis, n = 12), adrenocorticotropic hormone (n — 14) or Cortisol acetate (< = 6) during the postnatal period. At 6–7 days of age, adrenocorticotropic hormone‐ and Cortisol acetate‐treated pigs had higher concentrations of amylase and trypsin in pancreas than metyrapone‐treated pigs. The values in saline‐injected pigs were intermediate. By gel electrophoresis and subsequent incubation with enzyme substrates, protease E, chymotrypsin C, and cathodic trypsin were first detected at 6–7 days of age, and the activities (semiquantitative densitometry) appeared lower in metyrapone‐treated pigs than in pigs from other treatment groups. The results indicate that glucocorticoids stimulate the perinatal development of pancreatic enzymes in the pig. In species that have a relatively mature gut at birth (e.g., pig, human), developmental regulation by glucocorticoids may be most important in the period immediately before and after birth.