title: Guanylyl cyclases, nitric oxide, natriuretic peptides, and airway smooth muscle function.
abstract: Airway smooth muscle (ASM) plays an important role in asthma pathophysiology through its contractile and proliferative functions. The cyclic nucleotides adenosine 3',5'-cyclic monophosphate (cAMP) and guanosine 3',5'-cyclic monophosphate (cGMP) are second messengers capable of mediating the effects of a variety of drugs and hormones. There is a large body of evidence to support the hypothesis that cAMP is a mediator of the ASM's relaxant effects of drugs, such as beta2-adrenoceptor agonists, in human airways. Although most attention has been paid to this second messenger and the signal transduction pathways it activates, recent evidence suggests that cGMP is also an important second messenger in ASM with important relaxant and antiproliferative effects. Here, we review the regulation and function of cGMP in ASM and discuss the implications for asthma pathophysiology and therapeutics. Recent studies suggest that activators of soluble and particulate guanylyl cyclases, such as nitric oxide donors and natriuretic peptides, have both relaxant and antiproliferative effects that are mediated through cGMP-dependent and cGMP-independent pathways. Abnormalities in these pathways may contribute to asthma pathophysiology, and therapeutic manipulation may complement the effects of beta2-adrenoceptor agonists.
authors.affiliation: Department of Respiratory Medicine, Al-Mansourah University, Al-Dakahlia, Egypt.
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Hamad
authors.forename: Andrew
authors.initials: A
authors.lastname: Clayton
authors.forename: Baharul
authors.initials: B
authors.lastname: Islam
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Knox
mesh_terms: D000818:Animals; D009320:Atrial Natriuretic Factor / Q000502:physiology*; D000242:Cyclic AMP / Q000502:physiology; D006152:Cyclic GMP / Q000502:physiology; D006162:Guanylate Cyclase / Q000378:metabolism*; D006801:Humans; D001239:Inhalation / Q000502:physiology; D009130:Muscle, Smooth / Q000502:physiology*; D009569:Nitric Oxide / Q000502:physiology*; D012143:Respiratory Physiological Phenomena; D015290:Second Messenger Systems / Q000502:physiology
chemical_list: D009569:Nitric Oxide; D009320:Atrial Natriuretic Factor; D000242:Cyclic AMP; D006162:Guanylate Cyclase; D006152:Cyclic GMP