Doelcelreactie op hormonen

Hormones bind to receptors on a target cell’s surface or interior and initiate various cellular responses.                          

One way cells regulate these effects is by altering the amount of the receptor expressed in the cell.

High hormone levels can lead to a gradual decline in the number of receptors for a given hormone on the cells —a process called down-regulation.

In contrast, when hormone levels are low, cells may produce more of a given receptor to increase cellular sensitivity through up-regulation.

Hormones can also interact with other types of hormones to create diverse cellular responses.

Some hormones are permissive, where the presence of one hormone allows another to exert its effects. For example, epinephrine needs thyroid hormones to stimulate lipolysis effectively in target cells.

Others, such as follicle-stimulating hormone and testosterone, act synergistically to produce an amplified response, in this case, normal production of sperms.

In contrast, some hormones are antagonistic, producing opposing responses. For example, insulin stimulates a decrease in blood glucose, while glucagon increases it.