Dr. Pooja G

1. Effect of Alcohol on Pancreas
Pooja Goswami
AI.I.M.S. New Delhi

2. Point to be covered
• Pancreas normal physiology and anatomy
• Exocrine & endocrine function of pancreas
• Epidemiology
• Different hypothesis for pancreatitis
• Effect of alcohol on pancreas
• Effect of alcohol on PSCs
• Role of PSCs in fibrosis or cancer progression

4. Pancreas
• Anatomy
– Endocrine
• Pancreatic islets produce insulin and glucagon
– Exocrine
• Acini produce digestive enzymes
– Regions: Head, body, tail

5. Normal Pancreas
• The pancreatic gland contains three major types of
cells.
• The ductular cells make up about 10% of the
pancreas and secrete solutions rich in bicarbonate.
• The acinar cells comprise over 80% of the pancreas
and they synthesize and secrete pancreatic enzymes.
• The islet cells make up about 10% of the pancreas
and form the endocrine portion of the pancreas. These
cells secrete the hormones insulin, glucagon,
somatostatin, and pancreatic polypeptide.

6. Islet cells
– Alpha cells secrete glucagon-elevates
blood glucose
concentrations
– Beta cells secrete insulin-reduces
blood glucose
concentrations
– Delta cells secrete somatostatin- slows the rate of
food absorption and digestive enzyme secretion

7. Pancreatic enzyme

8. Exocrine & Endocrine function of Pancreas
Exocrine Endocrine
1. Occurs in the islets of Langerhans
2. Beta cells secrete insulin
3. Alpha cells secrete glucagon
4. Delta cells secrete somatostatin
1. The acinar cells secrete amylase,
proteases, and lipases, enzymes
responsible for the digestion of 3 food
types: carbohydrate, protein, and fat.
2. Trypsin is the most abundant enzyme
3. Stored in its inactive form, trypsinogen;
activated by enterokinase

9. Alcohol & Pancreatitis
• Alcohol abuse accounts for 38-94% CP
• Daily 80g/day for 13-21 years to develop
alcohol induced pancreatitis
• Only 10 % of heavy drinker develop
pancreatic inflammation
• Black ppl are 3-4 times more chances to
develop pancreatitis
• Patient get diagnosed at age of 35-40 years of
age

10. Ductal obstruction hypothesis
• Chronic alcohol use
• acinar and ductal cell
• protein rich pancreatic juice, low in volume and HCO3
• formation of protein precipitates – plug
• calcification of ppt – ductal stone formation
• ductule obstruction
• parenchymal damage
• Pancreatic ductal stone are seen in alcoholic, tropical, hereditary,
idiopathic
• Histologic changes of CP may be seen with out ductal obstruction

11. Toxic metabolic hypothesis
• (alcohol) Direct injurious effect on acinar and ductal cells
• Increased membrane lipid peroxidation (oxidative stress),
free radical production
• Increase acinar cell sensitivity to pathogenic stimuli
• Activation of pancreatic stellate cells (alcohol, cytokines) –
produce proteins of extracellular matrix

12. Necrosis fibrosis hypothesis
• Repeated episodes of acute pancreatitis with cellular
necrosis or apoptosis, healing replaces necrotic tissue with
fibrosis
• Evidence from natural history studies - more severe and
frequent attacks
• More evidence from hereditary pancreatitis and
animal models
• But some have evidence of chronic pancreatitis at
time of first clinical acute attack

13. Genetics Basis of CP
Autosomal dominant disorder
Cationic Trypsinogen gene mutation….PRSS1(R122H)
Autosomal Recessive….CFTR mutation
Susceptabilty gene….SPINK1
Course Modifiers…..various polymorphisms
(ADH2,ADH3,ALDH2,CYP2E1 ETC.)

14. Distribution of ALDH genotypes with age at
onset of Alcoholic Pancreatitis
41
40
39
38
37
36
35
34
38.5 ± 3
Allele Type
Mean Age (in years)
40.76 ± 8
34.71 ± 10
2-1 2-1 2-1 2-2 2-2 2-2
It appears that
 When genotype 2-2/is conferring risk ( double dose of
Lys; allele 2-2 *)
 But when genotype 2-1/2-2 (heterozygous) is conferring risk (single
dose of Lys; allele 2-2 *)
 When genotype 2-1/2-1 is present (absence of allele 2-2 *)
 onset of pancreatitis is slightly delayed
 onset of pancreatitis is significantly delayed
 onset of pancreatitis occurs at younger age

