Which does not act 2nd messenger?
a. Insostol triphosphate is used as a secondary messenger in biological cells. It is produced as a result of hydrolysis of phosphatidyl 4,5 biphosphate. IP3 activates its receptors on sarcoplasmic reticulum or endoplasmic reticulum.
b. This increases the calcium release. It helps in mobilizing calcium from storage granules and regulates cell profiliferation. It also assists in contraction of muscles.
c. Insositol is found in many foods including cereals. It is a precursor of inositol phosphate, phosphatidyl insositol and phosphatidyl inositol phosphate. cAMP is most common secondary messenger followed by cGMP.
d. A membrane bound enzyme named phospholipase C acts upon phosphatidyl inositol-bisphosphate and leads to formation of DAG.
e. Guanyl cyclase is not a secondary massager but an enzyme that mediates the conversion of guanosine triphosphate (GTP) to 3',5'-cyclic guanosine monophosphate (cGMP) and pyrophosphate ((BG Katzung, Basic and Clinical Pharmacology; 10th Edition’ 2007, pp-25).