Effects of Hyperhomocysteinemia on Non-Adrenergic Non-Cholinergic Relaxation in Isolated Rat Duodenum

Karasu, Edibe; Sadan, Gulay; Taşatargil, Arda

doi:10.1007/s10620-008-0318-7

Cited by 4 publications

(1 citation statement)

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“…The gastrointestinal tract accounts for 25% of whole body transmethylation and transsulfuration pathways and is a prominent site of net Hcy release [15]. As reported previously, Hcy has been shown to change intestinal motility, in both a procinetic and inhibitory pattern, acting by modulation of nitrergic innervation or by potassium channels [26,39]. The present study was undertaken to expand upon those initial fi ndings and to assess the effect of D,L-homocysteine on the duodenal motility, especially mechanisms involving nitrergic and cholinergic pathways.…”

Section: Discussionmentioning

confidence: 83%

Different pathways involved in the stimulatory effects of homocysteine on rat duodenal smooth muscle

et al. 2017

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Recent studies have confi rmed that hyperhomocysteinemia is associated with gastrointestinal diseases; however, the direct effect of homocysteine on gastrointestinal reactivity still remains unknown. The aim of this study was to demonstrate how homocysteine may affect nitric oxide mediated duodenal relaxation and whether cholinergic receptors and K + channels take part in stimulating motility, as well as to explore whether oxidative stress is associated with homocysteine-mediated effects. Experiments were carried out on male rats, body mass 250-300 g. Two groups of animals were treated by i.p. application of saline and D,L-Hcy (0.6 μmol/g bm). After 2h of incubation, the duodenal segments were prepared for biochemical analysis and contractile response measurements in an organ bath with Tyrode's solution. Effects of TEA (10 mmol/L) and L-NAME (30 μmol/L) on duodenal contractility in the presence of D,L-Hcy (0.6 μmol/g bm) were investigated. Elevated homocysteine levels seem to be of crucial importance for the deterioration of contractility through nitric oxide mediated relaxation, and, in part, by activation of K + channels. Hcy showed direct promuscarinic effects, since 30 min pretreatment of rat duodenum signifi cantly enhanced the contractile effect of increasing concentrations of ACh (10 -9 -10 -2 mol/L). Catalase activity, superoxide dismutase, glutathione peroxidase and the total antioxidant system were reduced while the thiobarbituric acid-reactive substances level was elevated. Our data showed a consistent profi le of gastrointestinal injury elicited by sulfur-containing amino acid-homocysteine. This could contribute to explain, at least in part, the mechanisms involved in human gastrointestinal diseases associated to hyperhomocysteinemia.

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Section: Discussionmentioning

confidence: 83%