15. Alcohol and Pancreas
• Incompletely understood and intensely
studied.
• Why 10% heavy alcoholics develop chronic
pancreatitis and the rest not, or limited to
asymptomatic pancreatic fibrosis

16. How alcohol affect pancreas
• Earlier theories suggested pancreatic duct is the
central organ to develop alcohol induced pancreatitis
• New theory evolved, alcohol have direct effect on
acinar cell as well as PSCs

17. Mechanism of ethanol induced Pancreas
dysfunction
• Ethanol & other factors combined affect
– Pancreatic blood flow
– Pancreatic exocrine secretion
– Pancreatic duct permeability
– Zymogen activation
– Intracellular signaling
– Oxidative stress generation
– Interaction of ethanol and its metabolite

18. Spasm in sphincter of oddi causes
• The sphincter of Oddi separates the
common bile duct & pancreatic duct
from the small intestine. So by
relaxing it, bile and pancreatic juices
can be dumped into the small
intestine.
• Digestive enzyme of pancreas
instead of entering to intestine to
digest food, “ digest” pancreatic cell
• Backflow of bile or duodenum
content back into the pancreatic duct
lead

19. Effect of alcohol on small duct
• Small pancreatic duct
begins at the acini and
drain into large
pancreatic duct
• Small duct blocked by
protein plug formation
• Protein plug get enlarge
and calcify, which may
be a cause or effect of
disease
Freedman at al 1993

20. Protein plug: pancreatic digestive enzyme and
lithostathine & GP2
• Pancreatic Lithostathine
– Form 5-10% protein of pancreatic secretion
– Inhibit the deposition of ca+ from pancreatic juice, therfore
its ↓ level promote calcification of protein (Bernard et al
1992)
– Convert lithostathine into lithostathine S1( to initiate plug
formation
– Long term alcohol consumption leads to ↑ conc. of
lithostathine in juice, which promotes protein deposition in
ducts (Apte et al 1996)
• Pancreatic GP2
– Help in protein precipitation from pancreatic juice
– Alcohol consumption lead to ↑ conc. of GP2, favor plug
formation

21. Effect of protein plug formation on
pancreas
• Protein plug formation or stone in small duct
lead to ulceration, scarring further obstruction
& finally atrophy and fibrosis via
– Reduces pancreatic secretion
– Increased viscosity of secretion
– Decrease citrate conc. In pancreatic juice, a
predisposing factor for crystal formation
– Producing protein to increase stone formation
Protein plug known to be a player in progression of disease if not initiation

22. Direct effect of alcohol on acinar cell
• A single acinar cell can
synthesize 10 million
enzyme mol/day
• They protect themselves by
synthesizing most digestive
enzymes (trypsin) as
inactive precursor i.e.
zymogen granule
• Any disruption could lead to
premature activation of
zymogen & causes auto-digestion
of pancreatic
acinar cells whitcomb et al 1996

23. Effect of alcohol on fragility of zymogen & lysosome
• Long term alcohol
consumption premature
activation of zymogen
enzyme
• Alcohol ↑ the synthesis of
digestive enzyme
• Alcohol consumption lead
to↑ in fragility of lysosome &
zymogen granule allowing
zymogen leakage to the cell
Wilson et al 1992, Apte et al 1995

24. How fragility start auto-digestion of pancreas
• Alcoholic metabolites makes fragile zymogen granule &
lysosomal membrane
• Trypsin can not be degrade by protective enzyme of acinar
cell
• So due to fragile membrane lysosomal enzyme (cathepsin B)
will active trypsin to trypsinogen which further lead to activate
other enzyme & start the cascade of event or autodigestion of
pancrease
L Z
Trypsinogen Trypsin
Cathepsin B
Activate other enzyme and strat
autodigestion of pancreas

25. Ethanol Metabolism
Ethanol Metabolism
Non-oxidative Pathway
Oxidative Pathway
Rate is 21 fold higher
Alcohol dehydrogenase
Cytochrome P-4502E1 (CYP2E1)
Catalse FAEE synthases
Acetaldehyde ROS
FAEE
Induces morphological
Alteration in pancreas
Harmful to cell membrane,
intracellular protein & DNA
lysosomal fragility

26. Alcohol induced oxidative stress in pancreas
• The cell is normally protected from the disruptive effect of free
radicals by antioxidant system, which releases during normal
metabolism of alcohol via CYP2E1
• Oxidative stress is the imbalance between production of ROS &
defense mechanism (Antioxidant glutathione, peroxidase,
superoxide mutase & catalase)
• This imbalance may be a due to
– ROS release during ethanol oxidation via CYP2E1
– Depletion of ROS scavenger gluthathione
• As a result oxidative stress destabilizes zymogen & lysosome
granules lead to auto digestion of pancreas via acinar cell activation
•
Altomare et al 1996

