Ethanol-Induced Dissociation Between Whole Pancreatic Blood Flow and Islet Blood Flow in the Rat

1988 ◽  
Vol 20 (05) ◽  
pp. 311-312 ◽  
Author(s):  
L. Jansson ◽  
B. Petersson
Keyword(s):  
Blood Flow ◽  
Pancreatic Blood Flow ◽  
Islet Blood Flow

Pancreatic islet blood flow in conscious rats during hyperglycemia and hypoglycemia

2001 ◽  
Vol 280 (6) ◽  
pp. R1601-R1605 ◽  
Author(s):  
M. Iwase ◽  
K. Tashiro ◽  
Y. Uchizono ◽  
D. Goto ◽  
M. Yoshinari
Keyword(s):  
Blood Flow ◽  
Pancreatic Islet ◽  
Organ Perfusion ◽  
Pancreatic Blood Flow ◽  
Pentobarbital Sodium ◽  
Time Points ◽  
Conscious Rats ◽  
Colored Microspheres ◽  
Islet Blood Flow ◽  
Anesthetized Rats

Anesthesia affects general hemodynamics and regulation of organ perfusion. We used colored microspheres to measure pancreatic islet blood flow in conscious rats at two time points, during either hyperglycemia or hypoglycemia. This method, using black and green microspheres, was validated by comparison with previous microsphere experiments and by lack of effect of a nonmetabolizable glucose analog, 3- O-methylglucose, on islet perfusion. Basal and glucose-stimulated islet blood flow levels were similar in pentobarbital sodium-anesthetized and conscious rats. However, the basal distribution of pancreatic blood flow was altered by anesthesia (fractional islet blood flow 5.8 ± 0.4% in conscious rats, 7.9 ± 0.8% in pentobarbital-anesthetized rats, P < 0.05). Insulin-induced hypoglycemia significantly increased whole pancreatic blood flow in conscious rats, whereas islet blood flow remained unchanged and fractional islet blood flow was decreased (5.8 ± 0.5% in the basal state, 4.2 ± 0.4% during hypoglycemia, P < 0.001). Methylatropine pretreatment significantly increased islet blood flow during hypoglycemia by 181%. This result suggests that prevention of hypoglycemia-induced increase in islet perfusion may be mediated, at least in part, by a cholinergic, vagal muscarinic mechanism.

Pancreatic islet blood flow in normal and obese-hyperglycemic (ob/ob) mice

1996 ◽  
Vol 271 (6) ◽  
pp. E990-E995 ◽  
Author(s):  
P. O. Carlsson ◽  
A. Andersson ◽  
L. Jansson
Keyword(s):  
Blood Flow ◽  
Blood Perfusion ◽  
Pancreatic Tissue ◽  
Pancreatic Blood Flow ◽  
Flow Measurements ◽  
Islet Mass ◽  
Arterial Blood ◽  
Islet Blood Flow ◽  
Different Strains ◽  
Blood Flow Measurements

The present study evaluated whether a microsphere technique could be used for islet blood flow measurements in anesthetized mice. When this was confirmed, we applied the technique in different strains of mice. Approximately 9 x 10(4) microspheres could be given without interfering with mean arterial blood pressure. Mixing of the microspheres with arterial blood was adequate, and the extraction of microspheres in capillary beds was nearly 100%. In NMRI mice whole pancreatic blood flow was estimated to be 0.54 +/- 0.11 ml.min-1.g pancreatic tissue-1 and islet blood flow to be 18 +/- 4 microliters.min-1.g pancreas-1 (n = 12 animals per experiment), whereas corresponding values in lean C57Bl/6 mice were twice as high. In C57Bl/6 mice glucose (3 g/kg iv) doubled islet blood flow without affecting whole pancreatic blood flow, whereas no effect was seen after an equimolar dose of 3-O-methylglucose. In obese-hyperglycemic C57Bl/6 mice, islet blood flow was more than five times higher than in the lean C57Bl/6 mice when expressed as blood flow per gram pancreas. However, when islet blood perfusion was corrected for islet weight, it was lower in the obese than in the lean mice, suggesting an impaired ability in obese mice to increase blood flow in concert with the increased islet mass. This may contribute to the insufficient insulin secretion and resulting hyperglycemia seen in these animals.

scholarly journals Lack of compensatory increase in islet blood flow and islet mass in GK rats following 60% partial pancreatectomy

2005 ◽  
Vol 184 (2) ◽  
pp. 319-327 ◽  
Author(s):  
Annika M Svensson ◽  
Claes-Göran Östenson ◽  
Birgitta Bodin ◽  
Leif Jansson
Keyword(s):  
Blood Flow ◽  
Glucose Tolerance ◽  
Wistar Rats ◽  
Pancreatic Blood Flow ◽  
Partial Pancreatectomy ◽  
Islet Mass ◽  
Gk Rats ◽  
Islet Blood Flow ◽  
Islet Volume ◽  
Female Wistar Rats

