Question

Tell how increased glucose levels in b cells leads to increased insulin secretion. Be sure to

include the specifics of relevant gated ion channels.

Answer 1

In our body insulin is secreted by the insulin gene (INS). In pancreas, insulin is secreted from the β-cells of islets of Langerhans. The secetion of insulin is controlled by the glucose level in plasma. When glucose level is high, glucose uptake by β-cells also incresed. This increased glucose uptake will results in increased glucose metabolism. Now, we also have ATP sensitive channels in palsma membranes. which is called as K_ATP channel. K_ATP acts as a mechanical sensor. K_ATP chanels are related to pancreatic β-cells. For eg, when glucose level is low, K_ATP channels are open and inhibit insulin release , whereas increased glucose level leads to blockage of K_ATP channels. Thus when glucose metabolism is high, K_ATP channels are closed, as a result voltage-gated Ca²⁺ channels are opened. This will results in increased Ca²⁺ influx and insulin secretion.

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