scholarly journals Different Influences on Tacrolimus Pharmacokinetics by Coadministrations of Zhi Ke and Zhi Shi in Rats

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Shiuan-Pey Lin ◽  
Ping-Ping Wu ◽  
Yu-Chi Hou ◽  
Shang-Yuan Tsai ◽  
Meng-Ju Wang ◽  
...  
Keyword(s):  
Cell Line ◽  
Therapeutic Window ◽  
Blood Levels ◽  
Sprague Dawley ◽  
Glycoprotein P ◽  
Transplant Patients ◽  
Sprague Dawley Rats ◽  
Microparticle Enzyme Immunoassay ◽  
Mechanism Of Interaction ◽  
Tacrolimus Pharmacokinetics

Tacrolimus, an immunosuppressant with narrow therapeutic window, has been used widely in transplant patients. Grapefruit juice and pomelo have been reported to increase the blood levels of tacrolimus. Zhi Ke and Zhi Shi, the ripe peels and unripe fruits ofCitrus aurantiumwhich is chemotaxonomically related to grapefruit and pomelo, are in wide use in clinical Chinese medicine. To investigate the possible interaction of these twoCitrusherbs with tacrolimus, male Sprague-Dawley rats were orally given tacrolimus (1.5 mg/kg) with and without Zhi Ke and Zhi Shi decoctions in a cross-over design. Blood samples were withdrawn via cardiopuncture at specific time and quantitated by a microparticle enzyme immunoassay. In addition, to explore the mechanism of interaction, LS 180 cell line was used for the transport study of rhodamine 123, a typical substrate of P-glycoprotein (P-gp). The results showed that Zhi Shi significantly decreased theCmax⁡andAUC0-tof tacrolimus by 72.4% and 72.0%, respectively, whereas Zhi Ke did not affect tacrolimus pharmacokinetics. LS 180 cell line study indicated that Zhi Shi increased the efflux activity of P-gp, enabling us to explain the decreased oral bioavailability of tacrolimus caused by Zhi Shi. Hence, we suggest that Zhi Shi be contraindicated for transplant patients treated with tacrolimus to reduce the risk of allograft rejection.

scholarly journals Evaluation of the Influence of Zhenwu Tang on the Pharmacokinetics of Digoxin in Rats Using HPLC-MS/MS

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Chao Li ◽  
Dahu Liang ◽  
Yanhao Liu ◽  
Chaozhuang Shen ◽  
Xiaohu Wang ◽  
...  
Keyword(s):  
Deionized Water ◽  
Therapeutic Window ◽  
Sprague Dawley ◽  
Glycoprotein P ◽  
Active Efflux ◽  
Time Points ◽  
Sprague Dawley Rats ◽  
Combined Use ◽  
Positive Inotropic Drug ◽  
Excised Tissues

Digoxin (DIG) is a positive inotropic drug with a narrow therapeutic window that is used in the clinic for heart failure. The active efflux transporter of DIG, P-glycoprotein (P-gp), mediates DIG absorption and excretion in rats and humans. Up to date, several studies have shown that the ginger and Poria extracts in Zhenwu Tang (ZWT) affect P-gp transport activity. This study aimed to explore the effects of ZWT on the tissue distribution and pharmacokinetics of DIG in rats. The deionized water or ZWT (18.75 g/kg) was orally administered to male Sprague–Dawley rats once a day for 14 days as a pretreatment. On day 15, 1 hour after receiving deionized water or ZWT, the rats were given the solution of DIG at 0.045 mg/kg dose, and the collection of blood samples was carried out from the fundus vein or excised tissues at various time points. HPLC-MS/MS was used for the determination of the DIG concentrations in the plasma and the tissues under investigation. The pharmacokinetic interactions between DIG and ZWT after oral coadministration in rats revealed significant reductions in DIG Cmax and AUC0-∞, as well as significant increases in T1/2 and MRT0-∞. When coadministered with ZWT, the DIG concentration in four of the investigated tissues statistically decreased at different time points except for the stomach. This study found that combining DIG with ZWT reduced not only DIG plasma exposure but also DIG accumulation in tissues (heart, liver, lungs, and kidneys). The findings of our study could help to improve the drug's validity and safety in clinical applications and provide a pharmacological basis for the combined use of DIG and ZWT.

