Morfološke promene egzokrinog pankreasa pacova izazvane insulinom

Abstract

Egzokrini i endokrini pankreas ostvaruju složenu anatomsku i funkcijsku interakciju. Naime, egzokrini deo pankreasa je pod uticajem hormona endokrinog, ne samo sistemski kao ostale ćelije organizma, već i direktno, preko veze portnog sistema acinusa i Langerhansovog ostrvca. Pokazano je da i endogeni i egzogeni insulin izazivaju povećanu sintezu pankreasnih enzima u acinusima, a time i njihov rast. Veza strukturnog (ćelijskog/tkivnog) i funkcijskog odgovora egzokrinog pankreasa na periportalni nivo insulina ukazuje na visok i kompleksan stepen insulo-acinusne interakcije u fiziološkim, a pogotovo u patološkim stanjima. Cilj ove doktorske disertacije je da istraži histološke promene egzokrinog pankreasa i ultrastrukturne promene acinusnih ćelija tokom remodeliranja izazvanog insulinom. U eksperimentu su korišćeni Wistar pacovi, starosti dva meseca. Pacovi su podeljeni u šest grupa, četiri grupe su primale i.p. nisku (0.4 IU) ili visoku (4 IU) dozu insulina, jedan (akutno) ili tri dana (hronično). Preostale dve grupe na isti način primale su fiziološki rastvor i predstavljale su odgovarajuće kontrole. Tri sata nakon poslednjeg tretmana, sve životinje su žrtvovane dekapitacijom. Odmah nakon žrtvovanja, pankreas je izolovan, slikan, izmeren i odvojen za svetlosnui elektronsku mikroskopiju. Efekti insulina na histološke promene egzokrinog pankreasa analizirane su svetlosnom mikroskopijom (hematoksilin/eozin bojenje, AZAN), fraktalnom analizom, imunohistohemijom (amilaza, pHH3 – fosforilisana forma histona H3 (eng. PhosphoHistone H3), Ki-67 i PCNA – nukleusni antigen proliferišućih ćelija (eng. Proliferating Cell Nuclear Antigen)) i elektronskom mikroskopijom (volumenska gustina citoplazme, dijametar i volumenska gustina zimogenih granula, broj i volumenska gustina nukleusa)...

Exocrine and endocrine pancreas achieves complex anatomical and functional interaction. Namely, the exocrine part of the pancreas is influenced by the endocrine hormone, not only systemically as other cells in organizm, but also directly, via the islet acinar portal vascular system. It has been shown that both endogenous and exogenous insulin cause an increased synthesis of pancreatic enzymes in the acinus and hence their growth. The relationship between the structural (cellular/tissue) and functional response of exocrine pancreas to the periportal level of insulin indicates a high and complex level of insulin-acinus interaction in the physiological and especially in the pathological state. The goal of this doctoral dissertation was to investigate the histological changes of exocrine pancreas and ultrastructural changes of acinar cells during insulininduced remodeling. Two-month-old male Wistar rats were used. Rats were divided into six groups, four groups were treated i.p. with low (0.4 IU) or high (4 IU) dose of insulin, one (acutely) or three (chronically) days. The other two groups, in the same way, were received 0.9% saline solution and served as a corresponding control. Three hours after the last injection, the animals were sacrificed by decapitation. Immediately after sacrificing, the pancreas was isolated, pictured, weighted and prepared for light and electron microscopy. The effect of insulin on the histological changes of exocrine pancreas was analyzed by light microscopy (hematoxylin/eosin staining, AZAN), fractal analysis, immunohistochemistry (amylase, pHH3, Ki67 and PCNA) and electron microscopy (volume density of cytoplasm, diameter and volume density of zymogene granules, as well as number and volume density of nuclei). Discrete changes in the histological structure of exocrine pancreas were observed in insulin treated animals which are reflected in more connective and fat tissue near the excretory ducts and blood vessels...