how is pepsinogen activated in the stomach

Pepsin preferentially hydrolyzes peptide bonds containing the aromatic amino acids' amine group (tryptophan, phenylalanine, and tyrosine). From: Oral Delivery of Therapeutic Peptides and Proteins, 2022 View all Topics Add to Mendeley About this page Pepsin A These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc. These plants do not have digestive juices, but use the rot of the prey. While its not life-threatening, it can be serious. What is the purpose of this system? Gastric chief cells secrete pepsin as an inactive zymogen called pepsinogen. To make more pepsin, pepsin cleaves the 44 amino acids in pepsinogen. Pepsinogen - an overview | ScienceDirect Topics Pepsin is commonly used in the preparation of F(ab')2 fragments from antibodies. Functional cookies help to perform certain functionalities like sharing the content of the website on social media platforms, collect feedbacks, and other third-party features. gen. ( pep-sin'-jen) A proenzyme formed and secreted by the chief cells of the gastric mucosa; the acidity of the gastric juice and pepsin itself remove 42 amino acid residues from pepsinogen to form active pepsin. Historically, it has also been used as medicine in the form of laxatives when combined with Senna. 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Pepsin is an aspartic protease, using a catalytic aspartate in its active site. On exposure to an acidic pH the activation peptide is cleaved, thereby unmasking the active site and generating catalytically-active pepsin. [2] This type of cell also secretes gastric lipase enzymes, which help digest triglycerides into free fatty acids and di- and mono-glycerides. pepsinogen: [ pep-sino-jen ] a zymogen secreted by the chief cells of the gastric glands and converted into pepsin in the presence of gastric acid or of pepsin itself. Pepsin is a digestive enzyme. The safety of pepsin at high pH has important consequences for laryngopharyngeal reflux disease. Pepsin is essential for our digestive system and in turn our bodies as it helps break down proteins like eggs, meat, dairy, nuts, and seeds. It is a component of rennet used to curdle milk during the manufacture of cheese. Pepsinogen is also found in your pancreas. Why is pepsin important for our bodies? The gastric chief cell also contains many large secretory vesicles filled with digestive enzymes in the apical cytoplasm. These include the following: Pepsinogen deficiency can have a lot of underlying causes. It is used in the leather industry to extract hair and residual tissue from leather, as well as to retrieve silver from the abandoned photographic film by digesting the gelatin layer that stores the silver. Youll be advised to eat more of the following foods: Regular exercise helps to maintain your health and avoid diseases. The digestive power of pepsin is greatest at the acidity of normal gastric juice (pH 1.5-2.5). Our editors will review what youve submitted and determine whether to revise the article. An ulcer in the stomach is a type of stomach problem. Elevated intracellular levels of cyclic AMP: examples include secretin, vasoactive intestinal peptide and epinephrine. [37][38], Sucralfate, a drug used to treat stomach ulcers and other pepsin-related conditions, also inhibits pepsin activity.[39]. The cookie is used to store the user consent for the cookies in the category "Other. Inactive form of pepsin. Digestive System. 2022-10-13 Go to: Issues of Concern Pepsin depends on an acidic environment for protein digestion. The cookies is used to store the user consent for the cookies in the category "Necessary". This article was most recently revised and updated by, https://www.britannica.com/science/pepsin, National Center for Biotechnology Information - Physiology, Pepsin, Rockefeller Institute for Medical Research. In its active form, pepsinogen is called pepsin. Your email address will not be published. The pancreas is a small gland in your stomach. The secretion of pepsinogen synthesized from the transfected gene in AtT20 cells responds to cyclic AMP , indicating that pepsinogen is secreted via the regulated secretory pathway. Some of them include: If you have a low level of pepsinogen, your doctor will recommend surgery to raise your pepsinogen level. What is a stomach ulcer? Question: Determining enzyme activity Enzyme activity can be determined in the following ways: Check All That Apply by measuring