| 1. |
- Isaksson, Christine, et al.
(författare)
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Turnover modeling of non-esterified Fatty acids in rats after multiple intravenous infusions of nicotinic Acid.
- 2009
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Ingår i: Dose-response : a publication of International Hormesis Society. - 1559-3258. ; 7:3, s. 247-69
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this investigation was to use a pharmacokinetic (PK)/pharmacodynamic (PD) approach to describe and evaluate a PK model of nicotinic acid (NiAc) in guinea pigs and a PD feedback model of changes in non-esterified fatty acid (NEFA) concentrations in rats following multiple intravenous infusions of NiAc at different rates and durations of inhouse and literature (NEFA after extravascular NiAc dosing) data. Serial arterial blood samples were taken for evaluation of NiAc exposure in guinea pigs and NEFA in rats. The biophase kinetics of NiAc was assumed to impact on NEFA turnover with feedback incorporated via an inhibitory moderator compartment. The response acted linearly on the production of moderator, which then acted inversely on the turnover rate of response. The potency, expressed as the amount of NiAc in the biophase causing a 50 % inhibitory effect (ID(50)), was 6.5 nmol +/- 31 % and the half-life of response (t(1/2, kout)) 2 min +/- 18 %. The half-life of tolerance (t(1/2, ktol)) was 9 min +/- 27 %. The model can be used to provide information about factors that determine the time course of NEFA response following different rates and routes of administration of NiAc or NiAc analogues.
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| 2. |
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| 3. |
- Lundqvist, Johan, et al.
(författare)
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Hormetic Dose Response of NaAsO2 on Cell Proliferation of Prostate Cells in Vitro: Implications for Prostate Cancer Initiation and Therapy
- 2019
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Ingår i: Dose-Response. - : SAGE Publications. - 1559-3258. ; 17
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Tidskriftsartikel (refereegranskat)abstract
- Sodium meta-arsenite (NaAsO2) has been suggested to play a role both in initiation/progression of prostate cancer and as a future antiprostate cancer drug. We have studied the effects of NaAsO2 on cell proliferation of prostate cancer and noncancer cells, breast cancer cells, and adrenocortical carcinoma cells in vitro. Further, we have investigated the effect of NaAsO2 on the androgen receptor. We report that NaAsO2 alters the cell proliferation of prostate cells, in a hormetic manner, by increasing cell proliferation at low concentrations and decreasing the cell proliferation at high concentrations. No activation of the androgen receptor was detected. We conclude that NaAsO2 is able to increase cell proliferation of prostate cells in vitro at low concentrations, while it decreases cell viability at high concentrations. This novel finding has to be further addressed if NaAsO2 should be developed into an antiprostate cancer drug.
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| 4. |
- Rey, N., et al.
(författare)
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Exposure to Low to Moderate Doses of Ionizing Radiation Induces A Reduction of Pro-Inflammatory Ly6chigh Monocytes and a U-Curved Response of T Cells in APOE -/- Mice
- 2021
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Ingår i: Dose-Response. - : SAGE Publications. - 1559-3258. ; 19:2
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Tidskriftsartikel (refereegranskat)abstract
- Low dose ionizing radiation (LDIR) is known to have a protective effect on atherosclerosis in rodent studies, but how it impacts different cells types involved in lesion formation remains incompletely understood. We investigated the immunomodulatory response of different doses and dose-rates of irradiation in ApoE-/- mice. Mice were exposed to external γ rays at very low (1.4 mGy.h-1) or low (50 mGy.h-1) dose-rates, with cumulative doses spanning 50 to 1000 mGy. Flow cytometry of circulating cells revealed a significant decrease in pro-inflammatory Ly6CHi monocytes at all cumulative doses at low dose-rate, but more disparate effects at very low dose-rate with reductions in Ly6CHi cells at doses of 50, 100 and 750 mGy only. In contrast, Ly6CLo monocytes were not affected by LDIR. Similarly, proportions of CD4+ T cell subsets in the spleen did not differ between irradiated mice and non-irradiated controls, whether assessing CD25+FoxP3+ regulatory or CD69+ activated lymphocytes. In the aorta, gene expression of cytokines such as IL-1 and TGF-ß and adhesion molecules such as E-Selectin, ICAM-1, and VCAM-1 were reduced at the intermediate dose of 200 mGy. These results suggest that LDIR may reduce atherosclerotic plaque formation by selectively reducing blood pro-inflammatory monocytes and by impairing adhesion molecule expression and inflammatory processes in the vessel wall. In contrast, splenic T lymphocytes were not affected by LDIR. Furthermore, some responses to irradiation were nonlinear; reductions in aortic gene expression were significant at intermediate doses, but not at either highest or lowest doses. This work furthers our understanding of the impact of LDIR with different dose-rates on immune system response in the context of atherosclerosis.
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