[Experimental pancreatitis of ductal origin. Anatomo-pathologic and ultrastructural study].

The injection of bile under low pressure led in 21 dogs out of 30 to a process of acute pancreatitis and to the reproduction of the different histopathological types of pancreatitis seen in man. This represents a weighty argument in favour of the concept of oedematous pancreatitis, interstitial pancreatitis with sometimes major cytosteatonecrosis and necrosing pancreatitis as different manifestations of the same disease, which is not universally accepted. Our research has once again emphasized the fact that the interstitial phenomena and in particular fatty necrosis precede parenchymatous necrosis. Morphological studies were used to attempt to define the link between fat necrosis and acinar necrosis. Light microscopy showed that there was no topographic evidence of direct involvement of the acinar cell in contact with fat necrosis. By contrast, ultrastructural studies revealed initial involvement of the basal pole of the acinar cell. This would emphasize the responsibility of interstitial phenomena in the maintenance, if not the induction, of acinar necrosis. It cannot be excluded that fat necrosis could indirectly, via the liberation of factors carried by oedema, play a role in these phenomena of acinar necrosis. In addition, it was noted that the apical poles of the acinar cells did not seem to be damaged, the acinar lumina were dilated and there was loss of the intercellular junctions. This would hence indicate the possible passage into the interstitium of a toxic substance (bile salts, enzymes liberated in excess) coming directly from the acinar lumina.