how much of the enzyme is consumed by measuring how much of the substrate is consumed aces by measuring how much of the product is produced determining when the amount of substrate is equal . There are different methods to prepare pepsin which is mentioned as Pepsin is made by combining hydrochloric acid with minced stomach linings. Parietel cells, which release HCl, allow the conversion of pepsinogen (a zymogen) into pepsin. pepsin, the powerful enzyme in gastric juice that digests proteins such as those in meat, eggs, seeds, or dairy products. PTH plays an important role in regulating blood calcium levels by raising the amount of calcium in the blood. The pepsin can digest certain proteins and break them into smaller pieces in your stomach. The following enzymes/hormones are produced in the duodenum: Throughout the lining of the small intestine there are numerous brush border enzymes whose function is to further break down the chyme released from the stomach into absorbable particles. In the oral cavity, salivary glands secrete an array of enzymes and substances that aid in digestion and also disinfection. Know more about our courses. The pepsinogen enzyme is a common enzyme for stomach acid production in your body. Send comments to Richard.Bowen@colostate.edu, "I've got that yearning, burning, churning feeling inside me ", Hydrochloric acid is secreted from parietal cells, chymosin (rennin), a protease that coagulates milk protein, The Gastric Parietal Cell and the Mechanism of Acid Secretion. The following three genes encode identical human pepsinogen A enzymes: A fourth human gene encodes gastricsin also known as pepsinogen C: The P1 and P1' positions refer to the amino acid residues immediately next to the bond to be cleaved, on the carboxyl and amino side respectively. It is then transported to the small intestine and acts on the cells of the small intestine to slow the digestion of food. Pepsinogen is an: active enzyme that is released in the small intestine and digests carbohydrates. Some of these enzymes include: In carnivorous plants digestive enzymes and acids break down insects and in some plants small animals. Youll be asked about any medications that you take. Pepsin is a proteolytic enzyme released by chief cells, which are specialized in the stomach. Pepsin was named so after the Greek word. [3] Pepsins are the principal proteases in gastric secretions of adult mammals. The duodenum surrounds the pancreas, in the shape of a C and receives chyme from the stomach, pancreatic enzymes, and bile from the liver; this is the only part of the small intestines where Brunners glands are present on histology. They include the following: [1] The gastric chief cell (also known as a zymogenic cell or peptic cell) is a cell in the stomach that releases pepsinogen and chymosin. Amino acid residues 1 - 3 (Gln-Phe-Leu) of mature PI-3 bind to P1' - P3' positions of pepsin. The protein in our food is converted into amino acids and peptides by pepsin along with two other principal proteases of our body namely chymotrypsin and trypsin. Pepsin - Structure, Classification, Working, Application and Stability These enzymes are synthesized and secreted predominantly by chief cells in the gastric mucosa. What are some other benefits of pepsin? Pepsin is an endopeptidase enzyme that degrades proteins into peptides. Pepsin is found in pancreatic curd that condenses and twists during the processing of cheese. [20][21] Pepsin remains in the larynx (pH 6.8) following a gastric reflux event. In the stomach, gastric chief cells release pepsinogen. Hydrochloric acid is secreted by parietal cells in the stomach lining, which lowers the pH of the stomach. [10], In gastric tissue, a loss of parietal cells due to chronic inflammation has been shown to affect chief cell differentiation and can induce chief cells to transdifferentiate back into neck cells and can lead to the formation of mucus cell metaplasia known as spasmolytic polypeptide expressing metaplasia (SPEM) that could be precancerous. With this purpose in mind, they end up taking Pepsin supplements to ensure better assimilation of protein into their bodies. This cookie is set by GDPR Cookie Consent plugin. It does not store any personal data. These cookies track visitors across websites and collect information to provide customized ads. The only one of the enzymes listed that becomes activated in the presence of an acidic (low pH) environment is