Pulmonary vascular pressure effects by endothelin-1 in normoxia and chronic hypoxia: a longitudinal study

1996 ◽  
Vol 271 (6) ◽  
pp. H2246-H2253 ◽  
Author(s):  
S. Tjen-A-Looi ◽  
R. Ekman ◽  
J. Osborn ◽  
I. Keith
Keyword(s):  
Pulmonary Hypertension ◽  
Ventricular Hypertrophy ◽  
Pressure Effects ◽  
Blood Levels ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Calcitonin Gene ◽  
Eta Receptor ◽  
Pulmonary Arterial

The role of endothelin (ET)-1 in pulmonary arterial pressure (Ppa) homeostasis and hypoxia-induced pulmonary hypertension was examined. ET-1 was chronically infused (2 and 4 pmol.kg-1.min-1) into the pulmonary circulation of male Sprague-Dawley rats for 3, 7, and 14 days while they were exposed to normoxia or hypobaric hypoxia (inspired O2 fraction 10%). The role of endogenous ET was examined by infusion of ET antiserum (ET-AS; 0.25 and 0.5 microliter.rat-1.h-1; cross-reacting with ET-1, -2, and -3) or the ETA-receptor blocker BQ-123 (10 pmol.kg-1.min-1). ET-1 (4 pmol) increased Ppa at 3 and 7 days in normoxia and hypoxia and was ineffective at 14 days, probably from ETA-receptor downregulation. BQ-123 blunted the hypoxic Ppa rise at all times, confirming a role for ETA receptors. ET-AS (0.5 microliter) was mostly ineffective but exacerbated hypoxic Ppa at 14 days, in contrast to BQ-123, suggesting that a different ET receptor could be involved. ET-1 infusion (2 pmol) caused right ventricular hypertrophy (RVH) in normoxia and exacerbated RVH in hypoxia, whereas BQ-123 and ET-AS (0.25 microliter) reduced hypoxic RVH. In conclusion, endogenous ET-1 plays a role in hypoxia-induced pulmonary hypertension and RVH by augmenting the level of hypoxic response. ET-1 also affects hematocrit and may reduce blood levels of the vasodilator calcitonin gene-related peptide.

Effect of circulating vasopressin on arterial pressure regulation in rats

1989 ◽  
Vol 257 (1) ◽  
pp. H209-H218 ◽  
Author(s):  
C. M. Pawloski ◽  
N. M. Eicker ◽  
L. M. Ball ◽  
M. L. Mangiapane ◽  
G. D. Fink
Keyword(s):  
Heart Rate ◽  
Arterial Pressure ◽  
Body Fluid ◽  
Area Postrema ◽  
Sodium Intake ◽  
Blood Levels ◽  
Fluid Composition ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Autonomic Cardiovascular Control

It has been hypothesized that moderately increased blood levels of arginine vasopressin (AVP) contribute to the development and/or maintenance of hypertension. In this study, male Sprague-Dawley rats on a fixed 1 meq daily sodium intake received 10-day intravenous infusions of 0.2 and 2.0 ng.kg-1.min-1 AVP. The higher infusion rate was above the acute vasoconstrictor threshold for AVP administration and also produced a maximal antidiuretic effect. During chronic AVP administration, however, daily mean arterial pressure, heart rate, and body fluid composition were not changed, despite a maintained antidiuresis. To test the hypothesis that circulating AVP failed to cause hypertension as a result of sensitization of the baroreflex or a direct sympathoinhibitory effect of the peptide, additional experiments were performed in rats subjected to sinoaortic denervation (SAD) or ablation of the area postrema (APX). Infusion of AVP for 10 days into SAD or APX rats caused a sustained antidiuresis but did not change arterial pressure, heart rate, or body fluid composition. In all groups of rats, the depressor response to ganglionic blockade (20 mg/kg hexamethonium) was used to estimate the autonomic component of resting arterial pressure; no change in autonomic cardiovascular control was found using this method in any of the groups during AVP infusion. Long-term elevation of plasma AVP in rats, therefore, does not cause hypertension or significantly affect autonomic regulation of arterial pressure.

