Question

Prorenin is secreted by
A) Zymogen cells
B) Sertoli cells
C) Islets of Langerhans
D) Hepatocytes

Answer 1

Hint: A protein that constitutes the precursor for rennin is called prorenin. It is a hormone that activates the renin which serves for raising blood pressure. It is converted into renin with the help of juxtaglomerular cells which are the muscle cells that are specialized and present in the afferent, but also the efferent. Prorenin is a large molecule.

Complete answer:
Let us analyze from the given options:
A) Zymogens cells – The chief or peptic cells usually present in the stomach wall and secrete gastric juices, which are a mixture of hydrochloric acid and gastric digestive enzymes as proenzymes (zymogens) – pepsinogens, prorenin, lipase ad mucus. Prorenin is only secreted in young mammals or infants, not in adult mammals.
B) Sertoli cells – It secretes the hormone Inhibin. It also provides support and nourishes the sperm cells that are immature by giving them nutrients and blood products.
C) Islets of Langerhans – The endocrine part of the pancreas consists of groups of islets of Langerhans. It consists of four types of cells – alpha cells (secretes glucagon hormone), beta cells (secretes insulin), delta cells (secretes somatostatin), pancreatic polypeptide cells (secretes pancreatic polypeptide).
D) Hepatocytes – These are the liver cells that are responsible for the production of proteins in the body which are helpful in various functions of the body. It produces bile.

So, the correct answer is option (A) i.e, Zymogens.

Note: HCL kills the bacteria and other harmful organisms that are present in the food. It also converts pepsinogen and prorenin into pepsin and rennin respectively. Such activation is known as an autocatalytic reaction. Pepsin and rennin are absent in invertebrates.