pepsinogen. Impulses from the vagus nerve and the hormonal secretions of gastrin and secretin stimulate the release of pepsinogen into the stomach, where it is mixed with hydrochloric acid and rapidly converted to the active enzyme pepsin. It can also turn pre-cooked cereals into instant hot cereals and change the plant protein used in non-dairy snacks. When food is consumed, the hormone gastrin and the vagus nerve trigger the release of pepsinogen and HCl from the stomach lining. Pepsin works best at temperatures between 37 and 42 degrees Celsius. Mosby Elsevier, 1st Ed. What Does It Mean To Put Out Of Commission? One must note that the role of pepsin is not only limited to digesting proteins in our food. While every effort has been made to follow citation style rules, there may be some discrepancies. This is why people who do not have a lot of pepsin need to take supplements to ensure the proper digestion of proteins in their bodies. Pepsinogen is produced in the stomach lining after being released from the stomach. You may be at an increased risk of developing other complications after this procedure. Pepsin is retained within the cell for up to 24 hours. Normally, the production of pepsinogen . Your email address will not be published. They are members of the family of aspartic proteases, and closely related to chymosin, another gastric protease expressed particularly in young animals. Pepsinogens are synthesized and secreted primarily by the gastric chief cells of the human stomach before being converted into the proteolytic enzyme pepsin, which is crucial for digestive processes in the stomach. The first site of protein digestion is stomach. download full PDF here, This enzyme was first discovered in 1936 by Theodore Schwann. What converts pepsinogen to pepsin? - BYJU'S Commercial pepsin is extracted from the glandular layer of hog stomachs. Pepsin enzymes are found in the stomach. Refer to the official website of Vedantu or download the app for an elaborate and comprehensive explanation. Pepsin remains in the larynx following a gastric reflux event. Some of the preceding endogenous enzymes have pharmaceutical counterparts (pancreatic enzymes) that are administered to people with exocrine pancreatic insufficiency. Hydrochloric acid creates an acidic environment, which allows pepsinogen to unfold and cleave itself in an autocatalytic fashion, thereby generating pepsin (the active form). [4][5][6][7] An acidic substance that was able to convert nitrogen-based foods into water-soluble material was determined to be pepsin. When activated, pepsinogen forms into pepsin which occurs in the stomach because of the (hydrochloric acid) present. The factors that convert Pepsinogen to Pepsin are: Pepsinogen is converted to pepsin which digests protein. The chief cells secrete pepsinogen in response to gastrin and especially ACh, and ACh also stimulates mucus secretion. Its a type of weight loss surgery. Pepsin is secreted by gastric chief cells as pepsinogen, an inactive zymogen. Corrections? 91 988-660-2456 (Mon-Sun: 9am - 11pm IST), Want to read offline? Pepsinogen is a powerful and abundant protein digestive enzyme secreted by the gastric chief cells as a proenzyme and then converted by gastric acid in the gastric lumen to the active enzyme pepsin. Pepsin is concerned with breaking down different proteins in our food. [2], Pepsin was one of the first enzymes to be discovered, by Theodor Schwann in 1836. All content on this website, including dictionary, thesaurus, literature, geography, and other reference data is for informational purposes only. Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree. The definition of pepsin is a digestive enzyme in the stomach that breaks down proteins into smaller units called polypeptides (or peptides for short). Parietal cells may secrete factors that lead to transdifferentiation of chief cells, so if lost, chief cells do not normally develop. It is formed in the chief cells of the stomach lining and is one of the most important digestive enzymes in humans and many other animals' digestive systems, where it aids in the digestion of proteins. These bodybuilders want to absorb more protein into their bodies and get rid of excess fat. This is because your body is used to digesting food with pepsin. In humans, pepsin concentrations in the stomach range from 0.5 to 1 mg/mL. The pepsin can digest certain proteins and break them into smaller pieces in