Pancreatic Secretion

What is the major stimulus for release of pancreatic enzymes?

CCKa Gastrin=minor

What is the mutation associated with Cystic Fibrosis?

delta508 deletion in NBD1 of the CFTR

Name 2 molecules that activate inactive precursors from the pancreas.

1. Enteropeptidase in duodenum 2. Trypsin-positive feedback loop Trypsin inhibitor inhibits it

In the intestinal phase, what activates acinar cells to release enzymes?

1. MAJOR=CCK from I cells, stimulated by Fat 2. MINOR=Secretin and vago-vagal reflex

In the intestinal phase, what activates duct cells to release HCO3-?

1. MAJOR=Secretin from S cells-stimulated by H+ 2. MINOR-Vago-vagal reflex from CCK and H+/fat in SI

Explain the pathway of the "plasma like" primary secretion?

1. Na/K pump pushes Na+ into IS, leading to Na returning thru cotrnasporter 2. Cotransporter brings in Cl- and K+ 3. K+ leaves via K+ channels on its own 4. Cl- builds up in cell and gradient pushes it into acinar lumen via apical channels

What makes up the secretin stimulated secretion?

1. Na=155mM 2. Cl-=40 mM- really LOW 3. HCO3-=115mM- really HIGH 4. k+=7mM

What is the most powerful stimulus for HCO3- secretion? minor stimulus?

1. Secretin-->activates AC-->raises cAMP-->stimulates PKA-->phosphorylates CFTR 2. Ach-->activates Gq-->stimulates PC-->releases DAG (PKC up) and IP3 (Ca release)

Name 5 zymogens-inactive precursors secreted from the pancreas.

1. Trypsinogens 2. Chymotrypsinogens 3. Procarboxypeptidase A, B 4. Proelastase 5. PLA2-->Fats, rest are for proteins

Name 5 active enzymes secreted by the pancreas.

1. a-Amylase-->Carbs 2. Lipase, colipase, carboxyl ester lipase-->Fats 3. DNAase-->break up DNA

What is the "plasma-like" secretion of pancreatic juice?

Basal secretion

What is the conservation process at the end of the extralobular ductal system?

Cl-/HCO3- exchange HCO3- gets reabsorbed, while Cl- gets secreted High secretion rate=higher bicarbonate because of less time for reabsorption

What do CCK and Ach do in the acinar cell?

Potent stimulation of Cl- secretion by stimulating protein kinases that act on channels to activate them

What is the endocrine function of the pancreas?

Releases insulin and glucagon

What is the exocrine function of pancreas?

Secretes into lumen: 1. Digestive enzymes 2. HCO3 rich fluid, which carries enzymes

What occurs during the cephalic phase in pancreatic secretion?

Vagal stimulation of duct and acinar cells via M3 receptor