Question

Insulin can bind to receptors on the smooth muscle cells of arterioles which supply blood to the capillary beds of the skeletal muscle tissue. in doing so, insulin will activate nitric oxide synthase (enos) in those smooth muscle cells, leading to nitric oxide production and vasodilation.

a) True
b) False

Answer 1

The statement is true; insulin can bind to receptors on arteriole smooth muscle, leading to the activation of eNOS, production of nitric oxide, and vasodilation which facilitates skeletal muscle glucose uptake.

Step-by-step explanation:

The question asks whether it's true or false that insulin can bind to receptors on the smooth muscle cells of arterioles, leading to the activation of nitric oxide synthase and subsequent vasodilation. The answer is true. Insulin has a multifaceted role in the body beyond regulating blood glucose levels.

It binds to insulin receptors on target cells, which include not only skeletal muscle and adipose tissue but also the smooth muscle cells of arterioles. This interaction can cascade into the activation of nitric oxide synthase (eNOS), increasing the production of nitric oxide, which is a potent vasodilator. Vasodilation increases blood flow to tissues, including skeletal muscles, facilitating the uptake of glucose facilitated by the Glut-4 transporter in response to insulin.

Furthermore, the role of insulin in regulating blood flow is important for maintaining the concentration gradient required for glucose uptake by cells. By converting glucose into glucose-6-phosphate inside the cells, insulin ensures that blood glucose levels remain higher than within cells, promoting continual glucose movement into cells where it is needed. This is critical during the absorptive state when blood glucose levels rise due to nutrient absorption.

Answer 2

Insulin regulates glucose metabolism by promoting glucose uptake and storage in various cells including muscle cells, while also causing vasodilation through the activation of nitric oxide synthase in smooth muscle cells of arterioles. Option a) True is the correct answer.

Step-by-step explanation:

Insulin is a key hormone involved in the regulation of glucose metabolism. When food is ingested and glucose levels rise in the bloodstream, insulin is secreted by the pancreatic beta cells, initiating glucose absorption by liver, adipose, and muscle cells. Inside these cells, glucose is converted into glucose-6-phosphate to maintain a concentration gradient and promote glucose uptake from the blood, while also stimulating glucose storage as glycogen and promoting protein synthesis in muscles.

Furthermore, insulin plays a crucial role in vascular physiology. It can bind to insulin receptors on smooth muscle cells of arterioles, which supply blood to the capillary beds of skeletal muscles. Upon binding, insulin activates nitric oxide synthase (eNOS) in these cells, triggering the production of nitric oxide and leading to vasodilation. This process increases blood flow into tissues, especially during periods when muscle activity is high or when the metabolic demand increases. Therefore, the statement that insulin can bind to receptors on the smooth muscle cells of arterioles, activating eNOS and leading to nitric oxide production and vasodilation, is true.