your stomach. They are members of the family of aspartic proteases, and closely related to chymosin, another gastric protease expressed particularly in young animals. The hormone gastrin and the vagus nerve trigger the release of both pepsinogen and HCl from the stomach lining when food is ingested. Elevated intracellular calcium: the principal mediators investigated include acetylcholine and peptides of the gastrin/cholecystokinin family. Omissions? Pepsin may also cause mucosal damage during weakly acidic or non-acid gastric reflux. Pepsin /ppsn/ is an endopeptidase that breaks down proteins into smaller peptides. In the digestive tract pepsin effects only partial degradation of proteins into smaller units called peptides, which then either are absorbed from the intestine into the bloodstream or are broken down further by pancreatic enzymes. But opting out of some of these cookies may affect your browsing experience. This cookie is set by GDPR Cookie Consent plugin. But people with digestive problems, report positive results after taking such supplements. Papain cleaves IgG above the hinge region containing the disulfide bonds that join the heavy chains, but below the site of the disulfide bond between the light chain and heavy chain. Upon cellular uptake, pepsin is stored in intracellular vesicles of low pH at which its enzymatic activity would be restored. By clicking Accept All, you consent to the use of ALL the cookies. Hydrochloric acid (HCl), which is released from parietal cells in the stomach lining, activates this zymogen. The stomach is a hollow organ that is part of the gastrointestinal system, and it is responsible for functions including the formation of chyme, synthesis of proteins necessary for vitamin absorption, microbial defenses, and propagates the peristaltic reflex. Two of the population of cells in the pancreatic parenchyma make up its digestive enzymes: Pancreatic juice, composed of the secretions of both ductal and acinar cells, contains the following digestive enzymes:[2]. At pH 6.5 and above, pepsin is inactive, but it is not completely denatured or irreversibly inactivated until pH 8.0. You may also need surgery to raise your levels of pepsinogen, Help us in our mission and share this information. Pepsin in airway specimens is considered to be a sensitive and specific marker for laryngopharyngeal reflux. But some people have low levels of pepsinogen. The stomach lining contains pepsinogen, which is not active and remains inactive when it is in the stomach. How Do You Get Your Triglycerides Checked? Chief cell - Wikipedia Pepsinogen is activated by the stomach's low pH environment and inactivated by the high pH (6) in the duodenum mast cells and enterochromaffin-like cells release histamine, which acts on parietal cell H2 receptors to release hydrochloric acid. Therefore, it is most effective at a pH of approximately 1.5 to 2. Pepsinogen is the zymogen, or inactive precursor, of pepsin, the principal proteolytic enzyme of gastric juice. [12] If parietal cells are lost, mature chief cells do not form. It produces and secretes parathyroid hormone in response to low calcium levels. "Rapid Review Physiology." Its also possible that your genes may affect the amount of pepsinogen that you produce. Crude pepsin is used in the leather industry to remove hair and residual tissue from animal hides prior to their being tanned. Send comments to Richard.Bowen@colostate.edu. How do you deal with a man who is stonewalls? [16][17] At the mean pH of the laryngopharynx (pH = 6.8) pepsin would be inactive but could be reactivated upon subsequent acid reflux events resulting in damage to local tissues. Complete answer: The hydrochloric acid secreted in the stomach provides the optimum pH, which activates the pepsinogen enzyme required to digest proteins. We also use third-party cookies that help us analyze and understand how you use this website. [11][15] Therefore, pepsin in solutions of up to pH 8.0 can be reactivated upon re-acidification. It is made in an inactive form, pepsinogen, which is activated by the acidity of the stomach to self-cleave (cut itself) into a formed called the cleaved molecule. If Pepsin is not activated, then the stomach lining can become damaged. This cookie is set by GDPR Cookie Consent plugin. Cells of the stomach secrete the inactive zymogen pepsinogen, which is an enzyme that is activated by HCl. The activated enzyme then acts autocatalytically