Thus, higher hormone concentration alone cannot trigger the negative feedback mechanism.

However, as it relates to advancing age, the condition is generally attributed to three factors: motor unit restructuring, protein deficiency and changes in hormone concentrations.

Narcolepsy is a disabling sleep disorder that causes excessive daytime sleepiness and is linked to abnormal hormone concentrations and changes in nervous system activity.

The hormone concentration within the hemolymph may be affected by esterases.

Reduction of thyrotropin-releasing hormone concentrations in central nervous system of African lungfish during estivation.

An elevated parathyroid hormone concentration results in a depletion of calcium in bone structures and thus a higher calcium concentration in the blood.

Additionally, it was found that the receptor number was altered because of a change in both serotonin and thyroid-stimulating hormone concentrations.

Over time, this self-induced loss of target cell receptors for insulin reduces the target cell's sensitivity to the elevated hormone concentration.