Effects of exogenous ghrelin on the tissue structure and somato-statin secretion in the pancreas of African ostrich chicks / Efectos de la grelina exógena en la estructura del tejido y la secreción de somato-estatinas en el páncreas de los polluelos de avestruz africanos

SUMMARY: This study aimed to investigate the effect of exogenous ghrelin on pancreatic growth and development in African ostrich chicks. Sixteen 40-day-old African ostrich chicks (male or female) were randomly divided into four groups and injected intravenously metatarsal vein with saline (control) or ghrelin (10, 50, and 100 μg/kg) for 6 days. Body and pancreas weight were determined, structural characteristics were observed using HE staining, somatostatin-immunopositive cells were detected using immunohistochemistry. The results were as follows: 1. The 50 and 100 μg/kg groups showed lower relative pancreas weight than the control group (P 0.05. Moreover, compared with the control, the islet cells in treatment groups were loosely arranged and showed reduced cytoplasm. In the exocrine pancreas, the volume of acinar cells in the 10, 50, and 100 μg/kg groups all decreased to varying degrees. 3. Somatostatin immunopositive cells were mainly located around the periphery of the islets and sporadically distributed in the center. The density of the somatostatin immunopositive cells in the 10, 50, and 100 μg/kg groups was higher than that in the control (P < 0.05). These findings suggest that exogenous ghrelin increases the area and number of islets and number of somatostatin immunopositive cells but reduces relative pancreas weight and effects the morphological and structural development of the pancreas, which may inhibit the pancreatic growth and development in African ostrich chicks.

RESUMEN: Este estudio tuvo como objetivo investigar el efecto de la grelina exógena sobre el crecimiento y desarrollo del páncreas en polluelos de avestruz africana. Dieciséis pollos de avestruz africana de 40 días (machos o hembras) se dividieron al azar en cuatro grupos y se inyectaron por vía intravenosa con solución salina (control) o grelina (10, 50 y 100 μg / kg) durante 6 días. determinadas, se observaron las características estructurales mediante tinción Hematoxilina-Eosina, se detectaron células inmunopositivas a somatostatina mediante inmunohistoquímica. Los resultados fueron los siguientes: ¨Los grupos de 50 y 100 μg / kg mostraron un menor peso relativo del páncreas que el grupo de control (P <0,05). El área de islotes por unidad de área del páncreas fue mayor en los grupos de 10, 50 y 100 μg / kg grupos que en el grupo de control (P <0,05). El número de islotes por unidad de área del páncreas fue menor en el grupo de 10 μg / kg que en el control (P <0,05). Además, en comparación con el control, las células de los islotes en los grupos de tratamiento estaban dispuestas de forma holgada y mostraban un citoplasma reducido. En el páncreas exocrino, el volumen de células acinares en los grupos de 10, 50 y 100 μg / kg disminuyó en diversos grados. Las células inmunopositivas de somatostatina se ubicaron principalmente alrededor de la periferia de los islotes y se distribuyeron esporádicamente en el centro. La densidad de las células inmunopositivas a la somatostatina en los grupos de 10, 50 y 100 μg / kg fue mayor que la del control (P <0,05). Estos hallazgos sugieren que la grelina exógena aumenta el área y el número de islotes y el número de células inmunopositivas a la somatostatina, pero reduce el peso relativo del páncreas, lo que puede inhibir el crecimiento y desarrollo pancreático en los polluelos de avestruz africana.

Desarrollo y cambios con la edad en el tubo digestivo, hígado y páncreas / Digestive tract, liver and pancreas: development and changes with age

An adequate functioning of the digestive tract, liver and pancreas is fundamental to providing the organism with the necessary conditions for its development and maintaining its digestive and systemic homeostasis. Life expectancy has increased, it is estimated that adults over 65 years old by 2050, will represent 25% of the local population. The morphological and functional changes associated with aging in the digestive system, liver and pancreas are modest except for those that occur in the microbiota. Recently it has been possible to establish the contribution of the microbiota to life expectancy and establish a link between gastrointestinal microbiota, inflammation associated with aging (inflammaging) and survival. This represents a shift in the paradigm of our understanding physiology, chronic diseases, neoplasms and for the development of new therapies.