to increase the rate of formation of more pepsin. A rapid non-invasive pepsin diagnostic called Peptest is now available which determines the presence of pepsin in saliva samples. The statyl residue of pepstatin is thought to be responsible for pepstatin inhibition of pepsin; statine is a potential analog of the transition state for catalysis by pepsin and other acid proteases. Pepsin exhibits a broad cleavage specificity. [8], Gastric chief cells are epithelial cells which are found within the gastric unit or gastric gland, and form the base of the gastric unit. As a result, the stomach is the main site of synthesis and function (pH 1.5 to 2). Pepsinogen was first crystallized from the gastric mucosa of swine, and several pepsinogens have now been separated. These include the following: Pepsinogen deficiency is a rare condition. For the medication, see, "Pancreatic enzyme" and "pancrease" redirect to this discussion of endogenous forms. [5] Gastric chief cells are much longer lived and are believed to differentiate from stem cells located higher in the gastric unit in the isthmus. Digestive enzyme - Wikipedia [ pepsin + G. -gen, producing] Pepsin is a protease enzyme that is produced by the body to aid in the digestion of proteins. Pepsin is protein splitting enzyme which splits proteins into smaller chains called proteoses and peptones. Pepsinogen is activated into the digestive enzyme pepsin when it comes in contact with hydrochloric acid produced by gastric parietal cells. [2] This type of cell also secretes gastric lipase enzymes, which help digest triglycerides into free fatty acids and di- and mono-glycerides. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. Use of F(ab')2 or Fab fragments ensures that the antibodies are binding to the antigen and not Fc receptors. It can become inflamed and produce a substance called pepsinogen (PG). It is a component of gastric juice that aids in food digestion. Digestive enzymes are found in the digestive tracts of animals (including humans) and in the tracts of carnivorous plants, where they aid in the digestion of food, as well as inside cells, especially in their lysosomes, where they function to maintain cellular survival. Gastric inhibitory peptide (GIP): This peptide decreases gastric motility and is produced by duodenal mucosal cells. Pepsinogen is a powerful and abundant protein digestive enzyme secreted by the gastric chief cells as a proenzyme and then converted by gastric acid in the gastric lumen to the active enzyme pepsin. Pepsin is a chain protein (monomer) composed of two similar folding domains separated by a deep cleft. These organs along with important enzymes work together to help absorb and assimilate the food that we eat efficiently. Their production is stimulated by the presence of gastrin in the blood. To produce an F(ab')2 fragment, IgG is digested with pepsin, which cleaves the heavy chains near the hinge region. [36] PI-3 occupies the active site of pepsin using its N-terminal residues and thereby blocks substrate binding. Pepsin breaks the peptide bonds that link amino acids. Research shows that it also aids in the proper functioning of our immune system by digestive Nuclein acids. All three of these stimulate parietal cells to secrete hydrochloric acid and intrinsic factor. It is crucial for the healthy functioning of our digestive systems. [42] Pepsin was historically an additive of Beeman's gum brand chewing gum by Dr. Edwin E. Beeman. Digestive Enzymes: Types and Function - Verywell Health A proenzyme or zymogen formed and secreted by the chief cells of the gastric mucosa; the acidity of the gastric juice and pepsin itself remove 44 amino acyl residues from pepsinogen to form active pepsin. 2. This cookie is set by GDPR Cookie Consent plugin. As in many endocrine organs, with age, more oxyphil cells appear in the parathyroid gland. Gastric bypass is a type of surgery that is performed as an open operation. Its connected to your small intestine. Why Is Pepsin Secreted In An Inactive Form Pepsinogen? The fragments can be purified by gel filtration, ion exchange, or affinity chromatography. The latest research shows that the functions of Pepsin are far more elaborate than was previously thought. It is used in the leather industry to remove hair and residual tissue from hides and in the recovery of silver from discarded photographic films by digesting the gelatin layer that holds the silver. In its active