Influence of spaceflight on the production of interleukin-3 and interleukin-6 by rat spleen and thymus cells

1995 ◽  
Vol 78 (3) ◽  
pp. 810-813 ◽  
Author(s):  
E. S. Miller ◽  
D. A. Koebel ◽  
G. Sonnenfeld
Keyword(s):  
Cell Line ◽  
Space Shuttle ◽  
Biologically Active ◽  
Sprague Dawley ◽  
Spleen Cells ◽  
Interleukin 3 ◽  
Sprague Dawley Rats ◽  
Dependent Cell ◽  
Thymus Cells ◽  
Stimulating Factor

Six adult male Sprague-Dawley rats were flown on the 7-day US space shuttle mission STS-54. After flight, the spleen and thymus from each animal were assayed for the capacity to secrete the cytokines interleukin-3 (IL-3) and IL-6. Spleen and thymus cells (5 x 10(6)/ml) were incubated for 48 h in the presence of 5 micrograms/ml of concanavalin A or 2 micrograms/ml of bacterial lipopolysaccharide to stimulate the production of IL-3 and IL-6. IL-3 activity was measured using the IL-3/colony-stimulating-factor-dependent cell line 32D. IL-6 activity was measured using the IL-6-dependent cell line 7TD1. Spleen and thymus cells harvested from flown rats secreted significantly higher titers of biologically active IL-3 compared with ground control rats. Spaceflight significantly enhanced IL-6 production by thymus, but not spleen, cells. The results of this study demonstrate that spaceflight can enhance the production of certain cytokines by cells of the immune system.

scholarly journals Pharmacokinetics and Central Accumulation of Delta-9-Tetrahydrocannabinol (THC) and its Bioactive Metabolites are Influenced by Route of Administration and Sex

2021 ◽  
Author(s):  
Samantha L Baglot ◽  
Catherine Hume ◽  
Gavin N. Petrie ◽  
Robert J Aukema ◽  
Savannah HM Lightfoot ◽  
...  
Keyword(s):  
Animal Studies ◽  
Data Interpretation ◽  
Bioactive Metabolites ◽  
Blood Levels ◽  
Administration Route ◽  
Sprague Dawley ◽  
North Americans ◽  
Sprague Dawley Rats ◽  
Cannabis Consumption ◽  
Over Time

Up to a third of North Americans over 16 years old report using cannabis in the prior month, most commonly through inhalation. Animal models that reflect human cannabis consumption are critical to study its impacts on brain and behaviour. Nevertheless, most animal studies to date examine effects of cannabis through injection of delta-9-tetrahydrocannabinol (THC; primary psychoactive component of cannabis). THC injections produce markedly different physiological and behavioural effects than inhalation, likely due to distinctive pharmacokinetics of each administration route. The current study directly examined if administration route (injection versus inhalation), with dosing being matched on peak THC blood levels, alters the metabolism of THC, and the central accumulation of THC and its metabolites over time. Adult male and female Sprague-Dawley rats received either a single intraperitoneal injection of THC (2.5 mg/kg) or a single (15 min) session of inhaled exposure to THC distillate (100 mg/mL) vapour. Blood and brains were collected at 15, 30, 60, 90 and 240 minutes post-exposure for analysis of THC and metabolites through mass spectrometry-liquid chromatography. Inhalation results in immediate hypothermia, whereas injection results in delayed hypothermia. Despite achieving comparable peak concentrations of blood THC in both groups, our results indicate higher initial brain THC concentration following inhalation, whereas injection resulted in dramatically higher 11-OH-THC concentrations, a potent THC metabolite, in blood and brain that increased over time. Our results provide evidence that THC and its metabolites exhibit different pharmacokinetic profiles following inhalation versus injection, which could have significant impacts for data interpretation and generalizability. Accordingly, we suggest that translational work in the realm of THC and cannabis strongly consider using inhalation models over those that employ injection.

