Role of Cyclic Nucleotides in the Effect of Hydrogen Sulfide on Contractions of Rat Jejunum

© 2017 Springer Science+Business Media, LLCWe studied the role of cyclic nucleotides in the influence of hydrogen sulfide (H2S) donor, sodium hydrosulfide (NaHS, 200 μM), on motor activity of rat jejunum. NaHS reduced spontaneous and carbachol-induced contractions of rat jejunum segment, which suggests that H2S can act through mechanisms involving muscarinic receptor activation. Against the background of a membrane-penetrating non-hydrolyzable cAMP analogue or under conditions of adenylate cyclase blockade, the inhibitory effect of NaHS on the carbachol-induced contractions was maintained. Against the background of elevated cGMP concentration or guanylate cyclase inhibition, the reduction of carbachol-induced contractions upon exposure to NaHS was less pronounced than in control. It was hypothesized that H2S induces relaxation of carbachol-induced jejunum contractions, affecting protein kinase G targets or activating cGMP synthesis

Role of Cyclic Nucleotides in the Effect of Hydrogen Sulfide on Contractions of Rat Jejunum

© 2017 Springer Science+Business Media, LLCWe studied the role of cyclic nucleotides in the influence of hydrogen sulfide (H2S) donor, sodium hydrosulfide (NaHS, 200 μM), on motor activity of rat jejunum. NaHS reduced spontaneous and carbachol-induced contractions of rat jejunum segment, which suggests that H2S can act through mechanisms involving muscarinic receptor activation. Against the background of a membrane-penetrating non-hydrolyzable cAMP analogue or under conditions of adenylate cyclase blockade, the inhibitory effect of NaHS on the carbachol-induced contractions was maintained. Against the background of elevated cGMP concentration or guanylate cyclase inhibition, the reduction of carbachol-induced contractions upon exposure to NaHS was less pronounced than in control. It was hypothesized that H2S induces relaxation of carbachol-induced jejunum contractions, affecting protein kinase G targets or activating cGMP synthesis

Role of Cyclic Nucleotides in the Effect of Hydrogen Sulfide on Contractions of Rat Jejunum

© 2017 Springer Science+Business Media, LLCWe studied the role of cyclic nucleotides in the influence of hydrogen sulfide (H2S) donor, sodium hydrosulfide (NaHS, 200 μM), on motor activity of rat jejunum. NaHS reduced spontaneous and carbachol-induced contractions of rat jejunum segment, which suggests that H2S can act through mechanisms involving muscarinic receptor activation. Against the background of a membrane-penetrating non-hydrolyzable cAMP analogue or under conditions of adenylate cyclase blockade, the inhibitory effect of NaHS on the carbachol-induced contractions was maintained. Against the background of elevated cGMP concentration or guanylate cyclase inhibition, the reduction of carbachol-induced contractions upon exposure to NaHS was less pronounced than in control. It was hypothesized that H2S induces relaxation of carbachol-induced jejunum contractions, affecting protein kinase G targets or activating cGMP synthesis

Role of Cyclic Nucleotides in the Effect of Hydrogen Sulfide on Contractions of Rat Jejunum

© 2017 Springer Science+Business Media, LLCWe studied the role of cyclic nucleotides in the influence of hydrogen sulfide (H2S) donor, sodium hydrosulfide (NaHS, 200 μM), on motor activity of rat jejunum. NaHS reduced spontaneous and carbachol-induced contractions of rat jejunum segment, which suggests that H2S can act through mechanisms involving muscarinic receptor activation. Against the background of a membrane-penetrating non-hydrolyzable cAMP analogue or under conditions of adenylate cyclase blockade, the inhibitory effect of NaHS on the carbachol-induced contractions was maintained. Against the background of elevated cGMP concentration or guanylate cyclase inhibition, the reduction of carbachol-induced contractions upon exposure to NaHS was less pronounced than in control. It was hypothesized that H2S induces relaxation of carbachol-induced jejunum contractions, affecting protein kinase G targets or activating cGMP synthesis

Role of Cyclic Nucleotides in the Effect of Hydrogen Sulfide on Contractions of Rat Jejunum

© 2017 Springer Science+Business Media, LLCWe studied the role of cyclic nucleotides in the influence of hydrogen sulfide (H2S) donor, sodium hydrosulfide (NaHS, 200 μM), on motor activity of rat jejunum. NaHS reduced spontaneous and carbachol-induced contractions of rat jejunum segment, which suggests that H2S can act through mechanisms involving muscarinic receptor activation. Against the background of a membrane-penetrating non-hydrolyzable cAMP analogue or under conditions of adenylate cyclase blockade, the inhibitory effect of NaHS on the carbachol-induced contractions was maintained. Against the background of elevated cGMP concentration or guanylate cyclase inhibition, the reduction of carbachol-induced contractions upon exposure to NaHS was less pronounced than in control. It was hypothesized that H2S induces relaxation of carbachol-induced jejunum contractions, affecting protein kinase G targets or activating cGMP synthesis

Characterization of gut contractility and microbiota in patients with severe chronic constipation.

Chronic constipation (CC) is one of the most common gastrointestinal disorders worldwide. Its pathogenesis, however, remains largely unclear. The purpose of the present work was to gain an insight into the role of contractility and microbiota in the etiology of CC. To this end, we studied spontaneous and evoked contractile activity of descending colon segments from patients that have undergone surgery for refractory forms of CC. The juxta-mucosal microbiota of these colon samples were characterized with culture-based and 16S rRNA sequencing techniques. In patients with CC the spontaneous colonic motility remained unchanged compared to the control group without dysfunction of intestinal motility. Moreover, contractions induced by potassium chloride and carbachol were increased in both circular and longitudinal colonic muscle strips, thus indicating preservation of contractile apparatus and increased sensitivity to cholinergic nerve stimulation in the constipated intestine. In the test group, the gut microbiota composition was assessed as being typically human, with four dominant bacterial phyla, namely Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria, as well as usual representation of the most prevalent gut bacterial genera. Yet, significant inter-individual differences were revealed. The phylogenetic diversity of gut microbiota was not affected by age, sex, or colonic anatomy (dolichocolon, megacolon). The abundance of butyrate-producing genera Roseburia, Coprococcus, and Faecalibacterium was low, whereas conventional probiotic genera Lactobacillus and Bifidobacteria were not decreased in the gut microbiomes of the constipated patients. As evidenced by our study, specific microbial biomarkers for constipation state are absent. The results point to a probable role played by the overall gut microbiota at the functional level. To our knowledge, this is the first comprehensive characterization of CC pathogenesis, finding lack of disruption of motor activity of colonic smooth muscle cells and insufficiency of particular members of gut microbiota usually implicated in CC