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- Henriksnäs, Johanna, et al.
(författare)
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Acute effects of Helicobacter pylori extracts on gastric mucosal blood flow in the mouse
- 2009
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Ingår i: World Journal of Gastroenterology. - : Baishideng Publishing Group Inc.. - 1007-9327 .- 2219-2840. ; 15:2, s. 219-225
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Tidskriftsartikel (refereegranskat)abstract
- AIM: To investigate the mechanisms underlying the reduction in gastric blood flow induced by a luminal water extract of Helicobacter pylori (HPE).METHODS: The stomachs of isoflurane-anesthetized mice were exteriorized, and the mucosal surface exposed. Blood flow was measured with the laser-Doppler technique, and systemic arterial blood pressure monitored. C57BL/6 mice were exposed to water extract produced from H pylori strain 88-23. To investigate the role of a nerve- or iNOS-mediated pathway, we used intraluminal lidocaine and iNOS-/- mice. Blood flow response to the endogenous nitric oxide synthase inhibitor asymmetric dimethyl arginine (ADMA) was also assessed.RESULTS: In wild-type mice, HPE decreased mucosal blood flow by approximately 30%. This reduction was abolished in iNOS-deficient mice, and by pre-treatment with lidocaine. Luminally applied ADMA resulted in reduction in blood flow similar to that observed in wild-type mice exposed to HPE.CONCLUSION: A H pylori water extract reduces gastric mucosal blood flow acutely through iNOS- and nerve-mediated pathways.
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| 2. |
- Shore, Richard, et al.
(författare)
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Sex differences and effects of oestrogen in rat gastric mucosal defence
- 2017
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Ingår i: World Journal of Gastroenterology. - : Baishideng Publishing Group Inc.. - 1007-9327 .- 2219-2840. ; 23:3, s. 426-436
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Tidskriftsartikel (refereegranskat)abstract
- AIM To evaluate sex differences and the effects of oestrogen administration in rat gastric mucosal defence. METHODS Sex differences in gastric mucus thickness and accumulation rate, absolute gastric mucosal blood flow using microspheres, the integrity of the gastric mucosal epithelium in response to a chemical irritant and the effects of oestrogen administration on relative gastric mucosal blood flow in an acute setting was assessed in an in vivo rat experimental model. Subsequently, sex differences in the distribution of oestrogen receptors and calcitonin gene related peptide in the gastric mucosa of animals exposed to oestrogen in the above experiments was evaluated using immunohistochemistry. RESULTS The absolute blood flow in the GI-tract was generally higher in males, but only significantly different in the corpus part of the stomach (1.12 +/- 0.12 mL/min.g in males and 0.51 +/- 0.03 mL/min.g in females) (P = 0.002). After removal of the loosely adherent mucus layer the thickness of the firmly adherent mucus layer in males and females was 79 +/- 1 mu m and 80 +/- 3 mu m respectively. After 60 min the mucus thickness increased to 113 +/- 3 mu m in males and 121 +/- 3 mu m in females with no statistically significant difference seen between the sexes. Following oestrogen administration (0.1 followed by 1 mu g/kg.min), mean blood flow in the gastric mucosa decreased by 31% [68 +/- 13 perfusion units (PFU)] in males which was significantly different compared to baseline (P = 0.02). In females however, mean blood flow remained largely unchanged with a 4% (5 +/- 33 PFU) reduction. The permeability of the gastric mucosa increased to a higher level in females than in males (P = 0.01) after taurocholate challenge. However, the calculated mean clearance increase did not significantly differ between the sexes [0.1 +/- 0.04 to 1.1 +/- 0.1 mL/min.100 g in males and 0.4 +/- 0.3 to 2.1 +/- 0.3 mL/min.100 g in females (P = 0.065)]. There were no significant differences between 17 beta-Estradiol treated males (mean ratio of positive staining +/- SEM) (0.06 +/- 0.07) and females (0.11 +/- 0.11) in the staining of ER alpha (P = 0.24). Also, there were no significant differences between 17 beta-Estradiol treated males (0.18 +/- 0.21) and females (0.06 +/- 0.12) in the staining of ER beta (P = 0.11). Finally, there were no significant differences between 17 beta-Estradiol treated males (0.04 +/- 0.05) and females (0.11 +/- 0.10) in the staining of CGRP (P = 0.14). CONCLUSION Gastric mucosal blood flow is higher in male than in female rats and is reduced in male rats by oestrogen administration.
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