scholarly journals EXTH-71. IND-ENABLING CHARACTERIZATION OF ONC206 AS THE NEXT BITOPIC DRD2 ANTAGONIST FOR NEURO-ONCOLOGY

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi97-vi97 ◽  
Author(s):  
Varun Prabhu ◽  
Abed Rahman Kawakibi ◽  
Neel Madhukar ◽  
Mathew Garnett ◽  
Ultan McDermott ◽  
...  
Keyword(s):  
Body Weight ◽  
Cell Lines ◽  
Body Weight Gain ◽  
Human Fibroblasts ◽  
Xenograft Model ◽  
Therapeutic Window ◽  
Sprague Dawley ◽  
Toxic Dose ◽  
Biodistribution Studies ◽  
Sprague Dawley Rats

Abstract ONC201 is the first clinical bitopic antagonist of DRD2, an oncogenic receptor in brain and neuroendocrine tumors. ONC206, a derivative of ONC201 that shares the imipridone core structure, is also a bitopic DRD2 antagonist that exhibits enhanced non-competitive effects, high specificity, nanomolar potency, and disruption of DRD2 homodimers. Broad nanomolar efficacy of ONC206 (GI50 < 78-889nM, CellTitre-Glo, 72h) was observed in >1,000 GDSC cancer cell lines. Maximal ONC206 sensitivity was observed in pheochromocytoma, high-grade gliomas, neuroblastoma, medulloblastoma, sarcoma and cholangiocarcinoma cell lines exhibiting a DRD2+/DRD5- RNA expression signature. An exposure time of 48h at nanomolar concentrations was sufficient for maximal inhibition of tumor cell viability. ONC206 reduced the viability of normal human fibroblasts at higher doses (GI50 > 5µM), suggesting a wide therapeutic window. Antitumor efficacy without body weight loss was observed with 50 mg/kg weekly oral ONC206 in a dopamine-secreting HuCCT1 cholangiocarcinoma subcutaneous xenograft model. Biodistribution studies in Sprague-Dawley rats revealed a ~12 µM plasma Cmax with a systemic terminal half-life of ~6 hours upon a single oral dose of 50 mg/kg. Additionally, 5–10 fold higher ONC206 concentrations were observed in adrenal gland, bile duct, brain and bone marrow relative to plasma. Nanomolar concentrations were also observed in the CSF above DRD2 antagonism thresholds, unlike ONC201. GLP toxicology studies with weekly oral ONC206 in Sprague-Dawley rats and beagle dogs revealed no dose-limiting toxicities. Mild and reversible decreased body weight and/or body weight gain with no effects on food consumption were observed at the highest evaluated dose in both species. The highest non-severely toxic dose (HNSTD) was ≥ 16.7 mg/kg in dogs and ≥ 50 mg/kg in rats that exceeds efficacious doses in preclinical models. Using standard allometric scaling, a 90 mg starting dose of ONC206 was selected for the first-in-human clinical trial in biomarker-defined adult recurrent CNS tumors.

