scholarly journals The ontogeny of the endocrine pancreas in the fetal/newborn baboon

2012 ◽  
Vol 214 (3) ◽  
pp. 289-299 ◽  
Author(s):  
Amy R Quinn ◽  
Cynthia L Blanco ◽  
Carla Perego ◽  
Giovanna Finzi ◽  
Stefano La Rosa ◽  
...  

Erratic regulation of glucose metabolism including hyperglycemia is a common condition in premature infants and is associated with increased morbidity and mortality. The objective of this study was to examine histological and ultrastructural differences in the endocrine pancreas in fetal (throughout gestation) and neonatal baboons. Twelve fetal baboons were delivered at 125 days (d) gestational age (GA), 140d GA, or 175d GA. Eight animals were delivered at term (185d GA); half were fed for 5 days. Seventy-three nondiabetic adult baboons were used for comparison. Pancreatic tissue was studied using light microscopy, confocal imaging, and electron microscopy. The fetal and neonatal endocrine pancreas islet architecture became more organized as GA advanced. The percent areas of α-β-δ-cell type were similar within each fetal and newborn GA (NS) but were higher than the adults (P<0.05) regardless of GA. The ratio of β cells within the islet (whole and core) increased with gestation (P<0.01). Neonatal baboons, which survived for 5 days (feeding), had a 2.5-fold increase in pancreas weight compared with their counterparts killed at birth (P=0.01). Endocrine cells were also found in exocrine ductal and acinar cells in 125, 140 and 175d GA fetuses. Subpopulation of tissue that coexpressed trypsin and glucagon/insulin shows the presence of cells with mixed endo–exocrine lineage in fetuses. In summary, the fetal endocrine pancreas has no prevalence of a α-β-δ-cell type with larger endocrine cell percent areas than adults. Cells with mixed endocrine/exocrine phenotype occur during fetal development. Developmental differences may play a role in glucose homeostasis during the neonatal period and may have long-term implications.

1989 ◽  
Vol 26 (1) ◽  
pp. 40-46 ◽  
Author(s):  
H. Furuoka ◽  
T. Shirakawa ◽  
H. Taniyama ◽  
H. Ohishi ◽  
H. Satoh ◽  
...  

Pancreatic tissue from 20 horses was examined using immunocytochemical techniques. In aged horses, neogenesis of endocrine cells, neoformation, and hyperplasia of islets occurred closely associated with the pancreatic duct; these changes were regarded as nesidioblastosis. In addition, pancreatic fibrosis accompanied by ductal proliferation and endocrine neogenesis was considered a regenerative change. Thus, the origin of neoformation in the endocrine pancreas was in the ductal system, and it is suggested that the pancreatic endocrine cells were of endodermal origin.


Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1799
Author(s):  
Jujhar Atwal ◽  
Jonathan Stockman ◽  
Matthew Gilham ◽  
David Allaway ◽  
Helen Renfrew ◽  
...  

The implications of long-term high calcium (Ca) intake are well documented in growing dogs and in adult dogs of large breed size, however, the consequences on other breeds and breed sizes are yet to be determined. Eighteen neutered adult beagles, nine males and nine females aged 1.4–4.4 years, were randomized to control or test diets providing in g∙4184 kJ−1 (1000 kcal−1): 1.44 and 7.19 total Ca balanced with 1.05 and 4.25 total phosphorus, respectively, for 40 weeks. Health parameters, ultrasound scans, radiographs, glomerular filtration rate, and mineral balance were measured at eight-week intervals. All dogs remained healthy with no measured evidence of orthopedic, urinary, or renal disease. The test diet resulted in a 5.2 fold increase in fecal Ca excretion. Apparent Ca digestibility (%) and Ca balance (g/d) did not significantly (p > 0.05) change from baseline in the test diet group, although dogs displayed a positive Ca balance (maximum at week 8, 1.11 g/d with 95% CI (0.41, 1.80)) before a neutral Ca balance was restored at week 32. Despite an initial positive Ca balance, we can conclude that no measurable adverse health effects were observed as a result of the test diet fed in this study in beagles over a period of 40 weeks.


