20.500.12556/DiRROS-15046 Early biomarkers of altered renal function and orthostatic intolerance during 10-day bedrest Exposure to actual or simulated microgravity results in alterations of renal function, fluid redistribution, and bone loss, which is coupled to a rise of urinary calcium excretion. We provided evidence that high calcium delivery to the collecting duct reduces local Aquaporin 2 (AQP2)-mediated water reabsorption under vasopressin action, thus limiting the maximal urinary concentration to reduce calcium saturation. To investigate early renal adaptation into simulated microgravity, we investigated the effects of 10 days of strict bedrest in 10 healthy volunteers. We report here that 10 days of inactivity are associated with a transient, significant decrease (day 5) in vasopressin (copeptin) paralleled by a decrease in AQP2 excretion, consistent with an increased central volume to the heart, resulting in reduced water reabsorption. Moreover, bedrest caused a significant increase in calciuria secondary to bone demineralization paralleled by a decrease in PTH. Urinary osteopontin, a glycoprotein exerting a protective effect on stone formation, was significantly reduced during bedrest. Moreover, a significant increase in adrenomedullin (day 5), a peptide with vasodepressor properties, was observed at day 5, which may contribute to the known reduced orthostatic capacity post-bedrest. We conclude that renal function is altered in simulated microgravity and is associated with an early increase in the risk of stone formation and reduced orthostatic capacity post-bedrest within a few days of inactivity. kidney functions bed rest biomarkers orthostatic intolerance vasopressin copeptin aquaporin-2 adrenomedullin calcium ledvice delovanje ležanje v postelji biomarkerji ortostatska intoleranca vazopresin kopeptin akvaporin-2 osteopontin adrenomedulin kalcij true false true Angleški jezik Ni določen © 2022 Tamma, Di Mise, Ranieri, Centrone, Venneri, D’Agostino, Ferrulli, Šimunič, Narici, Pisot and Valenti Neznano 2022-04-20 14:42:53 2022-04-20 14:42:54 2022-09-07 10:35:20 0000-00-00 00:00:00 2022 0 0 Nasl. z nasl. zaslona; Soavtorji: Annarita Di Mise, Marianna Ranieri, Mariangela Centrone, Maria Venneri, Mariagrazia D’Agostino, Angela Ferrulli, Boštjan Šimunič, Marco Narici, Rado Pisot, Giovanna Valenti; Opis vira z dne 20. 4. 2022; str. 1-9 art. 858867 Vol. 13 Apr. 2022 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 2022-03-07 2022-04-20 611.61:612 1664-042X 10.3389/fphys.2022.858867 105431299 ZRSKP_Tamma_Grazia_i2022.pdf ZRSKP_Tamma_Grazia_i2022.pdf 1 B91C9E8B5BABE2DB488D5A36FD2772EE 2d5ec26b94d496662155db90effbe167e2056eed78526ab9be77892f2a7d018a e81cebef-17b6-11ed-b6b8-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=19640 https://doi.org/10.3389/fphys.2022.858867 1 https://dirros.openscience.si/Dokument.php?lang=slv&id=19638 Znanstveno-raziskovalno središče Koper / Centro di Ricerche Scientifiche Capodistria 0 0 0