Introduction:
Hormones play a crucial role in various physiological processes in the human body. They are chemical messengers that are secreted by endocrine glands, travel through the bloodstream, and bind to specific receptors to initiate a response in target tissues or organs. While most hormones are produced and released in their active form, there are certain hormones that are initially synthesized as inactive precursors or prohormones.

Prohormones:
Prohormones are biologically inactive hormone precursors that undergo enzymatic conversion to their active forms within the body. These prohormones are typically synthesized in endocrine glands and packaged into secretory vesicles. They are released into the bloodstream and subsequently converted into their active hormone forms.

Examples of Hormones Produced in Inactive Form:
Several hormones are produced in their inactive forms and require specific enzymatic processes to be activated. Some examples include:

1. Thyroxine (T4): The thyroid gland produces thyroxine, also known as T4, in an inactive form. T4 is then converted into its active form, triiodothyronine (T3), through the removal of one iodine molecule. This conversion occurs primarily in the liver and other peripheral tissues.

2. Insulin: Insulin, an essential hormone for regulating blood sugar levels, is initially synthesized as preproinsulin. Preproinsulin is then processed to proinsulin, which is still inactive. Proinsulin is subsequently cleaved to form active insulin and C-peptide, a byproduct.

3. Angiotensinogen: Angiotensinogen is a hormone produced by the liver. It is released into the bloodstream and converted into angiotensin I by the enzyme renin. Angiotensin I is further converted to angiotensin II, the active form responsible for regulating blood pressure and fluid balance.

4. Proopiomelanocortin (POMC): POMC is a prohormone produced in the anterior pituitary gland and other tissues. It undergoes enzymatic cleavage to generate several biologically active peptides, including adrenocorticotropic hormone (ACTH), melanocyte-stimulating hormone (MSH), and endorphins.

Importance of Inactive Forms:
The production of hormones in inactive forms provides several advantages:

1. Storage and transport: Inactive prohormones can be stored in endocrine glands or secretory vesicles until they are needed. This allows for the efficient release and transport of hormones throughout the body.

2. Regulation and control: The conversion of prohormones to active hormones is a tightly regulated process. It allows for precise control over hormone production, ensuring that the appropriate levels are released in response to specific stimuli or physiological needs.

3. Extended half-life: Inactive prohormones often have longer half-lives compared to their active counterparts. This enables a sustained release of active hormones over a longer duration, providing a more prolonged physiological effect.

Conclusion:
Several hormones are synthesized and released in their inactive prohormone forms. These prohormones undergo enzymatic conversion to their active hormone forms, allowing for storage,

Thyroxine becz. it will store in body early