Sucrose-stimulated subsecond transient increase in cGMP level in rat intact circumvallate taste bud cells

2000 ◽  
Vol 279 (1) ◽  
pp. C120-C125 ◽  
Author(s):  
Valery Krizhanovsky ◽  
Orly Agamy ◽  
Michael Naim
Keyword(s):  
Guanylyl Cyclase ◽  
Soluble Guanylyl Cyclase ◽  
Sweet Taste ◽  
Camp Level ◽  
Taste Bud ◽  
Pde4 Inhibitor ◽  
Cgmp Level ◽  
Time Range ◽  
Taste Transduction ◽  
Transient Elevation

Initial sweet taste transduction is expected to occur in the subsecond time range. We demonstrate a rapid and transient (75–250 ms) increase of cGMP (but not cAMP) level in rat intact circumvallate taste cells after stimulation by sucrose. This rapid increase does not occur in nonsensory epithelial cells. Pretreatment with a nonspecific phosphodiesterase (PDE) inhibitor (IBMX), a specific cAMP-PDE4 inhibitor (denbufylline), or an adenylyl cyclase activator (forskolin) all increased basal cAMP and abolished the sucrose-stimulated cGMP increase at 150 ms. Pretreatment with a soluble guanylyl cyclase inhibitor (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one) reduced, whereas a specific cGMP-PDE inhibitor (zaprinast) abolished, the sucrose-stimulated cGMP increase. It is proposed that cGMP is involved in the initial stage of sugar taste transduction and that cGMP is more significant than cAMP at this stage. Activation of soluble guanylyl cyclase and inhibition of cGMP-PDE may be involved in the transient elevation of cGMP in response to sucrose stimulation. Moreover, it appears that cAMP level must remain low for sucrose to stimulate an increase in cGMP.

Nitric oxide-independent activation of soluble guanylyl cyclase contributes to endotoxin shock in rats

1998 ◽  
Vol 275 (4) ◽  
pp. H1148-H1157 ◽  
Author(s):  
Chin-Chen Wu ◽  
Shiu-Jen Chen ◽  
Mao-Hsiung Yen
Keyword(s):  
Nitric Oxide ◽  
Smooth Muscle ◽  
Guanylyl Cyclase ◽  
Ex Vivo ◽  
Specific Inhibitor ◽  
Soluble Guanylyl Cyclase ◽  
Treated Group ◽  
Cgmp Level ◽  
Vascular Hyporeactivity

We investigated whether a complete inhibition of nitric oxide (NO) formation caused by bacterial endotoxin (lipopolysaccharide, LPS) in vivo prevents the hypotension and restores the vascular hyporeactivity to normal in vivo and ex vivo. The combination of dexamethasone (Dex; 3 mg/kg at 30 min before LPS) plus aminoguanidine (AG; 15 mg/kg at 2 h after LPS) inhibited the overproduction of nitrate (an indicator of NO) in the plasma and aortic smooth muscle and also prevented the development of the delayed hypotension in rats treated with LPS for 6 h. However, the vascular hyporeactivity to norepinephrine (NE) was only partially improved either in vivo or ex vivo in endotoxemic rats treated with Dex plus AG. Pretreatment of aortic rings with N ω-nitro-l-arginine methyl ester (l-NAME) or 1 H-[1,2,4]oxidazolo[4,3-a]quinoxalin-1-one (ODQ) enhanced the contraction to NE in rings obtained from LPS-treated rats, but not in those from Dex plus AG-treated endotoxemic rats. Methylene blue, an inhibitor of soluble guanylyl cyclase (GC), completely restored contractions to NE and aortic cGMP levels to normal either in LPS-treated rats or in Dex plus AG-treated endotoxemic rats, whereas the cGMP level was partially inhibited by ODQ in LPS-treated rats only. These results suggest that non-NO mediator(s) also activates soluble GC during endotoxemia. Interestingly, we found that in the presence of tetraethylammonium (an inhibitor of K+ channels) plusl-NAME or charybdotoxin [a specific inhibitor of large-conductance Ca2+-activated K+(KCa) channels] plus ODQ, the vascular hyporeactivity to NE in the LPS-treated group was also completely restored to normal. In addition, in the presence ofl-NAME or ODQ, the vascular hyporeactivity to high K+ was abolished in rings from the LPS-treated group. These results suggest that LPS causes the production of other mediator(s), in addition to NO, which also stimulates soluble GC (i.e., increases the formation of cGMP) and then activates the large-conductance KCa channels in the vascular smooth muscle causing vascular hyporeactivity.

scholarly journals Maturation, inactivation, and recovery mechanisms of soluble guanylyl cyclase

2021 ◽  
Vol 296 ◽  
pp. 100336
Author(s):  
Dennis J. Stuehr ◽  
Saurav Misra ◽  
Yue Dai ◽  
Arnab Ghosh
Keyword(s):  
Guanylyl Cyclase ◽  
Soluble Guanylyl Cyclase ◽  
Recovery Mechanisms

scholarly journals Cyclic Guanosine Monophosphate Modulates Locomotor Acceleration Induced by Nitric Oxide but not Serotonin in Clione limacina Central Pattern Generator Swim Interneurons