Un adecuado funcionamiento del tubo digestivo, hígado y páncreas es fundamental para poder brindar al organismo las condiciones necesarias para su desarrollo y mantener su homeostasis digestiva y sistémica. La expectativa de vida se ha incrementado, estimándose a nivel nacional que para el año 2050 los adultos mayores de 65 años representarán el 25% de la población. Los cambios morfológicos y funcionales asociados al envejecimiento en el aparato digestivo, hígado y páncreas son modestos a excepción, de los que se producen en la microbiota. Recientemente se ha podido establecer la contribución de la microbiota a la esperanza de vida y establecer un nexo entre microbiota gastrointestinal, inflamación asociada al envejecimiento y sobrevida. Esto representa un cambio en el paradigma sobre cómo comprendemos la fisiología, las patologías crónicas, neoplásicas y en el desarrollo de nuevas terapias.

developmental gross morphology of pancreas in chick embryo after prenatal administration of valproic acid

To determine the effects of prenatal administration of valproic acid on the developmental gross morphology of pancreas in chick embryo. Experimental study. Anatomy Department, Regional Centre, College of Physicians and Surgeons, Islamabad, from February 2010 to February 2011. An experimental group-A and control group-B, comprised of 30 eggs each. Freshly laid fertilized chicken eggs of experimental group were injected with valproic acid, incubated and hatched. Eggs of control group underwent sham treatment using normal saline. The chicks were sacrificed on hatching or day 22 of incubation, whichever was earlier. The pancreata of only alive chicks of both groups were dissected out, and evaluated for gross morphology in terms of length and weight by statistically comparing with control ones. Then pancreata were stained with aldehyde fuchsin and orange-G stain to study other obvious histological effects, if any. Chicken embryos exposed to valproic acid in ovo, showed significant decrease in length and weight of pancreata. The mean of length [cm] of pancreata in group-A was 2.208 +/- 0.166, and group-B was 2.300 +/- 0.102 [p=0.008]. The mean of weight [g] of pancreata in group-A was 0.032 +/- 0.009, and group-B was 0.048 +/- 0.005 [p=0.001]. Valproic acid exposure showed retarding effect on the gross development of pancreas as depicted by decrease in the length and weight of pancreata

Comparative effect of cane syrup and natural honey on abdominal viscera of growing male and female rats.

The high intake of refined sugars, mainly fructose has been implicated in the epidemiology of metabolic diseases in adults and children. With an aim to determine whether honey can substitute refined sugars without adverse effect, the long-term effects of natural honey and cane syrup have been compared on visceral morphology in growing rats fed from neonatal age. Honey increased the caecum and pancreas weights in male rats, which could enhance enzymatic activities of pancreas and digestive functions by intestinal microflora of caecum. Unlike honey, cane syrup caused fatty degenerations in the liver of both male and female rats. Honey enhanced intestinal villi growth, and did not cause pathology in the rodents’ abdominal viscera, suggesting potential nutritional benefit as substitution for refined sugars in animal feed.

Effects of all-trans retinoic acid on the pancreas development in rat Embryo

Recent data shows that retinoic acid [RA] signaling is required for early pancreatic development in animals, whereas the effects of exogenous All-trans Retinoic Acid [ATRA] on gestation day [GD] 10 in later development have not been well documented. In this experimental interventional study, female rats, were randomly divided into two groups [experimental and control, n=5 each]. Animals in the experimental group received single dose [100 mg /kg] of ATRA orally on GD 10 and fetuses were observed on GD 18.The fetus pancreas [from both the experimental and control groups; each n=24] were processed for staining and followed by measuring the accumulation of pancreatic acinus and pancreatic ductile associated with the islets of langerhans. In addition, the mean diameter of pancreatic acinus, acinar cells and related nucleus were measured. Statistical analysis was done by student t-test, P value<0.05 being considered significant. In the experimental embryos on GD 18, the mean accumulation of pancreatic acinus [23.5%], and pancreatic ductile, associated with the islets of langerhans [76%] per field were increased. There was a significant difference in accumulation of pancreatic acinus [P< 0.0001] and pancreatic ductile, associated with the islets of langerhans [P< 0.0001], between the groups in this regard. The mean diameter of pancreatic acinus and the related nucleus were compared in the two groups, and results showed significant [P< 0.0001] decrease of this parameter in the experimental group. Results suggest that ATRA may have positive effects on proliferation, differentiation and maturation of pancreatic acinus and pancreatic ductile associated with the islets of langerhans