1997 ◽  
Vol 82 (3) ◽  
pp. 943-948
Author(s):  
Jian Tu ◽  
Bernard E. Tuch

Abstract Glucokinase (GK) is the glucose sensor in the adult β-cell, resulting in fuel for insulin synthesis and secretion. Defects in this enzyme in the β-cell are responsible for the genetic disorder maturity-onset diabetes of the young, with the β-cell being unable to secrete insulin appropriately when challenged with glucose. The human fetalβ -cell is also unable to secrete insulin when exposed to glucose, but whether GK is present and functional in this developing cell is unknown. To determine the expression of GK in human fetal pancreatic tissue, cytosolic protein was extracted from human fetal islet-like cell clusters (ICCs) at 17–19 weeks gestation and examined for protein content and enzyme activity. On Western blots, a single band corresponding to GK was seen at 52 kDa, and this was similar to that obtained from human adult islets. The maximal velocity (Vmax) of GK was less in fetal ICCs than that in adult islets (8.7 vs. 20.7 nmol/mg protein·h); similar Km values were found in both ICCs and islets. No attempt was made to determine which cells in an ICC contained GK. Glucose utilization was determined radiometrically; the Vmax of the high Km component was less in ICCs than in islets (31.3 pmol/ICC·h vs. 101.4 pmol/islet·h). Culture of ICCs for 3–7 days in medium containing 11.2 mmol/L glucose resulted in a 3.7-fold increase in the Vmax of GK and a 1.8-fold increase in glucose utilization. These enhanced activities of glucose phosphorylation and glycolysis, however, did not lead to the β-cell being able to secrete insulin when exposed to glucose. In conclusion, glucokinase is present and functional in human fetal ICCs, but the inability of the human fetal β-cell to secrete insulin in response to an acute glucose challenge is not due to immaturity of this enzyme.


Neurology ◽  
2021 ◽  
Vol 96 (12) ◽  
pp. e1620-e1631
Author(s):  
James B. Wetmore ◽  
Yi Peng ◽  
Heng Yan ◽  
Suying Li ◽  
Muna Irfan ◽  
...  

ObjectiveTo determine the association of dementia-related psychosis (DRP) with death and use of long-term care (LTC); we hypothesized that DRP would be associated with increased risk of death and use of LTC in patients with dementia.MethodsA retrospective cohort study was performed. Medicare claims from 2008 to 2016 were used to define cohorts of patients with dementia and DRP. Outcomes were LTC, defined as nursing home stays of >100 consecutive days, and death. Patients with DRP were directly matched to patients with dementia without psychosis by age, sex, race, number of comorbid conditions, and dementia index year. Association of DRP with outcomes was evaluated using a Cox proportional hazard regression model.ResultsWe identified 256,408 patients with dementia. Within 2 years after the dementia index date, 13.9% of patients developed DRP and 31.9% had died. Corresponding estimates at 5 years were 25.5% and 64.0%. Mean age differed little between those who developed DRP (83.8 ± 7.9 years) and those who did not (83.1 ± 8.7 years). Patients with DRP were slightly more likely to be female (71.0% vs 68.3%) and white (85.7% vs 82.0%). Within 2 years of developing DRP, 16.1% entered LTC and 52.0% died; corresponding percentages for patients without DRP were 8.4% and 30.0%, respectively. In the matched cohort, DRP was associated with greater risk of LTC (hazard ratio [HR] 2.36, 2.29–2.44) and death (HR 2.06, 2.02–2.10).ConclusionsDRP was associated with a more than doubling in the risk of death and a nearly 2.5-fold increase in risk of the need for LTC.


Development ◽  
1987 ◽  
Vol 100 (4) ◽  
pp. 661-671 ◽  
Author(s):  
B. Kramer ◽  
A. Andrew ◽  
B.B. Rawdon ◽  
P. Becker

To determine whether mesenchyme plays a part in the differentiation of gut endocrine cells, proventricular endoderm from 4- to 5-day chick or quail embryos was associated with mesenchyme from the dorsal pancreatic bud of chick embryos of the same age. The combinations were grown on the chorioallantoic membranes of host chick embryos until they reached a total incubation age of 21 days. Proventricular or pancreatic endoderm of the appropriate age and species reassociated with its own mesenchyme provided the controls. Morphogenesis in the experimental grafts corresponded closely to that in proventricular controls, i.e. the pancreatic mesenchyme supported the development of proventricular glands from proventricular endoderm. Insulin, glucagon and somatostatin cells and cells with pancreatic polypeptide-like immunoreactivity differentiated in the pancreatic controls. The latter three endocrine cell types, together with neurotensin and bombesin/gastrin-releasing polypeptide (GRP) cells, developed in proventricular controls and experimental grafts. The proportions of the major types common to proventriculus and pancreas (somatostatin and glucagon cells) were in general similar when experimental grafts were compared with proventricular controls but different when experimental and pancreatic control grafts were compared. Hence pancreatic mesenchyme did not materially affect the proportions of these three cell types in experimental grafts, induced no specific pancreatic (insulin) cell type and allowed the differentiation of the characteristic proventricular endocrine cell types, neurotensin and bombesin/GRP cells. However, an important finding was a significant reduction in the proportion of bombesin/GRP cells, attributable in part to a decrease in their number and in part to an increase in the numbers of endocrine cells of the other types. This indicates that mesenchyme may well play a part in determining the regional specificity of populations of gut endocrine cells.


