Effect of exogenous insulin and glucagon on exocrine pancreatic secretion in rats in vivo

Causes of Exocrine Pancreatic Insufficiency Other Than Chronic Pancreatitis

Exocrine pancreatic insufficiency (EPI), an important cause of maldigestion and malnutrition, results from primary pancreatic disease or is secondary to impaired exocrine pancreatic function. Although chronic pancreatitis is the most common cause of EPI, several additional causes exist. These include pancreatic tumors, pancreatic resection procedures, and cystic fibrosis. Other diseases and conditions, such as diabetes mellitus, celiac disease, inflammatory bowel disease, and advanced patient age, have also been shown to be associated with EPI, but the exact etiology of EPI has not been clearly elucidated in these cases. The causes of EPI can be divided into loss of pancreatic parenchyma, inhibition or inactivation of pancreatic secretion, and postcibal pancreatic asynchrony. Pancreatic enzyme replacement therapy (PERT) is indicated for the conditions described above presenting with clinically clear steatorrhea, weight loss, or symptoms related to maldigestion and malabsorption. This review summarizes the current literature concerning those etiologies of EPI less common than chronic pancreatitis, the pathophysiology of the mechanisms of EPI associated with each diagnosis, and treatment recommendations.

Mechanisms of Post-Pancreatitis Diabetes Mellitus and Cystic Fibrosis-Related Diabetes: A Review of Preclinical Studies

Anatomical proximity and functional correlations between the exocrine and endocrine pancreas warrant reciprocal effects between the two parts. Inflammatory diseases of the exocrine pancreas, such as acute or chronic pancreatitis, or the presence of cystic fibrosis disrupt endocrine function, resulting in diabetes of the exocrine pancreas. Although novel mechanisms are being increasingly identified, the intra- and intercellular pathways regulating exocrine-endocrine interactions are still not fully understood, making the development of new and more effective therapies difficult. Therefore, this review sought to accumulate current knowledge regarding the pathogenesis of diabetes in acute and chronic pancreatitis, as well as cystic fibrosis.

[Hypoglycemia in neonates: a review of the literature and a case report]

Hypoglycemia in the neonatal period is one of the urgent problems of pediatric endocrinology. The main factors that lead to disruption of carbohydrate homeostasis are generally known, but the issues of neonatal hypoglycemia continue to be actively studied. In the last few years, the effect of low blood glucose on brain neurons has been studied, the issues of glycemia monitoring in the first days of life have been outlined, and strategies for managing newborns with hypoglycemic syndrome are being discussed.

The level of bile salt-stimulated lipase in the milk of Chinese women and its association with maternal BMI

This study aimed to investigate the bile salt-stimulated lipase (BSSL) concentration in the milk of Chinese women and its correlation with maternal body mass index (BMI), gestational diabetes mellitus (GDM) and gestational hypertensive disorder (GHD). The BSSL levels in the milk samples were measured by enzyme-linked immunosorbent assay (ELISA). BSSL level in colostrum milk of mothers with full-term infants was positively correlated with pregnancy week and negatively correlated with maternal pre-pregnancy BMI and BMI late in pregnancy. Moreover, the BSSL concentration in mature milk was positively correlated with BMI gain during pregnancy. The BSSL concentration in colostrum milk was lower in GDM mothers than in normal mothers. The BSSL helps infants digest fat in early life and its level was associated with lactation. The changes in BSSL characteristics with maternal BMI and GDM in this study may have clinical implications regarding the effects of pregnancy weight and metabolism on the nutrition and health of the offspring.

Which factors determine exocrine pancreatic dysfunction in diabetes mellitus?

The exocrine structure is significantly affected by diabetes because of endocrine structure-function disorder within the pancreas. Exocrine pancreatic dysfunction (EPD) is the general name of the malabsorption process resulting from inadequate production, release, decreased activation, and/or insufficient degradation of enzymes required for digestion from pancreatic acinar cells. It is important to diagnose patients early and correctly, since there may be both macro- and micro-nutrient deficiency in EPD. In this paper, EPD, the diabetes-EPD relationship, and the predictive, effective factors affecting the emergence of EPD are briefly explained and summarized with contemporary literature and our experienced based on clinical, lab, and radiological findings.

[Enteral failure and metabolic syndrome: Common neurohormonal mechanisms of development, possibilities of their rational therapy]

The paper deals with small bowel (SB) functional disorders in metabolic syndrome (MS). The main components of a cascade of metabolic abnormalities in MS are closely due to SB functional changes. This is associated to some extent with the presence of common neurohormonal mechanisms in the development of enteropathy and MS. The paper gives the physical, laboratory and instrumental methods for identifying SB dysfunctions in patients with MS. Therapy for the latter is of particular interest in the context of SB functional recovery. The authors discuss the possibilities of enteropathy therapy in patients with MS; thus there is not only SB functional recovery, but also improved overall metabolic processes.

