PANCREAS AND DIABETESPANCREAS AND DIABETES

Valerija Valerija VrhovnikVrhovnik

Mentor: A. Žmegač Mentor: A. Žmegač HorvatHorvat

Anatomy of pancreasAnatomy of pancreas• headhead• bodybody• tailtail• acinar cellsacinar cells• islets of Langerhansislets of Langerhans• pancreatic ductpancreatic duct

Pancreas: dual-function Pancreas: dual-function glandgland

• Exocrine pancreas (acinar cells):Exocrine pancreas (acinar cells):•produces digestive enzymes (trypsinproduces digestive enzymes (trypsin,

chymotrypsin, pancreatic lipase and amylase )

•enzymes help further breakdown of enzymes help further breakdown of carbohydrates, proteins, and fatcarbohydrates, proteins, and fat

Endocrine pancreasEndocrine pancreas

• Islets of LangerhansIslets of Langerhans 4 types of cells:4 types of cells:1) 1) Alpha cellsAlpha cells – produce glucagon – produce glucagon (hormone); (hormone);

25% total cells25% total cells2) 2) Beta cellsBeta cells – insulin synthesis and – insulin synthesis and

secretion; 60%secretion; 60%3) 3) Delta cellsDelta cells – produce somatostatin – produce somatostatin (inhibits (inhibits

secretion of other hormones); 10%secretion of other hormones); 10%4) 4) PP cellsPP cells – secrete pancreatic – secrete pancreatic

polypeptide; <5%polypeptide; <5%

Insulin = hormone of Insulin = hormone of feastingfeasting

• small protein composed small protein composed of two peptide chainsof two peptide chains

Insulin effect on metabolismInsulin effect on metabolism

• 1) Carbohydrates: ↑ glucose utilization, 1) Carbohydrates: ↑ glucose utilization, ↑ ↑

CHO storage, use of CHO for energyCHO storage, use of CHO for energy

• 2) Fats: ↓ use of fat, fat sparer2) Fats: ↓ use of fat, fat sparer

• 3) Proteins: ↑ protein anabolism, 3) Proteins: ↑ protein anabolism, inhibitsinhibits

catabolismcatabolism

Factors Regulating Insulin Factors Regulating Insulin SecretionSecretion

1)1)High plasma glucose levels High plasma glucose levels – insulin – insulin secreted to return glucose levels back to secreted to return glucose levels back to normalnormal

2) High plasma amino acids 2) High plasma amino acids – after a – after a high protein meal, arginine and lysine high protein meal, arginine and lysine stimulate beta cells to increase insulin stimulate beta cells to increase insulin secretion secretion

3) 3) Fatty acids and ketone bodies Fatty acids and ketone bodies – – increases secretionincreases secretion

Diabetes mellitusDiabetes mellitus• Type 1 – juvenile Type 1 – juvenile

diabetesdiabetes::• loss of insulin-producing loss of insulin-producing

beta cells leading to a beta cells leading to a deficiency of insulin deficiency of insulin

• Type 2 – maturity Type 2 – maturity onsetonset::

• insulin resistance - cells fail insulin resistance - cells fail to use insulin properly to use insulin properly

•the most common type the most common type

Causes:Causes:• heredityheredity - stronger inheritance - stronger inheritance

pattern for type 2 pattern for type 2

• type 1 appears to be triggered by type 1 appears to be triggered by some (mainly viral) some (mainly viral) infections infections (e.g. Coxackie virus)(e.g. Coxackie virus)

• obesity obesity – type 2– type 2

Symptoms:Symptoms:

1) 1) PolyuriaPolyuria (excess (excess urine production)urine production)

2) 2) PolydipsiaPolydipsia (excess drinking of (excess drinking of water)water)

3) 3) PolyphagiaPolyphagia (excessive eating)(excessive eating)

4) 4) Loss of weightLoss of weight5) 5) AstheniaAsthenia (lack of (lack of

energy) energy)

Complications:Complications:

• Diabetic Diabetic cardiomyopathycardiomyopathy

• Diabetic nephropathyDiabetic nephropathy

• Diabetic neuropathyDiabetic neuropathy

• Diabetic footDiabetic foot

• Diabetic retinopathyDiabetic retinopathy

Treatment:Treatment:• Diabetes type I:Diabetes type I:

•artificial insulin – subcutaneous injectionartificial insulin – subcutaneous injection

• insulin control, diet, weight control and insulin control, diet, weight control and exerciseexercise

• Diabetes type II:Diabetes type II:•diet, weight lossdiet, weight loss

•exercise to increase receptor exercise to increase receptor responsivenessresponsiveness

•sulfonylureas to increase number of sulfonylureas to increase number of receptorsreceptors