Question

Which of the following is/are characteristics of Histamine?

1. It is also responsible for the nasal congestion associated with the common cold and allergic response to pollen. 

2. It is a potent vasodilator.

3. Histamine is produced by basophils and is found in tissues that are connected nearby.

Select the correct answer using the code given below.

1. 1 only
2. 1 and 3
3. 1, 2 and 3
4. 2 and 3

Answer 1

Correct Answer - Option 3 : 1, 2 and 3

The correct answer is 1, 2 and 3.

• Histamine is produced by basophils and is found in tissues that are connected nearby. The permeability of white blood cells is increased by histamine and this allows the pathogens to get engaged with the infected tissues. Hence, statement 3 is correct.
• Histamine is a potent vasodilator. Hence, Statement 2 is correct.
• It has various functions.
  • It contracts the smooth muscles in the bronchi and gut and relaxes other muscles, such as those in the walls of fine blood vessels.
  • Histamine is also responsible for the nasal congestion associated with the common cold and allergic response to pollen. Hence, Statement 1 is correct.
• Synthetic drugs, brompheniramine (Dimetapp) and terfenadine (Seldane), act as antihistamines.
  • They interfere with the natural action of histamine by competing with histamine for binding sites of receptors where histamine exerts its effect.
• Now the question that arises is, “Why do the above-mentioned antihistamines not affect the secretion of acid in the stomach?”
  • The reason is that antiallergic and antacid drugs work on different receptors.