Tuberc Respir Dis.  1996 Apr;43(2):123-127.

Signal Transduction Mechanisms Mediating Surfactant Phospholipid Secretion in Isolated Type II Cell

• Park SS

Abstract

Secretion of surfactant phospholipid can be stimulated by a variety of agonists acting via at least three different signal transduction mechanisms. These include the adenylate cyclase system with activation of cAMP-dependent protein kinase; activation of protein kinase C either directly or subsequent to activation of phosphoinositide-specific phospholipase C and generation of diacylglycerols and inositol trisphosphate; and a third mechanism that involves incresed Ca2+ levels and a calmodulin-dependent step. ATP stimulates secretion via all three mechanisms. The protein kinase C pathway is also coupled to phopholipase D which, acting on relatively abundant cellular phospholipids, generates diacylglycerols that further activate protein kinase C. Sustained protein kinase C activation can maintain phosphatidylcholine secretion for a prolonged period of time. It is likely that interactions between the different signaling pathways have an important role in the overall physiological regulation of surfactant secretion.

Keyword

Signal transduction mechanisms; Surfactant phospholipid secretion; Isolated type II cell

MeSH Terms

Adenosine Triphosphate
Adenylyl Cyclases
Cyclic AMP-Dependent Protein Kinases
Diglycerides
Inositol
Negotiating*
Phosphatidylcholines
Phospholipids
Protein Kinase C
Signal Transduction*
Type C Phospholipases
Adenosine Triphosphate
Cyclic AMP-Dependent Protein Kinases
Diglycerides
Inositol
Phosphatidylcholines
Phospholipids
Protein Kinase C
Type C Phospholipases