The effects of a 60% partial pancreatectomy were studied in hyperglycemic GK (Goto–Kakizaki) rats. Partial pancreatectomy or a sham operation was performed on 12-week-old female Wistar rats, GK rats or hybrids between male GK rats and female Wistar rats. Measurements of pancreatic blood flow and islet blood flow were performed by a microsphere technique 2 weeks after surgery. Glucose tolerance was decreased in hybrid compared with Wistar rats, and in GK rats compared with both hybrid and Wistar rats before surgery. Partial pancreatectomy induced minor changes in glucose tolerance. Wistar rats had a decreased islet mass following partial pancreatectomy. Both hybrid and GK rats showed a significant decrease in relative islet volume, but only GK rats in total islet mass, compared with Wistar rats 2 weeks after surgery. Pancreatic blood flow and islet blood flow did not significantly differ between sham-operated Wistar, hybrid or GK rats. After partial pancreatectomy, islet blood flow in relation to islet mass increased 3-fold in Wistar rats and 2-fold in hybrid rats. In contrast, GK rats showed no increase in islet blood flow following partial pancreatectomy. It is concluded that compensatory mechanisms after partial pancreatectomy are operating less effciently in hybrid and GK rats.

Effect of synthetic chicken vasoactive intestinal peptide on pancreatic blood flow and on exocrine and endocrine secretions of the pancreas in dogs

1983 ◽  
Vol 28 (8) ◽  
pp. 724-732 ◽  
Author(s):  
Kazutomo Inoue ◽  
Tamotsu Kawano ◽  
Koichi Shima ◽  
Teruji Kim ◽  
Takashi Suzuki ◽  
...  
Keyword(s):  
Blood Flow ◽  
Vasoactive Intestinal Peptide ◽  
Pancreatic Blood Flow

Thyrotropin-releasing hormone in the dorsal vagal complex stimulates pancreatic blood flow in rats

2005 ◽  
Vol 131 (1-3) ◽  
pp. 74-81 ◽  
Author(s):  
Masashi Yoneda ◽  
Manabu Goto ◽  
Kimihide Nakamura ◽  
Shiro Yokohama ◽  
Toru Kono ◽  
...  
Keyword(s):  
Blood Flow ◽  
Thyrotropin Releasing Hormone ◽  
Dorsal Vagal Complex ◽  
Pancreatic Blood Flow ◽  
Releasing Hormone

scholarly journals Glucose-dependent blood flow dynamics in murine pancreatic islets in vivo

2010 ◽  
Vol 298 (4) ◽  
pp. E807-E814 ◽  
Author(s):  
Lara R. Nyman ◽  
Eric Ford ◽  
Alvin C. Powers ◽  
David W. Piston
Keyword(s):  
Blood Flow ◽  
Blood Glucose ◽  
Pancreatic Islets ◽  
Fluorescent Protein ◽  
Yellow Fluorescent Protein ◽  
Cell Types ◽  
Β Cells ◽  
Islet Blood Flow ◽  
Significant Difference

Pancreatic islets are highly vascularized and arranged so that regions containing β-cells are distinct from those containing other cell types. Although islet blood flow has been studied extensively, little is known about the dynamics of islet blood flow during hypoglycemia or hyperglycemia. To investigate changes in islet blood flow as a function of blood glucose level, we clamped blood glucose sequentially at hyperglycemic (∼300 mg/dl or 16.8 mM) and hypoglycemic (∼50 mg/dl or 2.8 mM) levels while simultaneously imaging intraislet blood flow in mouse models that express green fluorescent protein in the β-cells or yellow fluorescent protein in the α-cells. Using line scanning confocal microscopy, in vivo blood flow was assayed after intravenous injection of fluorescent dextran or sulforhodamine-labeled red blood cells. Regardless of the sequence of hypoglycemia and hyperglycemia, islet blood flow is faster during hyperglycemia, and apparent blood volume is greater during hyperglycemia than during hypoglycemia. However, there is no change in the order of perfusion of different islet endocrine cell types in hypoglycemia compared with hyperglycemia, with the islet core of β-cells usually perfused first. In contrast to the results in islets, there was no significant difference in flow rate in the exocrine pancreas during hyperglycemia compared with hypoglycemia. These results indicate that glucose differentially regulates blood flow in the pancreatic islet vasculature independently of blood flow in the rest of the pancreas.

scholarly journals Innervation of the pancreas by substance P, enkephalin, vasoactive intestinal polypeptide and gastrin/CCK immunoractive nerves.

1979 ◽  
Vol 27 (9) ◽  
pp. 1283-1284 ◽  
Author(s):  
L I Larsson
Keyword(s):  
Blood Flow ◽  
Insulin Secretion ◽  
Substance P ◽  
Blood Vessels ◽  
Vasoactive Intestinal Polypeptide ◽  
Pancreatic Blood Flow ◽  
Major Site ◽  
Site Of Action ◽  
Immunocytochemical Studies ◽  
Intestinal Polypeptide

Immunocytochemical studies habe shown that many peptides which profoundly affect the endocrine and exocrine functions of the pancreas are localized to neurons. In the cat, such peptidergic nerves appear to innervate ganglia, islets and blood vessels of the pancreas, whereas their contributions to exocrine cells are minor. Our studies suggest that pancreatic ganglia represent one major site of action of the peptides and that, in addition, nerves containing the vasoactive intestinal polypeptide and gastrin/CCK-related peptides profoundly affect pancreatic blood flow and insulin secretion, respectively.

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