title: Morphometry and elemental analysis of rat exocrine pancreas following administration of trypsin inhibitor.
abstract: The morphological responses of the exocrine pancreas of the adult male rat to soybean trypsin inhibitor (STI) were studied by ultrastructural morphometry and electron probe X-ray microanalysis. STI administered orally in drinking water for 14 days resulted in a 72% increase in the wet weight of the pancreas. This enlargement was due, largely, to an increase in acinar cell mass. Volume increases in the acinar cell mass and extra-acinar cell compartment were 72 and 30%, respectively. The estimated total number of acinar cells in the mean exocrine pancreas was 500 million in the control and 630 million in the experimental group, representing an increase of 27%. Acinar cell volume was 1,790 microns 3 for the control and 2,457 microns 3 for the STI group. The pronounced morphometric changes of the organelles in the STI group were: the mean nucleolar volume increased by 56%; the volume of zymogen granular mass per cell increased by 93%; the volume of the Golgi complex and the condensing vacuoles per cell increased by 52 and 100%, respectively, whereas the membrane area of the Golgi complex and the condensing vacuoles increased by 98 and 47%, respectively. Spectral analysis of seven elements (Na, Mg, P, S, Cl, K and Ca) showed significant changes for nuclei, zymogen granules and mitochondria following STI: nuclei showed Na, P, K increased; zymogen granules showed Na, P, S, K increased, Cl decreased; mitochondrial particles showed Mg, P, Cl, Ca increased, and the mitochondrial matrix showed S decreased. The persistent uptake of STI probably resulted in a continual release of a trophic hormone acting on pancreatic tissue components, consequently causing hyperplasia and hypertrophy of the exocrine pancreas to accommodate a heightened demand for synthesis of exportable proteins.
authors.affiliation: Department of Cell Biology and Anatomy, New York Medical College, Valhalla.
authors.forename: T
authors.initials: T
authors.lastname: Sato
authors.forename: L
authors.initials: L
authors.lastname: Herman
mesh_terms: D000818:Animals; D002118:Calcium / Q000032:analysis*; D002712:Chlorides / Q000032:analysis*; D004577:Electron Probe Microanalysis; D008274:Magnesium / Q000032:analysis*; D008297:Male; D008854:Microscopy, Electron; D010179:Pancreas / Q000032:analysis / Q000166:cytology / Q000187:drug effects*; D010758:Phosphorus / Q000032:analysis*; D011188:Potassium / Q000032:analysis*; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000032:analysis*; D013455:Sulfur / Q000032:analysis*; D014360:Trypsin Inhibitor, Kunitz Soybean / Q000494:pharmacology*; D014361:Trypsin Inhibitors / Q000494:pharmacology*
chemical_list: D002712:Chlorides; D014361:Trypsin Inhibitors; D010758:Phosphorus; D013455:Sulfur; D014360:Trypsin Inhibitor, Kunitz Soybean; D012964:Sodium; D008274:Magnesium; D011188:Potassium; D002118:Calcium