Microsphere distribution in the pancreas of anesthetized rats. Alloxan stimulates the blood flow to all islets whereas glucose only affects the blood perfusion of a subgroup of islets.
CONCLUSIONS
Islet blood flow stimulation induced by alloxan leads to an increased blood perfusion in all islets, whereas glucose induces a flow increase only in a subgroup of islets.


BACKGROUND
The aim of the present study was to investigate if an increased islet blood flow was associated with an enhanced total number of perfused islets, or whether only a subgroup of the islets increased their blood flow.


METHODS
For this purpose, the whole pancreatic and islet blood flow was measured with a microsphere technique (4.5 x 10(5) microspheres/kg body wt) in anesthetized Sprague-Dawley rats. Blood flow measurements were made 3 min after an i.v. injection of 1 mL of saline, alloxan (75 mg/kg body wt), or D-glucose (300 mg/mL).


RESULTS
Alloxan reduced whole pancreatic blood flow by 50%, but almost doubled islet blood flow. Glucose did not affect whole pancreatic blood flow, but increased islet blood flow 100%. Approximately 10% of the islets in control and glucose-injected rats contained microspheres, compared with about 25% in alloxan-injected rats (P < 0.001). When the islets containing a certain number of microspheres were compared, alloxan induced a homogeneous shift of the curve to the right, i.e., increased the number of islets that contained all amounts of microspheres. Glucose preferentially increased only the fraction of islets containing > or = 3 microspheres.
Jansson
L
L
Department of Medical Cell Biology, Uppsala University, Sweden.
D000496:Alloxan / Q000494:pharmacology*; D000818:Animals; D001786:Blood Glucose / Q000032:analysis / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D005947:Glucose / Q000494:pharmacology*; D007515:Islets of Langerhans / Q000098:blood supply* / Q000187:drug effects; D008297:Male; D008863:Microspheres; D010179:Pancreas / Q000098:blood supply* / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D012039:Regional Blood Flow
D001786:Blood Glucose; D000496:Alloxan; D005947:Glucose