27. Effect of alcohol metabolism on pancreas
• Acetaldehyde induces the stellate cells & lead
to fibrosis
• FAEE induces the acinar cell & lead to
necrosis and continuous insult lead to fibrosis

28. Alcoholic Chronic Pancreatitis
ALCOHOL
Oxidative pathway
Acetaldehyde
Non-oxidative pathway
Fatty acid ethyl esters
(FAEEs)
Pancreatic Stellate Cell Activation

29. Pancreatic stellate cells (PSCs)
• PSCs are 4% cell of total pancreatic cell
• Vit A containing lipid droplets
• On activation loose vitamin A
– Maintained matrix turn over
– Protective immune function as phagocytic cell
– Work as progenitor cell (in acute injury secrte
insulin after differentiation)
– CCK (Cholecystokinin ) induced pancreatic
exocrine function

30. Stellate cells
Quiscent PSc Active PSc
Vitamin A lipid droplets Present Absent
a Smooth muscle actin Absent Present
Proliferation Limited Increased
Migration Limited Increased
ECM Limited Increased
MMPs and TIMPs Maintain normal ECM
turnover
Change in types of MMPs and
TIMPs to facilitate ECM
deposition
Production of cytokines Limited Increased ((PDGF, TGFb, CTGF,
IL1, IL6, IL15)
Capacity for phagocytosis Absent Present

31. Stellate cells formation, proliferation &
Active
PSc
migration
PDGF induced Proliferation mediated by ERK & JAK/STAT
•PDGF induced migration mediated by PI3K
•Migration also mediated by hedgehog pathway
Quiscent
PSc
TGFB mediated
LPS receptor
(TLR 2 &4)
SMA positve

32. PSCs Activation
• PSCs are activated via paracrine
pathways by exogenous factors
such as cytokines, oxidant stress,
ethanol and its metabolites
• Activated PSCs secrete cytokines
which act on PSC in autocrine
way
• These remain active PSCs even in
the absence if the initial trigger
factors, leading to excessive
ECM production and eventually
causing pancreatic fibrosis
Active
PSC
Quiescent
PSC
Cytokine autocrine
effect
Pancreatic
fibrosis

33. Activated PSCs leads to fibrosis
Active
PSC
Quiescent
PSC
Cell proliferation
SMA expression
ECM protein synthesis
Matrix degradation
via
Vit. A loss (Altered retinol metabolism)
Imbalance MMP/TIMP
Cell migration
Contractility
Pancreatic
fibrosis
Ethanol insult &
Endotoxin
Mainly acetaldehyde
LPS ↑ in blood of alcoholics

34. PSC in Chronic Pancreatitis: Animal
studies
• Fibrosis has been produced in rat model via
(1) trinitrobenzene sulfonic acid (TNBS) injection into the pancreatic
duct (Haber et al., 1999)
(2) intravenous injection of an organotin compound dubutyltin chloride
(DBTC) (Emmrich et al., 2000)
(3) spontaneous chronic pancreatitis in WBN/Kob rats (Ohashi et al.,
1990)
(4) severe hyperstimula- tion obstructive pancreatitis (SHOP),
involving intraperitoneal (IP) injections of supramaximal doses of
caerulein (a synthetic analogue of CCK, a major pancreatic
secretagogue) + bile- pancreatic duct ligation (Murayama et al.,
1999)
(5) repeated IP injections of a superoxide dismutase inhibitor
(Matsumura et al., 2001)

35. Continued..
• (6) intragastric high dose alcohol administration + repeated
caerulein injections (Tsukamoto et al., 1988; Uesugi et al.,
2004)
• (7) chronic alcohol administration (liquid diet) with repeated
cyclosporin and caerulein injections (Gukovsky et al., 2008)
• (8) chronic alcohol administration with repeated endo- toxin
LPS, injections (Vonlaufen et al., 2007b).
•Rat model produced by chronic alcohol administration and
repeated endotoxin exposuren that is based on a well recognized
clinical phenomenon, namely endo- toxinaemia (secondary to
increased gut mucosal permeability) in alcoholics (Bode et al.,
1993; Parlesak, 2005).
•Thus, the alcohol feeding, LPS challenge model possibly
represents the most physiologically relevant model of chronic
alcoholic pancreatitis described to date.

36. Pancreatic fibrosis
Lost vitamin A

37. Inflammation towards PDAC

38. THANK YOU FOR YOU ATTENTION