2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Priscila Y Sato ◽  
J K Chuprun ◽  
Jessica Ibetti ◽  
John W Elrod ◽  
Walter J Koch

β-adrenergic receptors (βARs) are powerful regulators of cardiovascular function and are impaired in heart failure (HF). Signal transduction of βARs is canonically shut down by phosphorylation via G protein-coupled receptor kinase 2 (GRK2) and the subsequent binding of β-arrestins. This process of receptor desensitization is enhanced in HF via the up-regulation of GRK2 and contributes to disease progression. We have recently reported non-canonical actions of GRK2, which contribute to the development of HF independent of βAR desensitization. We have previously shown that GRK2 can act as a pro-death kinase in cardiomyocytes bytranslocating to mitochondria and activating mitochondria permeability transition. This study was designed to gain more understanding of the mitochondrial function of GRK2. We isolated adult cardiomyocytes from cardiac-specific transgenic mice overexpressing GRK2 at levels found in human HF (TgGRK2), and examined superoxide production using the redox sensitive reporter MitoSox Red. Confocal imaging revealed a 4.6 fold increase in superoxide levels in cardiomyocytes overexpressing Grk2 as compared to non-transgenic (NLC) cardiomyocytes (corrected total cell fluorescence 11.59±1.06, TgGRK2 (n= 3 hearts, 88 cells) vs 2.54±0.02 NLC (n=3 hearts, 52 cells), (p<0.001). This indicates that the chronic elevation of GRK2 induces mitochondrial oxidative stress priming the myocyte for enhanced injury. To further explore the mitochondrial actions of GRK2 and consequences of redox stress we examined oxidative phosphorylation by performing oxygen consumption measurements in neonatal rat ventricular myocytes overexpressing GRK2 or GFP-expressing control myocytes. Seahorse analysis showed that cells overexpressing GRK2 have a significant decrease in spare respiratory capacity indicating that cells with elevated GRK2 levels have an impaired capacity to generated ATP during times of stress. Further studies with mutants that limit GRK2 kinase activity or mitochondrial localization demonstrate that mitochondrial GRK2 may be a significant contributor to cellular dysfunction as seen in heart failure.


2005 ◽  
Vol 12 (4) ◽  
pp. 327-332 ◽  
Author(s):  
Kazuya Edamura ◽  
Koko Nasu ◽  
Yukiko Iwami ◽  
Ryohei Nishimura ◽  
Hiroyuki Ogawa ◽  
...  

1990 ◽  
Vol 259 (6) ◽  
pp. L415-L425 ◽  
Author(s):  
P. E. Roberts ◽  
D. M. Phillips ◽  
J. P. Mather

A novel epithelial cell from normal neonatal rat lung has been isolated, established, and maintained for multiple passages in the absence of serum, without undergoing crisis or senescence. By careful manipulation of the nutrition/hormonal microenvironment, we have been able to select, from a heterogeneous population, a single epithelial cell type that can maintain highly differentiated features in vitro. This cell type has characteristics of bronchiolar epithelial cells. A clonal line, RL-65, has been selected and observed for greater than 2 yr in continuous culture. It has been characterized by ultrastructural, morphological, and biochemical criteria. The basal medium for this cell line is Ham's F12/Dulbecco's modified Eagle's (DME) medium plus insulin (1 micrograms/ml), human transferrin (10 micrograms/ml), ethanolamine (10(-4) M), phosphoethanolamine (10(-4) M), selenium (2.5 x 10(-8) M), hydrocortisone (2.5 x 10(-7) M), and forskolin (5 microM). The addition of 150 micrograms/ml of bovine pituitary extract to the defined basal medium stimulates a greater than 10-fold increase in cell number and a 50- to 100-fold increase in thymidine incorporation. The addition of retinoic acid results in further enhancement of cell growth and complete inhibition of keratinization. We have demonstrated a strategy that may be applicable to isolating other cell types from the lung and maintaining their differentiated characteristics for long-term culture in vitro. Such a culture system promises to be a useful model in which to study cellular events associated with differentiation and proliferation in the lung and to better understand the molecular mechanisms involved in these events.


Sign in / Sign up

Export Citation Format

Share Document