30.46. What is main link of pathogenesis of acute pancreatitis? What pathogenic variants of this disease do they distinguish?

Main mechanism of development of acute pancreatitis of any etiology is “proteolytic explosion” - premature activation of enzymes of pancreatic juice in ducts of pancreatic gland. The most important one is activation of formation of tripsine or formation of it from tripsinogen under influence of active proteolytic enzymes of cells (lyposomal) or intestinal origin. Peculiarity of activation of enzymes in ducts of pancreatic gland is that process has avalanche-like character, and if it forms in one place of gland it spreads to all its ducts. It is caused by proteolytic reactions, when molecules of active enzymes (tripsine, chimotripsine) transform non-active enzymes (tripsinogen, chimotripsinogen) into active form.

Initiation of acute pancreatitis needs “spark”, which can be even single molecules of active protease which entered ducts of gland from injured cells of intestines.

Depending on source of those protease and mechanisms of its entering to ducts they distinguish 3 pathogenic variants of acute pancreatitis:

1. Primary alterative

2. Hypertensive

3. Refluxe.

30.47. What is the characteristic for primary alterative variant of development of acute pancreatitis?

Primary alterative variant of acute pancreatitis develops as a result of injure of tissue of pancreas by different alterative factors it can be mechanical injure (trauma, surgical operations), influence of chemical factors (poisoning by alkalis, acids), biological factors (viruses, bacteria), ischemic or allergic injure.

Initiators of premature activation of enzymes are lysosomal enzymes from damaged cells of tissue of gland.

30.48. What can cause development of hypertensive variant of acute pancreatitis?

Hypertensive variant of acute pancreatitis develops because of increasing pressure of pancreatic juice in ducts of pancreas.

They distinguish two varieties of this variant due to reason of formed hypertension:

1. hypersecretory pancreatitis. Reason of increasing of pressure in ducts of pancreas is increasing of secretion of pancreatic juice (fatty food, alcohol, that stimulate formation of secretine and cholecystokinine-pancreosemine) when pancreatic ducts can’t let pass all pancreatic juice (relative deficiency of ducts). In this case physiological peculiarities of ducts of gland are important, that’s why pancreatitis in this form can arise not at all people

2. obturative pancreatitis. Hypertension in ducts of pancreas arises in case of normal level of secretion, but in case of presence of obstacles (obturations) for excretion of juice (stones, squeezing of ducts from outside)

Increased pressure causes injury of cells that lay on surface of ducts. It causes releasing of lysosomal enzymes and activation of autocatalytic mechanism (see question 30.46)

30.49. What conditions cause refluxe variant of pancreatitis?

Refluxe variant of pancreatitis arises as a result of entering into pancreatic ducts of duodenal contents or bile.

Duodenopancreatic reflux arises in case of increasing of intraduodenal pressure or relaxing of sphincter of Oddi. Initiator of premature activation of pancreatic enzymes is enterokynase - proteolytic enzyme, that is secreted by mucous membrane of duodenum.

Community of end of pancreatic and common bile duct is condition for formation of bile pancreatic reflux (common ampule) Bile acids that have detergents influence, when enter pancreatic ducts damage its cells. Lysosomal enzymes release from cells and launch process of activation of pancreatic juice. Also bile acids can activate lypase of pancreatic juice , but also there are facts that pancreatic lipase doesn’t need activation.