In anesthetized rats, topical application of insulin (120 ng/ml) to the brain (via craniotomy) caused an increase (appro
Posted: Tue Jul 12, 2022 1:29 pm
In anesthetized rats, topical application of insulin (120 ng/ml)to the brain (via craniotomy) caused an increase (approximately30%) in cortical blood flow (Katakam et al., Journal of CerebralBlood Flow & Metabolism (2009) 29, 1955–1967). Assessment ofthe reactivity of isolated rat cerebral arteries showed a biphasicdose-response to insulin, with an initial vasoconstriction at0.1 ng/mL, followed by vasodilation at 1 to 100 ng/mL.
A. What cells in the vascular wall mediate the vasoconstrictorresponse to insulin?
B. What cells in the vascular wall contribute to thevasodilatory response to insulin?
C. What pathways are likely to be involved in mediating thevasodilation to insulin?
D. Could the contribution of these vasodilatory pathways beseparated and evaluated experimentally?
E. What role would insulin receptors play in mediating itsbiphasic response, i.e., vasoconstriction followed byvasodilation?
A. What cells in the vascular wall mediate the vasoconstrictorresponse to insulin?
B. What cells in the vascular wall contribute to thevasodilatory response to insulin?
C. What pathways are likely to be involved in mediating thevasodilation to insulin?
D. Could the contribution of these vasodilatory pathways beseparated and evaluated experimentally?
E. What role would insulin receptors play in mediating itsbiphasic response, i.e., vasoconstriction followed byvasodilation?