Influence of insulin on the microvascular response to inflammatory mediators in neonatal streptozotocin diabetic rats.
OBJECTIVE
To investigate the effect of insulin on microvascular responses to inflammatory mediators in a model of type 2 diabetes mellitus.


METHODS
We used the neonatal streptozotocin (n-STZ)-induced diabetes model. Diabetes was induced in male newborn (2-day-old) Wistar rats through STZ administration. Experiments were performed 10-12 weeks later.


METHODS
Rats were divided into control (sham-injected) and study (n-STZ) groups. Using a closed-circuit video camera coupled to a microscope, changes in mesenteric arteriolar and venular diameters induced by topical application of the inflammatory mediators histamine, bradykinin and platelet-activating factor were assessed in chloral hydrate-anesthetized rats.


METHODS
The n-STZ rats received NPH insulin s.c. for either 4 h or 12 days.


RESULTS
Impaired arteriole and venule responses to the inflammatory mediators tested were observed in n-STZ rats. Both acute and chronic insulin treatment corrected the alterations.


CONCLUSIONS
We conclude that insulin is beneficial, restoring microvascular reactivity to inflammatory mediators in type 2 diabetes.
Rastelli
V Milan Ferreira
VM
Department of Pharmacology, Institute of Biomedical Science, Cidade Universitária, University of São Paulo. Av. Prof Lineu Prestes, 1524, 05508-900, São Paulo, Brazil.
Akamine
E Hiromi
EH
Oliveira
M Aparecida
MA
Nigro
D
D
Passaglia
R de Cássia Tostes
Rde C
Carvalho
M H Catelli
MH
Fortes
Z B
ZB
D000818:Animals; D000831:Animals, Newborn; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000139:chemically induced / Q000503:physiopathology*; D018836:Inflammation Mediators / Q000494:pharmacology*; D007328:Insulin / Q000097:blood / Q000494:pharmacology*; D008297:Male; D008833:Microcirculation / Q000187:drug effects*; D010972:Platelet Activating Factor / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013311:Streptozocin / Q000494:pharmacology
D001786:Blood Glucose; D018836:Inflammation Mediators; D007328:Insulin; D010972:Platelet Activating Factor; D013311:Streptozocin