2020 ◽  
Author(s):  
Thomas J Pirtle ◽  
Richard A Satterlie
Keyword(s):  
Nitric Oxide ◽  
Central Pattern Generator ◽  
Guanylyl Cyclase ◽  
Signal Transduction Pathway ◽  
Soluble Guanylyl Cyclase ◽  
Cyclic Guanosine Monophosphate ◽  
Pattern Generator ◽  
Guanosine Monophosphate ◽  
Cellular Changes ◽  
Clione Limacina

Abstract Typically, the marine mollusk, Clione limacina, exhibits a slow, hovering locomotor gait to maintain its position in the water column. However, the animal exhibits behaviorally relevant locomotor swim acceleration during escape response and feeding behavior. Both nitric oxide and serotonin mediate this behavioral swim acceleration. In this study, we examine the role that the second messenger, cGMP, plays in mediating nitric oxide and serotonin-induced swim acceleration. We observed that the application of an analog of cGMP or an activator of soluble guanylyl cyclase increased fictive locomotor speed recorded from Pd-7 interneurons of the animal’s locomotor central pattern generator. Moreover, inhibition of soluble guanylyl cyclase decreased fictive locomotor speed. These results suggest that basal levels of cGMP are important for slow swimming and that increased production of cGMP mediates swim acceleration in Clione. Because nitric oxide has its effect through cGMP signaling and because we show herein that cGMP produces cellular changes in Clione swim interneurons that are consistent with cellular changes produced by serotonin application, we hypothesize that both nitric oxide and serotonin function via a common signal transduction pathway that involves cGMP. Our results show that cGMP mediates nitric oxide-induced but not serotonin-induced swim acceleration in Clione.

scholarly journals Insights into Soluble Guanylyl Cyclase Activation Derived from Improved Heme-Mimetics

2013 ◽  
Vol 56 (21) ◽  
pp. 8948-8952 ◽  
Author(s):  
Margarete von Wantoch Rekowski ◽  
Vijay Kumar ◽  
Zongmin Zhou ◽  
Johann Moschner ◽  
Antonia Marazioti ◽  
...  
Keyword(s):  
Guanylyl Cyclase ◽  
Soluble Guanylyl Cyclase ◽  
Cyclase Activation

scholarly journals An engineered membrane-bound guanylyl cyclase with light-switchable activity

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Yuehui Tian ◽  
Georg Nagel ◽  
Shiqiang Gao
Keyword(s):  
Guanylyl Cyclase ◽  
Green Light ◽  
Chemical Properties ◽  
Light Sensitivity ◽  
Cgmp Level ◽  
Volvox Carteri ◽  
Non Invasive ◽  
Cgmp Signaling ◽  
Membrane Bound ◽  
Light Flashes

Abstract Background Microbial rhodopsins vary in their chemical properties, from light sensitive ion transport to different enzymatic activities. Recently, a novel family of two-component Cyclase (rhod)opsins (2c-Cyclop) from the green algae Chlamydomonas reinhardtii and Volvox carteri was characterized, revealing a light-inhibited guanylyl cyclase (GC) activity. More genes similar to 2c-Cyclop exist in algal genomes, but their molecular and physiological functions remained uncharacterized. Results Chlamyopsin-5 (Cop5) from C. reinhardtii is related to Cr2c-Cyclop1 (Cop6) and can be expressed in Xenopus laevis oocytes, but shows no GC activity. Here, we exchanged parts of Cop5 with the corresponding ones of Cr2c-Cyclop1. When exchanging the opsin part of Cr2c-Cyclop1 with that of Cop5, we obtained a bi-stable guanylyl cyclase (switch-Cyclop1) whose activity can be switched by short light flashes. The GC activity of switch-Cyclop1 is increased for hours by a short 380 nm illumination and switched off (20-fold decreased) by blue or green light. switch-Cyclop1 is very light-sensitive and can half-maximally be activated by ~ 150 photons/nm2 of 380 nm (~ 73 J/m2) or inhibited by ~ 40 photons/nm2 of 473 nm (~ 18 J/m2). Conclusions This engineered guanylyl cyclase is the first light-switchable enzyme for cGMP level regulation. Light-regulated cGMP production with high light-sensitivity is a promising technique for the non-invasive investigation of the effects of cGMP signaling in many different tissues.

scholarly journals Nitric Oxide Activates the β2Subunit of Soluble Guanylyl Cyclase in the Absence of a Second Subunit

2001 ◽  
Vol 276 (33) ◽  
pp. 30737-30743 ◽  
Author(s):  
Markus Koglin ◽  
Kai Vehse ◽  
Lars Budaeus ◽  
Hasso Scholz ◽  
Sönke Behrends
Keyword(s):  
Nitric Oxide ◽  
Guanylyl Cyclase ◽  
Soluble Guanylyl Cyclase
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