Question

Half life of insulin

• A. \(<1 \, \text{min} \)
• B. 5-6 mins
• C. 30-40 mins
• D. 1-2 hrs

Hint:

Insulin has a short half-life, typically 5-6 minutes, which is important for regulating its therapeutic effects.

Answer 1

The Correct Option is B

Step 1: Understanding the half-life of insulin.
The half-life of insulin is relatively short compared to other hormones. It is typically around 5-6 minutes in the bloodstream after administration.
Step 2: Analyzing the options.
(1) \(<1 \, \text{min} \): Incorrect, insulin's half-life is longer than 1 minute.
(2) 5-6 mins: Correct — The half-life of insulin is approximately 5-6 minutes.
(3) 30-40 mins: Incorrect, insulin's half-life is much shorter.
(4) 1-2 hrs: Incorrect, this is far longer than insulin's actual half-life.
Step 3: Conclusion.
The correct half-life of insulin is (2) 5-6 mins.

Answer 2

Insulin's plasma half-life reflects how quickly it is cleared from the bloodstream after secretion or administration. Let's evaluate each time range against this.

1. \(<1\,\text{min}\): A half-life this short would mean insulin is cleared almost instantaneously, which is too rapid to allow it to exert its physiological effects on target tissues.
2. 5-6 mins: This range reflects insulin's actual plasma clearance, allowing enough circulation time for it to bind receptors on liver, muscle, and fat tissue before being rapidly degraded, primarily by the liver and kidneys.
3. 30-40 mins: This is considerably longer than insulin's actual clearance time and would be more consistent with a longer-acting peptide hormone.
4. 1-2 hrs: This is far too long for endogenous insulin, which is known for its rapid turnover in the bloodstream.

Insulin's known rapid clearance from plasma matches the 5-6 minute range.

Therefore, the correct answer is 5-6 mins.