Guest guest Posted July 11, 2003 Report Share Posted July 11, 2003 E, Can you explain how the feedback loop (if there is one) works for the pancreatic enzymes that are used in the S.I. and then flushed out.. The reason I ask, is partly b/c I am curious about the idea how supplementation of enzymes somehow could inhibit the pancreatic production.. -Jason Quote Link to comment Share on other sites More sharing options...
Guest guest Posted July 11, 2003 Report Share Posted July 11, 2003 Can you explain how the feedback loop (if there is one) works for the pancreatic enzymes that are used in the S.I. and then flushed out.. The reason I ask, is partly b/c I am curious about the idea how supplementation of enzymes somehow could inhibit the pancreatic production..-Jason Hi Jason, No, I know of no feedback loop specifically for ingesting dietary enzymes. The normal feedback loop for pancreatic juice production and secretion requires food to leave the stomach after digestion in the stomach. The neural and endocrine feedback may be considered. Cranial nerve X, the vagus nerve, carries both sensory and parasympathetic motor impulses in a reflex known as a vagovagal reflex. (Kind of fun to say ... vagovagal.) That's the neural stimulation of the pancreas. Also CCK is the endocrine stimulus for enzyme synthesis/release from the pancreatic acinar cells while secretin is the endocrine stimulus for the bicarbonate release from the pancreatic duct cells. Both the pancreatic duct along with the common bile duct flow through the sphincter of Oddi into the proximal portion of the duodenum. Acidic chyme from stomach emptying is the stimulus for all of this to happen. You should be able to read about it in your physiology text. One of my favorite texts is by Berne and Levy. I'm not home right now, but I think the title is either Physiology or Medical Physiology. It's the text used at UCSF as well as University of Texas medical schools in the 12 graduate unit physiology course. I do seasonal pilgrimages to the UCSF bookstore and spend prohibitive amounts of cash on books. I lead a rather simple life wherein my major forms of entertainment are forest running, tai chi and cooking (along with eating!!) So I salve my conscience regarding spending too much money on books that it's the only thing I spend money on aside from food, running shoes and Chinese herbs. So the conclusion is that I don't think eating dietary enzymes turns off any of the pancreatic juice stimulation. There is no mechanism for the products of the pancreas to feedback on itself. The mechanism of pancreatic stimulation would be positive feedback from presence of small intestine contents until the small intestine empties. Positive feedback is less common than negative feedback homeostasis in the human body, but another example is childbirth wherein oxytocin gets further stimulated by subsequent uterine contractions. Thus, Thanksgiving Dinner is one of the ways that males get to very slightly experience the positive feedback of uterine labor. Just kidding! ;-) Emmanuel Segmen Quote Link to comment Share on other sites More sharing options...
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