Histomorphometrical study on pancreas in pre- and postnatal Mehraban male sheep

In the present study, different structures of the stroma and parenchyma of pancreas in Mehraban breed of male sheep were histomorphometrically studied. Animals were collected from different age groups including fetus, neonate, young and old adults. In each group, 3 animals and total of 12 animals were used. Histomorphometric studies consisted of the determination of volume density of stromal and parenchyma! structures and the percentages of islet cells in different age groups. The results indicated that volume density of endocrine portion and connective tissue elements of pancreas between fetus and neonate and also between neonate and adult were significantly different. There was an apparent significant difference in volume density of blood vessels between neonate and old adult. A significant difference was also seen in volume density of ducts in the right lobe of neonate pancreas compared to the left lobe and body of pancreas, but no significant differences were seen in the other age groups. There was a significant difference in the mean number of beta cells in old adult compared to others, which indicated that this endocrine cell increased at this age. The percentages of endocrine cells varied in different age groups, but the predominant cell type of islets was beta and then alpha cells. There was low number of delta cells. The highest percentages of beta, alpha and delta cells were found in neonate, young adult and fetus, respectively. The lowest percentages of these cells were observed in fetus, [neonate] and neonate, respectively

Growth of the mouse pancreas during postnatal development

The postnatal growth of the mouse pancreas was studied using stereological methods. The measurements obtained included gland mass, total cell number, the number and frequency of cells in each morphological comportment and the nuclear and cytoplasmic volume of the acinar cells. Pancreatic mass increased significantly (>10,000 fold) in the first 70 days of life and this was accompanied by an increase of 6,841 per cent, 7,027 per cent, 4,864 per cent and 3,360 per cent, respectively. During the same period, the mean acinar cell volume increased by only 146 per cent. These results showed that growth of the mouse pancreas during postnatal development, occurred through intense profiferative activity of all cell types and by an increase in the size of individual cells, notably the acinar cells.

Is pancreas development abnormal in the non-obese diabetic mouse, a spontaneous model of type I diabetes?

Despite extensive genetic and immunological research, the complex etiology and pathogenesis of type I diabetes remains unresolved. During the last few years, our attention has been focused on factors such as abnormalities of islet function and/or microenvironment, that could interact with immune partners in the spontaneous model of the disease, the non-obese diabetic (NOD) mouse. Intriguingly, the first anomalies that we noted in NOD mice, compared to control strains, are already present at birth and consist of 1) higher numbers of paradoxically hyperactive ß cells, assessed by in situ preproinsulin II expression; 2) high percentages of immature islets, representing islet neogenesis related to neonatal BETA-cell hyperactivity and suggestive of in utero BETA-cell stimulation; 3) elevated levels of some types of antigen-presenting cells and FasL+ cells, and 4) abnormalities of extracellular matrix (ECM) protein expression. However, the colocalization in all control mouse strains studied of fibroblast-like cells (anti-TR-7 labeling), some ECM proteins (particularly, fibronectin and collagen I), antigen-presenting cells and a few FasL+ cells at the periphery of islets undergoing neogenesis suggests that remodeling phenomena that normally take place during postnatal pancreas development could be disturbed in NOD mice. These data show that from birth onwards there is an intricate relationship between endocrine and immune events in the NOD mouse. They also suggest that tissue-specific autoimmune reactions could arise from developmental phenomena taking place during fetal life in which ECM-immune cell interaction(s) may play a key role

Terapia gênica para o diabetes / Gene Therapy for the Diabetes

A administraçäo de insulina exógena tem sido a única forma de tratamento disponível para milhöes de indivíduos portadores de diabetes mellitus do tipo 1 (insulino-dependente). Embora o transplante de pâncreas tenha sido empregado com sucesso para um número limitado de pacientes, ele ainda é considerado um procedimento invasivo com alto risco de complicaçöes. Por outro lado, estudos preliminares onde o transplante de ilhotas pancreáticas foi realizado sem o emprego de glucocorticóides no esquema de imunossupressäo demonstraram resultados Extremamente promissores. Entretanto, o emprego de ilhotas pancreáticas, assim como o transplante de pâncreas, enfrenta o problema da escassez de órgäos disponíveis para transplante. Assim, um dos grandes objetivos da terapia gênica para diabetes é a geraçäo de fontes limitadas de células que apresemtem secreçäo normal de insulina em resposta ao estímulo da glicose, capazes de serem transplantadas sem a necesidade de imunossupressäo sistêmica. Este artigo tem como finalidade revisar como a terapia gênica pode ser empregada na obtençäo desta fonte de células, assim como discutir os últimos avanços no campo da biologia celular e molecular em relaçäo ao crescimento e diferenciaçäo da célula Beta.

