ENDOCRINE PHARMACOLOGY ,Adrenocorticotropic Hormone (ACTH)  

Adrenocorticotropic hormone (ACTH) is a peptide hormone produced by the anterior pituitary gland. Its primary function is to stimulate the adrenal cortex to secrete glucocorticoids, mainly cortisol, which play a crucial role in stress response, metabolism, and immune function. ACTH is regulated by the hypothalamic corticotropin-releasing hormone (CRH) and follows a diurnal rhythm, peaking in the early morning. It is also involved in the body's response to stress, with levels increasing during physical or emotional stress. Dysregulation of ACTH can lead to disorders such as Addison's disease, characterized by insufficient cortisol production, or Cushing's syndrome, resulting from excess cortisol. Understanding ACTH's role is vital for diagnosing and treating these endocrine disorders.