Less common etiologies of exocrine pancreatic insufficiency

Exocrine pancreatic insufficiency (EPI), an important cause of maldigestion and malabsorption, results from primary pancreatic diseases or secondarily impaired exocrine pancreatic function. Besides cystic fibrosis and chronic pancreatitis, the most common etiologies of EPI, other causes of EPI include unresectable pancreatic cancer, metabolic diseases (diabetes); impaired hormonal stimulation of exocrine pancreatic secretion by cholecystokinin (CCK); celiac or inflammatory bowel disease (IBD) due to loss of intestinal brush border proteins; and gastrointestinal surgery (asynchrony between motor and secretory functions, impaired enteropancreatic feedback, and inadequate mixing of pancreatic secretions with food). This paper reviews such conditions that have less straightforward associations with EPI and examines the role of pancreatic enzyme replacement therapy (PERT). Relevant literature was identified by database searches. Most patients with inoperable pancreatic cancer develop EPI (66%-92%). EPI occurs in patients with type 1 (26%-57%) or type 2 diabetes (20%-36%) and is typically mild to moderate; by definition, all patients with type 3c (pancreatogenic) diabetes have EPI. EPI occurs in untreated celiac disease (4%-80%), but typically resolves on a gluten-free diet. EPI manifests in patients with IBD (14%-74%) and up to 100% of gastrointestinal surgery patients (47%-100%; dependent on surgical site). With the paucity of published studies on PERT use for these conditions, recommendations for or against PERT use remain ambiguous. The authors conclude that there is an urgent need to conduct robust clinical studies to understand the validity and nature of associations between EPI and medical conditions beyond those with proven mechanisms, and examine the potential role for PERT.

The islet-acinar axis of the pancreas: more than just insulin

Although the role of the islets in the regulation of acinar cell function seemed a mystery to investigators who observed their dispersion among pancreatic acini, over time an appreciation for this intricate and unique structural arrangement has developed. The last three decades have witnessed a steadily growing understanding of the interrelationship of the endocrine and the exocrine pancreas. The islet innervation and vascular anatomy have been more fully characterized and provide an appropriate background for our current understanding. The interrelationship between the endocrine and exocrine pancreas is mediated by islet-derived hormones such as insulin and somatostatin, other humoral factors including pancreastatin and ghrelin, and also neurotransmitters (nitric oxide, peptide YY, substance P, and galanin) released by the nerves innervating the pancreas. Although considerable progress has been achieved, further work is required to fully delineate the complex interplay of the numerous mechanisms involved. This review aims to provide a comprehensive update of the current literature available, bringing together data gleaned from studies addressing the actions of individual hormones, humoral factors, and neurotransmitters on the regulation of amylase secretion from the acinar cell. This comprehensive view of the islet-acinar axis of the pancreas while acknowledging the dominant role played by insulin and somatostatin on exocrine secretion sheds light on the influence of the various neuropeptides on amylase secretion.

Role of endogenous insulin in pancreatic secretion in rats

BACKGROUND

Pancreatic exocrine tissue is influenced by islet hormones through the islet-acinar portal system. We investigated the role of endogenous insulin in pancreatic secretion in vivo in rats.

METHODS

Anesthetized rats were prepared by cannulation of the pancreatic duct, and pure pancreatic juice was collected. Pancreatic secretion was stimulated by intravenous infusion of cholecystokinin (CCK) (0.06 microgram/kg/h) with or without intravenous infusion of glucose (0.25 and 0.5 g/kg/h). The effect of intravenous infusion of glucose (0.5 g/kg/h) on pancreatic secretion stimulated by intraduodenal infusion of casein (400 mg/h) was also studied.

RESULTS

Intravenous infusion of glucose (0.5 g/kg/h) produced a significant elevation of plasma insulin and glucose levels. The basal pancreatic secretion was not influenced by glucose. Pancreatic secretion of juice volume, amylase, and trypsin in response to stimulation by CCK was significantly augmented by glucose (0.5 g/kg/h). Intravenous infusion of glucose also resulted in significant increases in casein-stimulated pancreatic juice volume, amylase and trypsin outputs.

CONCLUSION

Endogenously released insulin plays an important role in potentiating pancreatic secretion stimulated by exogenous CCK and intraduodenal infusion of casein.