scholarly journals Effect of N6, 2’-O-Dibutyryl 3’5’-Cyclic Adenosine Monophosphate, 3’, 5’,-Cyclic Adenosine Monophosphate and Adenosine Triphosphate on Acetylcholine Output from Cholinergic Nerves in Guinea Pig Ileum

1972 ◽  
Vol 22 (1) ◽  
pp. 33-36
Author(s):  
Keijiro TAKAGI ◽  
Issei TAKAYANAGI
2019 ◽  
Vol 18 (1) ◽  
pp. 34-38
Author(s):  
Chen Lei ◽  
Pan Xiang ◽  
Shen Yonggang ◽  
Song Kai ◽  
Zhong Xingguo ◽  
...  

The aim of this study was to determine whether polydatin, a glucoside of resveratrol isolated from the root of Polygonum cuspidatum, warranted development as a potential therapeutic for ameliorating the pain originating from gallbladder spasm disorders and the underlying mechanisms. Guinea pig gallbladder smooth muscles were treated with polydatin and specific inhibitors to explore the mechanisms underpinning polydatin-induced relaxation of carbachol-precontracted guinea pig gallbladder. Our results shown that polydatin relaxed carbachol-induced contraction in a dose-dependent manner through the nitric oxide/cyclic guanosine monophosphate/protein kinase G and the cyclic adenosine monophosphate/protein kinase A signaling pathways as well as the myosin light chain kinase and potassium channels. Our findings suggested that there was value in further exploring the potential therapeutic use of polydatin in gallbladder spasm disorders.


1986 ◽  
Vol 61 (3) ◽  
pp. 1025-1030 ◽  
Author(s):  
J. G. Martin ◽  
B. Collier

We measured acetylcholine (ACh) release from canine isolated tracheal smooth muscle (TSM) and bronchial spirals using a radioenzymic assay technique. Tissue was incubated in physiological salt solution containing physostigmine (3.10(-5) M), atropine (10(-7) M), and choline (5.10(-6) M), and bath fluid was collected every 15 min for assay. There was a resting release of ACh of 209 +/- 44 pmol/g tissue (mean +/- SE) from 53 to 77 specimens of TSM. Electrical field stimulation (ES) increased ACh release, which was blocked by tetrodotoxin (10(-6) g/ml), confirming the neural origin of ACh. The ACh output during ES (2-ms pulses) at 10 Hz increased linearly from 188 +/- 50 pmol/g tissue (mean +/- SE) for a 1-min volley, to 323 +/- 57 for three volleys, and 544 +/- 128 for five volleys. The ACh output/pulse was constant during ES at 20, 15, 10, and 5 Hz, but it was significantly higher at 2 than at 5 Hz (P less than 0.005). Incubation of TSM with norepinephrine (NE, 10(-5) M) did not affect ACh output either at 2 or 10 Hz. Likewise, ACh output from bronchial spirals during ES and 2 Hz was unaffected by NE. In contrast, NE treatment of isolated guinea pig ileum reduced the ACh released by ES at 2 Hz to 40 +/- 7% (P less than 0.001) of the control ACh output. It is concluded that evoked release of ACh (output/pulse) from cholinergic nerves in canine airway is frequency dependent, as in guinea pig ileum, but that, unlike guinea pig ileum, NE does not modulate its release.


2019 ◽  
Vol 6 (12) ◽  
pp. 3684-3698 ◽  
Author(s):  
Pavel Janoš ◽  
Jakub Ederer ◽  
Marek Došek ◽  
Jiří Štojdl ◽  
Jiří Henych ◽  
...  

Nanoceria accelerates dramatically not only the dephosphorylation of energetically rich biomolecules such as adenosine triphosphate (ATP), but also the cleavage of highly resistant phosphodiester bonds in 3′,5′-cyclic adenosine monophosphate (cAMP).


2020 ◽  
Author(s):  
Alexander Nemukhin ◽  
Maria Khrenova ◽  
Anna M. Kulakova

<p>We report the first computational characterization of an optogenetic system composed of two photosensing BLUF (<u>b</u>lue <u>l</u>ight sensor <u>u</u>sing <u>f</u>lavin adenine dinucleotide) domains and two catalytic adenylyl cyclase (AC) domains. Conversion of adenosine triphosphate (ATP) to cyclic adenosine monophosphate (cAMP) and pyrophosphate (PPi) catalyzed by ACs coupled with excitation in photosensing domains has emerged in the focus of modern optogenetic applications because of the request in photoregulated enzymes to modulate cellular concentrations of signaling messengers. The photoactivated adenylyl cyclase from the soil bacterium <i>Beggiatoa sp.</i> (bPAC) is an important model showing considerable increase of the ATP to cAMP conversion rate in the catalytic domain after the illumination of the BLUF domain. The 1 μs classical molecular dynamics simulations reveal that the activation of the BLUF domain leading to tautomerization of Gln49 in the chromophore binding pocket results in switching of position of the side chain of Arg278 in the active site of AC. Allosteric signal transmission pathways between Gln49 from BLUF and Arg278 from AC were revealed by the dynamical network analysis. The Gibbs energy profiles of the ATP → cAMP + PPi reaction computed using QM(DFT(ωB97X-D3/6-31G**))/MM(CHARMM) molecular dynamics simulations for both Arg278 conformations in AC clarify the reaction mechanism. In the light-activated system, the corresponding arginine conformation stabilizes the pentacoordinated phosphorus of the α-phosphate group in the transition state, thus lowering the activation energy. Simulations of the bPAC system with the Tyr7Phe replacement in BLUF demonstrate occurrence of both arginine conformations in an equal ratio, explaining the experimentally observed intermediate catalytic activity of the bPAC-Y7F variant as compared with the dark and light states of the wild type bPAC. </p>


Sign in / Sign up

Export Citation Format

Share Document