form, pepsinogen is called pepsin. INTRINSIC FACTOR= secreted by parietal cells, needed for absorption of B12 in small intestine. Pepsin | Description, Production, & Function | Britannica Pepsin A [EC 3.4.23.1] is the major active form of the aspartic endopeptidase produced by and secreted in abundance as its zymogen precursor pepsinogen by the chief cells of the gastric lumen. It is formed in the chief cells of the stomach lining and is one of the most important digestive enzymes in humans and many other animals' digestive systems, where it aids in the digestion of proteins. Home | About | Contact | Copyright | Report Content | Privacy | Cookie Policy | Terms & Conditions | Sitemap. Comment * document.getElementById("comment").setAttribute( "id", "ad84d1d4a91594134eaea9f7967a5d2e" );document.getElementById("he1d94f224").setAttribute( "id", "comment" ); Save my name, email, and website in this browser for the next time I comment. Pepsin is expressed as a zymogen called pepsinogen, which has an additional 44 amino acids in its primary structure than the active enzyme. Please refer to the appropriate style manual or other sources if you have any questions. Your doctor may recommend dietary supplements if you have a low level of pepsinogen. Also, your doctor may recommend gastric bypass surgery to treat this condition, If you have a low level of pepsinogen, you may be at risk for other health conditions. Youll need to follow strict diet and exercise regimens. Schwann coined its name from the Greek word pepsis, meaning "digestion" (from peptein "to digest"). Necessary cookies are absolutely essential for the website to function properly. In biochemistry, a zymogen (/ z a m d n,-m o-/), also called a proenzyme (/ p r o n z a m /), is an inactive precursor of an enzyme.A zymogen requires a biochemical change (such as a hydrolysis reaction revealing the active site, or changing the configuration to reveal the active site) for it to become an active enzyme.The biochemical change usually occurs in Golgi . [43] One or more of the disulfide bonds that join the heavy chains in the hinge region are preserved, so the two Fab regions of the antibody remain joined together, yielding a divalent molecule (containing two antibody binding sites), hence the designation F(ab')2. In humans the concentration of pepsin in the stomach reaches 0.5 1mg/mL.[13][14]. These enzymes are synthesized and secreted predominantly by chief cells in the gastric mucosa. [10], Pepsin is most active in acidic environments between pH 1.5 to 2.5. They write new content and verify and edit content received from contributors. Trypsin: Trypsin forms when an enzyme secreted by the pancreas is activated by an enzyme in the small intestine. Pepsin was first recognized in 1836 by the German physiologist Theodor Schwann. Pepsinogens and Pepsins - Colorado State University The stomach plays a major role in digestion, both in a mechanical sense by mixing and crushing the food, and also in an enzymatic sense, by digesting it. This enzyme helps digest proteins such as those found in meat, eggs, dairy products, nuts and seeds by breaking bonds that link amino acids. [7][8][9], Some carnivorous plants, like the Heliamphora do not use digestive enzymes, but use bacteria to break down the food. The cookie is used to store the user consent for the cookies in the category "Analytics". Digestive enzymes of diverse specificities are found in the saliva secreted by the salivary glands, in the secretions of cells lining the stomach, in the pancreatic juice secreted by pancreatic exocrine cells, and in the secretions of cells lining the small and large intestines. Pepsinogen I - an overview | ScienceDirect Topics The activated enzyme then acts autocatalytically to increase the rate of formation of more pepsin. Low pH allows pepsinogen to cleave itself and form active pepsin. 4. [44], Fab and F(ab')2 antibody fragments are used in assay systems where the presence of the Fc region may cause problems. Pepsin is prepared commercially from swine stomachs. Your doctor will also perform a blood test to measure the level of pepsinogen in your body. [26] The receptor by which pepsin is endocytosed is currently unknown. Pepsinogen is a proenzyme secreted by chief cells. Unlike secretin, which is an endocrine hormone, CCK actually works via stimulation of a neuronal circuit, the end-result of which is stimulation of the acinar cells to release their content.