Fig. 4.

Endothelium-dependent relaxation assessment of vascular rings isolated from treated STZ-induced diabetic rats. Rats were treated as described in Fig. 3. At 21 days, animals were euthanized and segments of abdominal aorta were dissected for vessel reactivity studies. Aortic rings were pre-constricted with norepinephrine and aortic vessel reactivity was measured in the presence of increasing concentrations of acetylcholine (10⁻¹⁰-10⁻⁶ M).