positive regulation of pancreatic juice secretion

Definition

Target type: biologicalprocess

Any process that increases the rate, frequency or extent of pancreatic juice secretion, the regulated release of pancreatic juice by the exocrine pancreas into the upper part of the intestine. [GOC:BHF, GOC:dph, GOC:tb]

Positive regulation of pancreatic juice secretion is a complex process that involves a cascade of signaling events, initiated by the arrival of food in the duodenum. This intricate interplay of hormones, neurotransmitters, and intracellular signaling pathways culminates in the release of digestive enzymes and bicarbonate ions from the pancreas, essential for efficient digestion.

The process begins with the detection of food entering the duodenum. This triggers the release of various stimuli, including:

* **Cholecystokinin (CCK):** A hormone released from the duodenum in response to the presence of fats and amino acids. CCK acts on the pancreas, stimulating the release of digestive enzymes like lipase, amylase, and protease.
* **Secretin:** Another hormone released from the duodenum, primarily in response to acidic chyme. Secretin acts on the pancreas, inducing the secretion of bicarbonate ions, which neutralize the acidic chyme, creating an optimal pH for digestive enzyme activity.
* **Acetylcholine (ACh):** A neurotransmitter released by the vagus nerve, which stimulates the release of both digestive enzymes and bicarbonate ions from the pancreas.

These stimuli activate specific receptors on pancreatic acinar cells and duct cells, leading to a series of intracellular signaling events:

* **CCK receptor (CCK-R) activation:** Binding of CCK to its receptor on acinar cells initiates a G protein-coupled signaling pathway. This pathway activates phospholipase C (PLC), leading to the production of inositol triphosphate (IP3) and diacylglycerol (DAG). IP3 promotes the release of calcium ions (Ca2+) from intracellular stores, while DAG activates protein kinase C (PKC). Both Ca2+ and PKC play crucial roles in the exocytosis of digestive enzymes from acinar cells.
* **Secretin receptor (SCTR) activation:** Secretin binds to its receptor on duct cells, triggering a signaling pathway that activates adenylyl cyclase, leading to the production of cyclic adenosine monophosphate (cAMP). cAMP activates protein kinase A (PKA), which in turn promotes the secretion of bicarbonate ions from duct cells.
* **Muscarinic acetylcholine receptor (mAChR) activation:** Acetylcholine binds to mAChRs on both acinar and duct cells, initiating signaling pathways similar to those activated by CCK and secretin, respectively.

The combined effect of these signaling pathways results in the release of pancreatic juice, containing a cocktail of digestive enzymes and bicarbonate ions. The precise composition of the juice varies depending on the type and amount of food ingested, ensuring optimal digestion of various dietary components.'
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Proteins (1)

Compounds (25)