What is the Difference Between Renin and Rennin

The key difference between renin and rennin is that renin is a hormone involved in the regulation of arterial blood pressure, while rennin is an enzyme that is useful in milk coagulation.

There are various chemicals in the animal body that enable certain key functions necessary for the sustenance of life. These chemicals are mainly of two types: hormones and enzymes. The main difference between hormones and enzymes is that hormones act as chemical messengers which trigger various functions in the body while enzymes act as catalysts for different biochemical reactions in the body. Renin is a hormone found in mammals, including humans, while rennin is an enzyme found in ruminant animals.

CONTENTS

1. Overview and Key Difference
2. What is Renin
3. What is Rennin
4. Similarities – Renin and Rennin
5. Renin vs Rennin in Tabular Form
6. Summary – Renin vs Rennin

What is Renin?

Renin is a physiological hormone that helps in the regulation of arterial blood pressure. It is also known as angiotensinogenase. It is an aspartic protease protein secreted from the kidneys. Renin participates in the renin-angiotensin-aldosterone system (RAAS), which regulates the body’s arterial blood pressure. The primary structure of the renin precursor consists of 406 amino acids. However, a mature renin contains 340 amino acids and has a mass of 37 kDa. Moreover, renin is secreted from specialized cells in the kidney known as juxtaglomerular cells. Normally, human renin is secreted in two pathways: a constitutive pathway for the secretion of the precursor prorenin and a regulated pathway for the secretion of mature renin.

Renin primarily activates the renin-angiotensin-aldosterone system by using its enzymatic activity. Renin endopeptidase activity cleaves angiotensinogen produced by the liver to yield angiotensin I. Then, angiotensin I further transforms to angiotensin II by the action of ACE (angiotensin-converting enzyme), which is found in the capillaries of lungs. Angiotensin II constricts blood vessels, increases the secretion of ADH and aldosterone, and stimulates the hypothalamus to activate the thirst reflex. Furthermore, all these events lead to an increase in arterial blood pressure.

What is Rennin (Chymosin)?

Rennin is an enzyme found in ruminant animals and is useful in milk coagulation. It is also known as chymosin. It is an aspartic endopeptidase protein belonging to the MEROPS A1 family. This enzyme is produced by newborn ruminant animals in the lining of abomasums. Rennin is usually produced by these newborn ruminants to curdle the milk they ingest, allowing a longer residence in the bowels. Ultimately, the action of rennin allows better absorption of milk’s nutrients in ruminant animals.

Humans use rennin widely in the production of cheese. Now, bovine chymosin is produced recombinantly using E. coli, Aspergillus niger, and Kluyverromyces lactis. By 2008, in US and Britain, 80% to 90% of commercially made cheeses were manufactured by using recombinant chymosin. Furthermore, recombinant chymosin provides additional benefits such as higher production yield, better curd texture, and reduced bitterness.

What are the Similarities Between Renin and Rennin?

• Renin and rennin are chemicals in the animal body that perform key functions necessary for the sustenance of life.
• Both are aspartic protease proteins.
• Both have endopeptidase activity.
• They are found only in animals.

What is the Difference Between Renin and Rennin?

Renin is a hormone that involves in the regulation of arterial blood pressure, while rennin is an enzyme that is useful in milk coagulation. Thus, this is the key difference between renin and rennin. Furthermore, the molecular weight of renin is approximately 37 kDa, while the molecular weight of renin is rennin is approximately 40 kDa.

The below infographic presents the differences between renin and rennin in tabular form for side by side comparison.

Summary – Renin vs Rennin

Chemicals such as hormones and enzymes in the animal body enable certain key functions necessary for the sustenance of life. Renin is a hormone that involves in the regulation of arterial blood pressure, while rennin is an enzyme that is useful in milk coagulation. So, this is the key difference between renin and rennin.

Reference:

1. Persson, Pontus B. “Renin: Origin, Secretion and Synthesis.” The Journal of Physiology, Blackwell Science Inc.
2. “Rennin.” Encyclopædia Britannica, Encyclopædia Britannica, Inc.

Image Courtesy:

1. “Renin-angiotensin-aldosterone system” By A. Rad (me) – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Clothbound Cheddar – Rennet (4790811140)” By Rebecca Siegel – Clothbound Cheddar – Rennet (CC BY 2.0) via Commons Wikimedia