Many orally administered phenolic drugs undergo enterohepatic recycling (EHR), presumably mediated by the hepatic phase II enzymes. However, the disposition of extrahepatically generated phase II metabolites is unclear. This paper aims to determine the new roles of liver and intestine in the disposition of oral phenolics. Sixteen representative phenolics were tested using direct portal vein infusion and/or intestinal perfusion. The results showed that certain glucuronides were efficiently recycled by liver. OATP1B1/1B3/2B1 were the responsible uptake transporters. Hepatic uptake is the rate-limiting step in hepatic recycling. Our findings showed that the disposition of many oral phenolics is mediated by intestinal glucuronidation and hepatic recycling. A new disposition mechanism 'Hepatoenteric Recycling (HER)", where intestine is the metabolic organ and liver is the recycling organ, was revealed. Further investigations focusing on HER should help interpret how intestinal aliments or co-administered drugs that alter gut enzymes (e.g. UGTs) expression/activities will impact the disposition of phenolics.
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http://dx.doi.org/10.7554/eLife.58820 | DOI Listing |
Basic Clin Pharmacol Toxicol
January 2025
Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland.
Raloxifene has low bioavailability due to extensive glucuronidation in the intestine and the liver, and its pharmacokinetics is associated with high intra- and interindividual variability. Some of this variability could be explained by the enterohepatic recycling of raloxifene, which is driven by transporter-mediated uptake and efflux and gut microbial deglucuronidation of raloxifene glucuronides. These individual processes involved in raloxifene disposition, however, have not been characterized in full detail.
View Article and Find Full Text PDFMetabolites
August 2024
Department of Pharmaceutical Sciences, Temple University School of Pharmacy, Philadelphia, PA 19130, USA.
MAbs
July 2024
Department of Biologics, Amgen Research, Amgen Inc, South San Francisco, CA, USA.
Targeting antigens with antibodies exhibiting pH/Ca-dependent binding against an antigen is an attractive strategy to mitigate target-mediated disposition and antigen buffering. Studies have reported improved serum exposure of antibodies exhibiting pH/Ca-binding against membrane-bound receptors. Asialoglycoprotein receptor 1 (ASGR1) is a membrane-bound receptor primarily localized in hepatocytes.
View Article and Find Full Text PDFAm J Physiol Cell Physiol
May 2023
Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States.
A primary function of intercalated cells in the distal tubule of the kidney is to maintain pH homeostasis. For example, type B intercalated cells secrete bicarbonate largely through the action of the apical Cl/HCO exchanger, pendrin, which helps correct metabolic alkalosis. Since both the K-Cl cotransporter, KCC3a and pendrin colocalize to the apical region of type B and non-A, non-B intercalated cells and since both are upregulated in models of metabolic alkalosis, such as with dietary NaHCO loading, we raised the possibility that apical KCC3a facilitates pendrin-mediated bicarbonate secretion, such as through apical Cl recycling.
View Article and Find Full Text PDFCyberpsychol Behav Soc Netw
April 2023
Department of Psychology, Research Center in Communication Psychology, Università Cattolica del Sacro Cuore, Milan, Italy.
Virtual nature exposure has emerged as an effective method for promoting pro-environmental attitudes and behaviors, also due to the increased emotional connection with nature itself. However, the role played by complex emotions elicited by virtual nature, such as awe, needs to be fully elucidated. Awe is an emotion stemming from vast stimuli, including nature, and virtual reality (VR) emerged as an effective medium to elicit it.
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