Which of the following is a potent vasodilator?

The correct answer is Histamine.

Key Points

• Histamine is a potent vasodilator that plays a significant role in the immune response.
• It is released by mast cells and basophils during allergic reactions and inflammation.
• Histamine causes the dilation of blood vessels, which increases blood flow to affected tissues.
• This vasodilation results in symptoms such as redness, swelling, and warmth in the area of inflammation.
• Histamine also increases the permeability of blood vessels, allowing immune cells to access the site of infection or injury.

Additional Information

• Noradrenaline:
  • Noradrenaline, also known as norepinephrine, is a neurotransmitter and hormone involved in the body's stress response.
  • It primarily acts as a vasoconstrictor, narrowing blood vessels and increasing blood pressure.
  • Noradrenaline is released from the adrenal medulla and sympathetic nerve endings.
• Cimetidine:
  • Cimetidine is an H2 receptor antagonist used to reduce stomach acid production.
  • It is commonly used to treat conditions such as peptic ulcers and gastroesophageal reflux disease (GERD).
• Ranitidine:
  • Ranitidine is another H2 receptor antagonist that decreases stomach acid production.
  • It is used to manage and treat peptic ulcers, GERD, and Zollinger-Ellison syndrome.
• Vasodilation:
  • Vasodilation is the widening of blood vessels, which decreases blood pressure.
  • This process is essential for regulating blood flow and ensuring adequate oxygen and nutrient delivery to tissues.