TY - JOUR
T1 - Administration of 5-androstenediol to mice
T2 - Pharmacokinetics and cytokine gene expression
AU - Singh, V. K.
AU - Grace, M. B.
AU - Jacobsen, K. O.
AU - Chang, C. M.
AU - Parekh, V. I.
AU - Inal, C. E.
AU - Shafran, R. L.
AU - Whitnall, A. D.
AU - Kao, T. C.
AU - Jackson, W. E.
AU - Whitnall, M. H.
PY - 2008/4
Y1 - 2008/4
N2 - The development of an effective pharmacological countermeasure is needed to reduce the morbidity and mortality in military and civilian populations associated with possible exposure to ionizing radiation. Previous studies in mice have shown that a single subcutaneous (sc) injection of the natural steroid androst-5-ene-3β,17β-diol (5-androstenediol, 5-AED), 24-48 h prior to a lethal dose of whole-body 60Co gamma radiation, stimulated hematopoiesis and enhanced survival. These effects are consistent with our previous observation of 5-AED-induced elevations in circulating G-CSF in normal and irradiated mice. The purpose of this study was to obtain data on the pharmacokinetics of 5-AED after sc and buccal administration to mice, and to determine whether cytokine genes are induced by sc 5-AED in hematopoietic tissues (bone marrow, spleen). We studied effects on serum cytokines and chemokines, and also analyzed the pharmacokinetics of 5-AED after sc administration and compared it with buccal delivery. 5-AED was administered 24 h before irradiation or sham-irradiation. Cytokine mRNAs were quantified by quantitative real-time PCR (QRT-PCR), and cytokine levels in serum by multiplex Luminex. 5-AED administration was associated with elevation of message for GM-CSF, IL-2, IL-3, IL-6, and IL-10 in spleen, and GM-CSF and IL-2 in bone marrow. Irradiation enhanced G-CSF, GM-CSF, IFN-γ, TPO, IL-2, IL-3, IL-6, IL-10, and IL-12 in spleen, and GM-CSF, IFN-γ, TPO, IL-3, and IL-10 in bone marrow. Serum levels of G-CSF were significantly elevated in 5-AED-treated mice 4 h after irradiation or sham-irradiation. Serum macrophage inflammatory protein-1γ (MIP-1γ) was significantly elevated 4 h after irradiation in 5-AED-treated mice. Plasma 5-AED peaked 2 h after sc injection (30 mg/kg), and remained significantly above control after 4 days, but not 8 days. The time course of plasma 5-AED after buccal delivery (60 mg/kg) was similar, but levels were significantly lower compared to sc delivery. Plasma 5-AED 24 h after administration was not significantly different between sc and buccal delivery. However, in contrast to many studies showing enhanced survival after sc administration of 5-AED, we found no effect on survival of buccal 5-AED. The results suggest that radioprotection is not dependent on the 5-AED concentration at the time of irradiation, but rather on events triggered during the first few hours after administration. The current results suggest that further studies are warranted to directly test the roles of cytokines in the radioprotective effects of 5-AED.
AB - The development of an effective pharmacological countermeasure is needed to reduce the morbidity and mortality in military and civilian populations associated with possible exposure to ionizing radiation. Previous studies in mice have shown that a single subcutaneous (sc) injection of the natural steroid androst-5-ene-3β,17β-diol (5-androstenediol, 5-AED), 24-48 h prior to a lethal dose of whole-body 60Co gamma radiation, stimulated hematopoiesis and enhanced survival. These effects are consistent with our previous observation of 5-AED-induced elevations in circulating G-CSF in normal and irradiated mice. The purpose of this study was to obtain data on the pharmacokinetics of 5-AED after sc and buccal administration to mice, and to determine whether cytokine genes are induced by sc 5-AED in hematopoietic tissues (bone marrow, spleen). We studied effects on serum cytokines and chemokines, and also analyzed the pharmacokinetics of 5-AED after sc administration and compared it with buccal delivery. 5-AED was administered 24 h before irradiation or sham-irradiation. Cytokine mRNAs were quantified by quantitative real-time PCR (QRT-PCR), and cytokine levels in serum by multiplex Luminex. 5-AED administration was associated with elevation of message for GM-CSF, IL-2, IL-3, IL-6, and IL-10 in spleen, and GM-CSF and IL-2 in bone marrow. Irradiation enhanced G-CSF, GM-CSF, IFN-γ, TPO, IL-2, IL-3, IL-6, IL-10, and IL-12 in spleen, and GM-CSF, IFN-γ, TPO, IL-3, and IL-10 in bone marrow. Serum levels of G-CSF were significantly elevated in 5-AED-treated mice 4 h after irradiation or sham-irradiation. Serum macrophage inflammatory protein-1γ (MIP-1γ) was significantly elevated 4 h after irradiation in 5-AED-treated mice. Plasma 5-AED peaked 2 h after sc injection (30 mg/kg), and remained significantly above control after 4 days, but not 8 days. The time course of plasma 5-AED after buccal delivery (60 mg/kg) was similar, but levels were significantly lower compared to sc delivery. Plasma 5-AED 24 h after administration was not significantly different between sc and buccal delivery. However, in contrast to many studies showing enhanced survival after sc administration of 5-AED, we found no effect on survival of buccal 5-AED. The results suggest that radioprotection is not dependent on the 5-AED concentration at the time of irradiation, but rather on events triggered during the first few hours after administration. The current results suggest that further studies are warranted to directly test the roles of cytokines in the radioprotective effects of 5-AED.
KW - 5-AED
KW - Cytokines
KW - Gene expression
KW - Luminex
KW - Pharmacokinetics
UR - http://www.scopus.com/inward/record.url?scp=40949086090&partnerID=8YFLogxK
U2 - 10.1016/j.yexmp.2007.12.001
DO - 10.1016/j.yexmp.2007.12.001
M3 - Article
C2 - 18262521
AN - SCOPUS:40949086090
SN - 0014-4800
VL - 84
SP - 178
EP - 188
JO - Experimental and Molecular Pathology
JF - Experimental and Molecular Pathology
IS - 2
ER -