Inhibition of Escherichia coli heat-stable enterotoxin by indomethacin and chlorpromazine

1980 ◽  
Vol 29 (3) ◽  
pp. 908-913
Author(s):  
R N Greenberg ◽  
F Murad ◽  
B Chang ◽  
D C Robertson ◽  
R L Guerrant
Keyword(s):  
Escherichia Coli ◽  
Guanylate Cyclase ◽  
Fluid Secretion ◽  
Cyclic Guanosine Monophosphate ◽  
Guanosine Monophosphate ◽  
Enterotoxigenic Escherichia Coli ◽  
Fluid Accumulation ◽  
Intestinal Tissue ◽  
Suckling Mice ◽  
Heat Stable

Purified heat-stable enterotoxin (ST) from a procine strain of enterotoxigenic Escherichia coli activates quanylate cyclase in particulate fractions of rat intestinal tissue and induces fluid accumulation in suckling mice. These effects of ST were examined in the presence of either indomethacin or chlorpromazine. We also examined the effects of these two drugs on fluid accumulation in suckling mice induced by the 8-bromo analog of cyclic guanosine monophosphate. Either indomethacin or chlorpromazine reduced ST activation of guanylate cyclase. Both drugs also reduced intestinal fluid accumulation in suckling mice that resulted from submaximal doses of ST (both P < 0.001). However, there was no reduction in fluid secretion by either drug when a maximally effective dose of ST was used, suggesting that inhibition of fluid secretion by both drugs can be overcome by increasing the ST dose and that a threshold level of guanylate cyclase activity results in maximal secretory response. Both drugs also reduced basal guanylate cylase activity in rat intestinal tissue and fluid secreton in suckling mice. Chlorpromazine also reduced intestinal secretion mediated by 8-bromo cyclic guanosine monophosphate (P < 0.001). These findings indicate that chlorpromazine interferes with the effects of ST both before and after its activation of guanylate cyclase, whereas indomethacin interfers with ST only before its activation of guanylate cyclase.

Expression of a truncated guanylate cyclase (GC-C), a receptor for heat-stable enterotoxin of enterotoxigenic Escherichia coli, and its dimer formation in COS-7 cells

1993 ◽  
Vol 15 (4) ◽  
pp. 283-291 ◽  
Author(s):  
Toshiya Hirayama ◽  
Akihiro Wada ◽  
Yuji Hidaka ◽  
Jun-ichi Fujisawa ◽  
Yoshifumi Takeda ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Guanylate Cyclase ◽  
Enterotoxigenic Escherichia Coli ◽  
Dimer Formation ◽  
Heat Stable

Inhibition of Escherichia coli heat-stable enterotoxin effects on intestinal guanylate cyclase and fluid secretion by quinacrine

1982 ◽  
Vol 31 (11) ◽  
pp. 2005-2009 ◽  
Author(s):  
Richard N. Greenberg ◽  
Richard L. Guerrant ◽  
Chang Bing ◽  
Donald C. Robertson ◽  
Ferid Murad
Keyword(s):  
Escherichia Coli ◽  
Guanylate Cyclase ◽  
Fluid Secretion ◽  
Heat Stable

Soluble Guanylate Cyclase Stimulators and Activators: Where are We and Where to Go?

2019 ◽  
Vol 19 (18) ◽  
pp. 1544-1557 ◽  
Author(s):  
Sijia Xiao ◽  
Qianbin Li ◽  
Liqing Hu ◽  
Zutao Yu ◽  
Jie Yang ◽  
...  
Keyword(s):  
Guanylate Cyclase ◽  
Soluble Guanylate Cyclase ◽  
Muscle Relaxation ◽  
Cyclic Guanosine Monophosphate ◽  
Guanosine Monophosphate ◽  
Smooth Muscle Relaxation ◽  
Secondary Messenger ◽  
Physiological Processes ◽  
Cgmp Pathway ◽  
Preclinical And Clinical Studies

