American journal of physiology. Regulatory, integrative and comparative physiology
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Am. J. Physiol. Regul. Integr. Comp. Physiol. · Jan 2009
Increased renal adrenomedullin expression in rats with ureteral obstruction.
Ureteral obstruction is characterized by decreased renal blood flow that is associated with hypoxia within the kidney. Adrenomedullin (AM) is a peptide hormone with tissue-protective capacity that is stimulated through hypoxia. We tested the hypothesis that ureteral obstruction stimulates expression of AM and hypoxia-inducible factor-1 (HIF-1alpha) in kidneys. ⋯ HIF-1alpha protein abundance increased significantly in IM after 24-h BUO compared with Sham and HIF-1alpha immunoreactive protein colocalized with AM. In summary, AM and HIF-1alpha expression increases in response to ureteral obstruction in agreement with expected oxygen gradients. Hypoxia acting through HIF-1alpha accumulation may be an important pathway for the renal response to ureteral obstruction.
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Am. J. Physiol. Regul. Integr. Comp. Physiol. · Jan 2009
Inhibitory effects and mechanisms of intestinal electrical stimulation on gastric tone, antral contractions, pyloric tone, and gastric emptying in dogs.
The aim of this study was to investigate the effects and mechanisms of intestinal electrical stimulation (IES) on gastric tone, antral and pyloric contractions, and gastric emptying in dogs. Female hound dogs were equipped with a duodenal or gastric cannula, and one pair of serosal electrodes was implanted in the small intestine. The study consisted of five different experiments. ⋯ IES alone did not affect pyloric tone or resistance, but IES + l-NNA decreased pyloric tone. In conclusion, IES reduces gastric tone via the nitrergic pathway, inhibits antral contractions via the adrenergic pathway, does not affect pyloric tone, and delays liquid gastric emptying. IES-induced delay of gastric emptying is attributed to its inhibitory effects on gastric motility.