Diabetes in pregnancy: influence of genetic background and maternal diabetic state on the incidence of skeletal malformations in the fetal rat

1986 ◽  
Vol 113 (3_Suppl) ◽  
pp. S66-S73 ◽  
Author(s):  
Ulf J. Eriksson ◽  
V. Elisabeth Dahlström ◽  
Hans O. Lithell
Keyword(s):  
Female Rats ◽  
Blood Levels ◽  
Suitable Model ◽  
Sprague Dawley ◽  
Pregnant Rats ◽  
Diabetic State ◽  
Skeletal Malformations ◽  
Sprague Dawley Rats ◽  
Fetal Rat ◽  
Rat Strain

Abstract. Female Sprague-Dawley rats from two different substrains (denoted U and H rats) were made manifest diabetic (MD) with a single iv injection of streptozotocin 2–4 weeks before mating. In some MD animals insulin treatment was started 1–3 weeks before mating (denoted MDI rats) and in a majority of these animals the treatment was interrupted during two days of pregnancy, i.e. gestational days 2 + 3, 4 + 5, 6 + 7, 8 + 9 or 10 + 11. The pregnant rats were killed on gestational day 20. The offspring of MD and MDI rats of the U substrain showed skeletal malformations (micrognathia and sacral dysgenesis) at a rate up to 19%, whereas the MD and MDI fetuses of the H strain did not display any skeletal malformations. Offspring of the U strain with sacral dysgenesis exhibited lack of a tail and no staining of osseous and cartilagenous tissue in the sacral-caudal region, suggesting total absence of vertebrae. The offspring of the dibetic U rats tended to be more readily resorbed, were smaller and tended to have slightly larger placentae than those of the diabetic H rats. The severity of the diabetic state in pregnant and nonpregnant female rats – as reflected by body and kidney weights, blood levels of HbA1c, carbohydrate and lipid metabolites – did not differ significantly between the U and H rats. These results are in concert with the notion that congenital malformations result from a teratogenic insult in a genetically predisposed organism. The described malformation-prone rat strain (U) may be a suitable model for the future elucidation of teratological mechanisms in diabetic pregnancy.

Oral Bioavailability of Cyclotrimethylenetrinitramine (RDX) from Contaminated Site Soils in Rats

2008 ◽  
Vol 27 (4) ◽  
pp. 317-322 ◽  
Author(s):  
Lee C. B. Crouse ◽  
Mark W. Michie ◽  
Michael A. Major ◽  
Glenn J. Leach ◽  
Gunda Reddy
Keyword(s):  
Contaminated Soil ◽  
Contaminated Soils ◽  
Oral Bioavailability ◽  
Risk Assessments ◽  
Contaminated Site ◽  
Blood Levels ◽  
Sprague Dawley ◽  
Peak Absorption ◽  
Sprague Dawley Rats ◽  
Soil And Water

Cyclotrimethylenetrinitramine (RDX), a commonly used military explosive, was detected as a contaminant of soil and water at Army facilities and ranges. This study was conducted to determine the relative oral bioavailability of RDX in contaminated soil and to develop a method to derive bioavailability adjustments for risk assessments using rodents. Adult male Sprague-Dawley rats preimplanted with femoral artery catheters were dosed orally with gelatin capsules containing either pure RDX or an equivalent amount of RDX in contaminated soils from Louisiana Army Ammunition Plant (LAAP) (2300 μg/g of soil) or Fort Meade (FM) (670 μg/g of soil). After dosing rats, blood samples were collected from catheters at 2-h intervals (2, 4, 6, 8, 10, and 12) and at 24 and 48 h. RDX levels in the blood were determined by gas chromatography. The results show that the peak absorption of RDX in blood was 6 h for neat RDX (1.24 mg/kg) and for RDX from contaminated soil (1.24 mg/kg) of LAAP. Rats dosed with RDX-contaminated FM soil (0.2 mg/kg) showed peak levels of RDX in blood at 6 h, whereas their counterparts that received an identical dose (0.2 mg/kg) of neat RDX showed peak absorption at 4 h. The blood levels of absorbed RDX from LAAP soil were about 25% less than for neat RDX, whereas the bioavailability of RDX from FM soils was about 15% less than that seen in rats treated with neat RDX (0.2 mg/kg). The oral bioavailability in rats fed RDX in LAAP soil and the FM soil was reduced with the neat compound but decrease in bioavailability varied with the soil type.

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