PANCREAS AND DIABETES Valerija Vrhovnik Mentor: A. Žmegač Horvat

Anatomy of pancreas Anatomy of pancreas head head body body tail tail acinar cells acinar cells islets of Langerhans islets of Langerhans pancreatic duct pancreatic duct

Pancreas: dual-function gland Exocrine pancreas (acinar cells): Exocrine pancreas (acinar cells): produces digestive enzymes (trypsin produces digestive enzymes (trypsin, chymotrypsin, pancreatic lipase and amylase ) enzymes help further breakdown of carbohydrates, proteins, and fat enzymes help further breakdown of carbohydrates, proteins, and fat

Endocrine pancreas Islets of Langerhans 4 types of cells: Islets of Langerhans 4 types of cells: 1) Alpha cells – produce glucagon (hormone); 25% total cells 25% total cells 2) Beta cells – insulin synthesis and secretion; 60% secretion; 60% 3) Delta cells – produce somatostatin (inhibits secretion of other hormones); 10% secretion of other hormones); 10% 4) PP cells – secrete pancreatic polypeptide; <5% polypeptide; <5%

Insulin = hormone of feasting small protein composed of two peptide chains small protein composed of two peptide chains

Insulin effect on metabolism 1) Carbohydrates: ↑ glucose utilization, ↑ 1) Carbohydrates: ↑ glucose utilization, ↑ CHO storage, use of CHO for energy CHO storage, use of CHO for energy 2) Fats: ↓ use of fat, fat sparer 2) Fats: ↓ use of fat, fat sparer 3) Proteins: ↑ protein anabolism, inhibits 3) Proteins: ↑ protein anabolism, inhibits catabolism catabolism

Factors Regulating Insulin Secretion 1) High plasma glucose levels – insulin secreted to return glucose levels back to normal 2) High plasma amino acids – after a high protein meal, arginine and lysine stimulate beta cells to increase insulin secretion 3) Fatty acids and ketone bodies – increases secretion

Diabetes mellitus Type 1 – juvenile diabetes: Type 1 – juvenile diabetes: loss of insulin-producing beta cells leading to a deficiency of insulin loss of insulin-producing beta cells leading to a deficiency of insulin Type 2 – maturity onset: Type 2 – maturity onset: insulin resistance - cells fail to use insulin properly insulin resistance - cells fail to use insulin properly the most common type the most common type

Causes: heredity - stronger inheritance pattern for type 2 heredity - stronger inheritance pattern for type 2 type 1 appears to be triggered by some (mainly viral) infections (e.g. Coxackie virus) type 1 appears to be triggered by some (mainly viral) infections (e.g. Coxackie virus) obesity – type 2 obesity – type 2

Symptoms: 1) Polyuria (excess urine production) 2) Polydipsia (excess drinking of water) 3) Polyphagia (excessive eating) 4) Loss of weight 5) Asthenia (lack of energy)

Complications: Diabetic cardiomyopathy Diabetic cardiomyopathy Diabetic nephropathy Diabetic nephropathy Diabetic neuropathy Diabetic neuropathy Diabetic foot Diabetic foot Diabetic retinopathy Diabetic retinopathy

Treatment: Diabetes type I: Diabetes type I: artificial insulin – subcutaneous injection artificial insulin – subcutaneous injection insulin control, diet, weight control and exercise insulin control, diet, weight control and exercise

Diabetes type II: Diabetes type II: diet, weight loss diet, weight loss exercise to increase receptor responsiveness exercise to increase receptor responsiveness sulfonylureas to increase number of receptors sulfonylureas to increase number of receptors