study of histochemical and histological structure on the pancreas of albino rat

In the present study, the postanatal developmend, microvascular and innervation of both indocrine and exocrine parts of the pancreas was done on 180 albino rats of Spargue-Dawley strain of both sexes. 30 animals were adults [60 days-old] while the remaining 150 animals were divided into five groups each consisted of 30 animals of 1, 7, 14, 21 and 28 days old respectively, and it was observed that: * Exocrine part of the pancreas had different rate of growth than the endocrine part, it was found that in the first 7 days of life the endocrine tissue grows faster than the exocrine tissue, then after that age the exocrine tissues strated to grow rapildy with rate more than that of the endocrine tissues up of age of 28 days, after this age onwards both endocrine and exocrine parts showe constant and slow rate of growth. * The body weight and pancreatic weight were found to increase with increasing age, the rate of growth was rapid during the first week after birth with more increase in body weight than pancreatic weight, after 28 days the rate of growth of both body and pancreas was more slower and both increased nearly propartionally. * The total number of islets per pancreas was found to increase with increasing age up to adulthood, the rate of increase was rapid in the first 28 days of life then became slower after that age. * In one day old rats, it was found the presence of distinct blood supply for exocrine part of the pancreas as well as the endocrine part, small and few glomerular like swellings and insulo-acinar capillaries were detected in this age group. The insular capillaries appear to have the same caliber as that of the acinar capillaries with increasing age of the animal all blood vessels of the pacnreas including intrlobular arteris, intralobular arteries as well as insular and acinar capillaries appeared to increase in size. Also the size and frequency of intra-insular capillaries, glomerular like swellings and insulo-acinar portal vessels were increased with increasing age up to adulthood. * True and pseudocholinesterase positive interlobular nerve trunks were observed to divide repeatedly forming the intrapancreatic nerve plexues [peri-acinar, peri-insular, intrainsular, periductal and peri-vascular nerve plexuses]. All these intrapancreatic nerve plexuses were oberved from the the first week birth up to adulthood, while only scattered nerve fibers without forming nerve plexuses were noticed at one day after birth. * True and pseudocholinesterase positive intrapanceratic genglia and nerve cells were found mostly in the interlobular connective tissue septa, however some ganglia were observed among the aini, adjacent to the main pancreatic ducts and blood vessels and less commonly adjacent to islets of langehans. Succinic dehydrogenase enzyme activity was observed throught the pancreas, the exocrine part had higher enzyme reaction than that of the islets of Langerhans moreover the beta-cells showed higher enzyme activity than the cells of the periphery of the islet [A-cell region] and some A-cells possessed low or no enzyme activity at all. Connective tissue cells had low enzyme activity. The intensity of succinic dehydrogenase enzyme reaction was observed to increase with advanced age throughout the whole pancrease

Estudo morfológico e estereológico do desenvolvimento pós-natal do pâncreas da cobaia (Cavia porcellus) / Morphological and stereological study of the posnatal development of guinea pig pancreas (Cavia porcellus)

O desenvolvimento pós-natal do pâncreas da cobaia (Cavia porcellus) foi estudado por métodos estereológicos ao microscópio de luz, no período de 2 a 140 dias de idade. As modificaçöes morfométricas detectadas no estudo dos dados numéricos foram acompanhadas por uma análise morfológica qualitativa. A massa pancreática exibiu um aumento acentuado de 805 por cento, no período de 2 a 140 dias de vida pós-natal. Este crescimento pode ser expresso pela equaçäo linear Y = 519,2 + 14,2x (coeficiente de correlaçäo r= 0,95) e o tempo de duplicaçäo calculado por essa equaçäo foi de 38,6 dias. Este crescimento de massa pancreática ocorreu devido ao aumento de volume em todos os compartimentos morfológicos, notadamente o dos ácinos e o das outras estruturas (estroma). A relativa estabilidade da densidade de volume dos vários compartimentos mostrou que durante este crescimento as relaçöes volumétricas säo mantidas. O volume do compartimento dos ácinos aumentou 756 por cento, no período total analisado. Este crescimento pode ser representado pela equaçäo Y = 204,1 + 4,7x (r= 0,92) e o tempo de duplicaçäo calculado para o período de 2 a 140 dias foi de 45,6 dias. Este aumento de volume do compartimento dos ácinos ocorreu por dois mecanismos de crescimento: a atividade proliferativa e o aumento de volume celular. O estudo da evoluçäo do número absoluto de células acinosas mostrou um aumento de 361 por cento, no período de 2 a 140 dias. A equaçäo obtida pela análise de regressäo para exprimir esse aumento foi Y = 110,1 + 1,6x (r=0,94) e o tempo de duplicaçäo calculado foi de 70,8 dias. Por outro lado, o volume celular médio das células acinosas aumentou 210 por cento, no mesmo período. A equaçäo linear obtida foi Y = 755,3 + 6,4x (r=0,86) e o tempo de duplicaçäo foi de 120,0 dias. Os dados mostraram que no período total de 2 a 140 dias, o aumento de volume do compartimento dos ácinos ocorreu com um predomínio de atividade proliferativa sobre aumento de volume celular