Which hormone is primarily associated with regulating kidney function and blood pressure?

Erythropoietin is primarily associated with the regulation of kidney function and blood pressure due to its role in stimulating red blood cell production in the bone marrow, which is crucial for maintaining adequate oxygen delivery to tissues. While it is best known for its erythropoietic function, erythropoietin also has a role in regulating renal blood flow and vascular resistance, thereby influencing blood pressure.

The kidneys play a significant role in blood pressure regulation through the renin-angiotensin-aldosterone system, and erythropoietin can modulate the effects of this system, impacting blood volume and pressure. Therefore, it connects kidney function and blood pressure regulation through its various physiological effects.

Other hormones have more specialized functions; for instance, thyroid hormone has a broader influence on metabolism rather than direct kidney function regulation, insulin primarily regulates glucose metabolism, and adrenaline (epinephrine) is involved in acute stress responses, affecting heart rate and blood flow rather than directly controlling kidney function. Thus, erythropoietin is the hormone most directly relevant to the regulation of kidney function and blood pressure.