Soluble Guanylate Cyclase (sGC) is the intracellular receptor of Nitric Oxide (NO). The activation of sGC results in the conversion of Guanosine Triphosphate (GTP) to the secondary messenger cyclic Guanosine Monophosphate (cGMP). cGMP modulates a series of downstream cascades through activating a variety of effectors, such as Phosphodiesterase (PDE), Protein Kinase G (PKG) and Cyclic Nucleotide-Gated Ion Channels (CNG). NO-sGC-cGMP pathway plays significant roles in various physiological processes, including platelet aggregation, smooth muscle relaxation and neurotransmitter delivery. With the approval of an sGC stimulator Riociguat for the treatment of Pulmonary Arterial Hypertension (PAH), the enthusiasm in the discovery of sGC modulators continues for broad clinical applications. Notably, through activating the NO-sGC-cGMP pathway, sGC stimulator and activator potentiate for the treatment of various diseases, such as PAH, Heart Failure (HF), Diabetic Nephropathy (DN), Systemic Sclerosis (SS), fibrosis as well as other diseases including Sickle Cell Disease (SCD) and Central Nervous System (CNS) disease. Here, we review the preclinical and clinical studies of sGC stimulator and activator in recent years and prospect for the development of sGC modulators in the near future.

scholarly journals Current Modulation of Guanylate Cyclase Pathway Activity—Mechanism and Clinical Implications

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3418
Author(s):  
Grzegorz Grześk ◽  
Alicja Nowaczyk
Keyword(s):  
Guanylate Cyclase ◽  
Natriuretic Peptides ◽  
Soluble Guanylate Cyclase ◽  
Cyclic Guanosine Monophosphate ◽  
Guanosine Monophosphate ◽  
Pharmacological Intervention ◽  
First Line ◽  
Phosphodiesterase Type ◽  
Activity Mechanism

For years, guanylate cyclase seemed to be homogenic and tissue nonspecific enzyme; however, in the last few years, in light of preclinical and clinical trials, it became an interesting target for pharmacological intervention. There are several possible options leading to an increase in cyclic guanosine monophosphate concentrations. The first one is related to the uses of analogues of natriuretic peptides. The second is related to increasing levels of natriuretic peptides by the inhibition of degradation. The third leads to an increase in cyclic guanosine monophosphate concentration by the inhibition of its degradation by the inhibition of phosphodiesterase type 5. The last option involves increasing the concentration of cyclic guanosine monophosphate by the additional direct activation of soluble guanylate cyclase. Treatment based on the modulation of guanylate cyclase function is one of the most promising technologies in pharmacology. Pharmacological intervention is stable, effective and safe. Especially interesting is the role of stimulators and activators of soluble guanylate cyclase, which are able to increase the enzymatic activity to generate cyclic guanosine monophosphate independently of nitric oxide. Moreover, most of these agents are effective in chronic treatment in heart failure patients and pulmonary hypertension, and have potential to be a first line option.

Use of a Multiplex PCR System for the Simultaneous Detection of Heat Labile Toxin I and Heat Stable Toxin II Genes of Enterotoxigenic Escherichia coli in Skim Milk and Porcine Stool

1998 ◽  
Vol 61 (2) ◽  
pp. 141-145 ◽  
Author(s):  
HAU-YANG TSEN ◽  
LIANG-ZHAO JIAN ◽  
WAN-RONG CHI
Keyword(s):  
Escherichia Coli ◽  
Multiplex Pcr ◽  
Simultaneous Detection ◽  
Skim Milk ◽  
Pcr Primers ◽  
Enterotoxigenic Escherichia Coli ◽  
Farm Animals ◽  
Target Cells ◽  
Heat Stable ◽  
Heat Labile

Enterotoxigenic Escherichia coli (ETEC) strains which produce heat labile and/or heat stable toxins (LT and ST) may cause diarrhea in humans and farm animals. Using PCR primers specific for the LT I and ST II genes, a multiplex PCR system which allows detection of LT I- and ST II-producing ETEC strains was developed. When skim milk was used for a PCR assay, it was found that if target cells in the sample were precultured in MacConkey broth for 8 h prior to PCR as few as 100 cells per ml of the sample could be detected. Without the preculture step, 104 CFU of target cells per 0.2 g of porcine stool specimen were required to generate visible PCR products. The multiplex PCR System can be used for rapid testing of fecal specimens, food and possibly environmental samples for the presence of ETEC strains.

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