Question

Histamine has receptors in the hypothalamus, RAS system, stomach, blood vessels, and bronchioles. What creates histamine's differing effects seen in each of these areas? ______

A) They are dependent on which cell secretes the histamine.
B) All of the effects are a result of membrane dehydration.
C) There are different message transduction systems.
D) Histamine recombines with other endogenous substances once inside the target cell.
E) Each tissue is different, so no two can have the same effect.

Answer 1

Histamine's differing effects in the body are due to different message transduction systems linked to various histamine receptors like H1 and H2, which are distributed in different tissues and elicit distinct cellular responses upon activation. The correct option s C.

Step-by-step explanation:

The differing effects of histamine in various areas of the body are due to different message transduction systems.

This means, there are diverse histamine receptors (such as H1, H2, H3, and H4) that influence different signal transduction pathways within cells in different tissues.

These receptors, when bound to histamine, elicit various responses from the cell, depending on the specific receptor type and tissue in which it's located.

For example, the interaction of histamine with H1 receptors can cause symptoms related to allergies, such as itching, sneezing, and bronchiole constriction leading to breathing difficulties.

The vasodilation and increased permeability of blood vessels, as well as secretion in the stomach, are mediated via H2 receptors. Therefore, the correct answer is C) There are different message transduction systems. The correct option s C.