The role of the adenylate cyclase (Ac)-cAMP system in mediating deoxycholic acid (DOC)-induced fluid secretion was studied in the rat jejunum and colon in vivo using the AC inhibitor, RMI 12 330 A. A potent inhibitory effect of RMI 12 330 A on fluid secretion induced by cholera toxin was demonstrated in ligated rat jejunal loops. On the contrary, the changes of fluid movement in jejunal and colonic loops caused by DOC could not be influenced by RMI 12 330 A, and mucosal cAMP levels of colonic loops were not increased. Colonic mucosal permeability estimated by the 14C-erythritol clearance increased significantly during a 45-min exposure to 3 mmol DOC, and was not affected by RMI 12 330 A. These results do not support the theory that the AC-cAMP system plays an important role in DOC-induced intestinal fluid secretion and suggest that an increase in mucosal permeability is the predominant factor responsible for the secretagogue effect.
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http://dx.doi.org/10.1159/000198982 | DOI Listing |
Vaccines (Basel)
December 2023
Hospital Universitari Germans Trias i Pujol, 08916 Badalona, Spain.
Phys Med Biol
August 2017
Département de physique, de génie physique et d'optique et Centre de recherche sur le cancer, Université Laval, Québec, Canada. Département de radio-oncologie et CRCHU de Québec, CHU de Québec, QC, Canada. Department of Radiation Oncology, Francis H. Burr Proton Therapy Center Massachusetts General Hospital (MGH), Boston, MA, United States of America.
The relative stopping power (RSP) uncertainty is the largest contributor to the range uncertainty in proton therapy. The purpose of this work was to develop a systematic method that yields accurate and patient-specific RSPs by combining (1) pre-treatment x-ray CT and (2) daily proton radiography of the patient. The method was formulated as a penalized least squares optimization problem (argmin([Formula: see text])).
View Article and Find Full Text PDFAuton Neurosci
March 2009
Department of Internal Medicine, College of Medicine, Hanyang University, 17 Haengdang-Dong, Sungdong-Ku, Seoul 133-791, Republic of Korea.
In this experiment, we examined the influence of the posterior hypothalamic adenosine A(2A) receptors on the central cardiovascular regulation of blood pressure (BP) and heart rate (HR). Posterior hypothalamic injection of drugs was performed in anesthetized, artificially ventilated male Sprague-Dawley rats. Injection of CGS-21680HCl (CGS; 20 nmol), an adenosine A(2A) receptor agonist, elicited a decrease of arterial BP and HR, while injection of 8-(3-Chlorostyryl)caffeine (CSC; 10 nmol), an adenosine A(2A) receptor antagonist, blocked the depressor and bradycardiac effects of CGS (20 nmol).
View Article and Find Full Text PDFAuton Neurosci
July 2007
Department of Pharmacology, College of Medicine, Hanyang University, 17 Haengdang-Dong, Sungdong-Ku, Seoul 133-791, Republic of Korea.
Cardiovascular inhibitory effects induced by the posterior hypothalamic adenosine A(2) receptors were suggested by our previous reports. In this experiment, we examined the influence of the posterior hypothalamic adenosine A(2B) receptors on central cardiovascular regulation of blood pressure (BP) and heart rate (HR). Posterior hypothalamic injection of drugs was performed in anesthetized, artificially ventilated male Sprague-Dawley rats.
View Article and Find Full Text PDFNeurosci Lett
October 2000
Department of Pharmacology, College of Medicine, Hanyang University, Seoul, South Korea.
This study was performed to investigate the influence of spinal adenosine A2 receptors on the central regulation of blood pressure (BP) and heart rate (HR), and to define whether its mechanism is mediated by adenylate cyclase or guanylate cyclase. Intrathecal (i.t.
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