Single-dose kinetics of deuterium-labelled cannabidiol in man after smoking and intravenous administration

The kinetics of radioactive potassium, chloride, and water entry into endolymph, perilymph, and cerebrospinal fluid were studied after intravenous administration of tracers in anesthetized and nephrectomized rats. Samples of cochlear endolymph, perilymph of scala vestibuli, perilymph of scala tympani, and cisternal cerebrospinal fluid were obtained. The data showed: 1) a rapid turnover of water in endolymph, perilymph, and cerebrospinal fluid, since 3H2O equilibrated with plasma in a few minutes; 2) a slow entry of 42K and 36Cl in perilymph, since 36Cl equilibrated with plasma after 2 h and 42K did not at 6 h; 3) an extremely slow entry of 42K and 36Cl in endolymph, since no equilibrium with plasma was obtained within the 5 h of the experiments. The comparison of the compartmental analysis of our data with the results of other studies using perilymphatic perfusion of tracers indicated that perilymph rather than plasma may be considered as the precursor of endolymph.

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A Metabolomic Approach for the In Vivo Study of Gold Nanospheres and Nanostars after a Single-Dose Intravenous Administration to Wistar Rats

Nanomaterials ◽

10.3390/nano9111606 ◽

2019 ◽

Vol 9 (11) ◽

pp. 1606 ◽

Cited By ~ 3

Author(s):

Enea ◽

Araújo ◽

Almeida ◽

Soares ◽

Gonçalves-Monteiro ◽

...

Keyword(s):

Single Dose ◽

Intravenous Administration ◽

Wistar Rats ◽

Metabolic Effects ◽

Control Group ◽

Gold Nanospheres ◽

Gold Nanostars ◽

Different Types ◽

Metabolomic Approach

Gold nanoparticles (AuNPs) are promising nanoplatforms for drug therapy, diagnostic and imaging. However, biological comparison studies for different types of AuNPs fail in consistency due to the lack of sensitive methods to detect subtle differences in the expression of toxicity. Therefore, innovative and sensitive approaches such as metabolomics are much needed to discriminate toxicity, specially at low doses. The current work aims to compare the in vivo toxicological effects of gold nanospheres versus gold nanostars (of similar ~40 nm diameter and coated with 11-mercaptoundecanoic acid) 24 h after an intravenous administration of a single dose (1.33 × 1011 AuNPs/kg) to Wistar rats. The biodistribution of both types of AuNPs was determined by graphite furnace atomic absorption spectroscopy. The metabolic effects of the AuNPs on their main target organ, the liver, were analyzed using a GC-MS-based metabolomic approach. Conventional toxicological endpoints, including the levels of ATP and reduced and oxidized glutathione, were also investigated. The results show that AuNPs preferentially accumulate in the liver and, to a lesser extent, in the spleen and lungs. In other organs (kidney, heart, brain), Au content was below the limit of quantification. Reduced glutathione levels increased for both nanospheres and nanostars in the liver, but ATP levels were unaltered. Multivariate analysis showed a good discrimination between the two types of AuNPs (sphere- versus star-shaped nanoparticles) and compared to control group. The metabolic pathways involved in the discrimination were associated with the metabolism of fatty acids, pyrimidine and purine, arachidonic acid, biotin, glycine and synthesis of amino acids. In conclusion, the biodistribution, toxicological, and metabolic profiles of gold nanospheres and gold nanostars were described. Metabolomics proved to be a very useful tool for the comparative study of different types of AuNPs and raised awareness about the pathways associated to their distinct biological effects.

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Pharmaco-kinetics of Cisapride in Dairy Cattle after Intravenous Administration

Journal of the Japan Veterinary Medical Association ◽

10.12935/jvma1951.55.77 ◽

2002 ◽

Vol 55 (2) ◽

pp. 77-79 ◽

Cited By ~ 1

Author(s):

Naoyuki TAKEMURA ◽

Hiroyuki MASUDA ◽

Hisashi HIROSE ◽

Masahiro TAGAWA

Keyword(s):

Dairy Cattle ◽

Intravenous Administration ◽

Kinetics Of

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The Pharmacokinetics of a Single Dose of Calcitriol Administered Subcutaneously in Continuous Ambulatory Peritoneal Dialysis Patients

Peritoneal Dialysis International ◽

10.1177/089686089301300208 ◽

1993 ◽

Vol 13 (2) ◽

pp. 122-125 ◽

Cited By ~ 8

Author(s):

Rafael Selgas ◽

Maria-E. Martinez ◽

Blanca Miranda ◽

Maria-Auxiliadara Baja ◽

Jase-Raman Ramera ◽

...

Keyword(s):

Single Dose ◽

Peritoneal Dialysis ◽

Continuous Ambulatory Peritoneal Dialysis ◽

Plasma Levels ◽

Subcutaneous Administration ◽

Area Under The Curve ◽

Serum Levels ◽

Mean Value ◽

Ionized Calcium ◽

Kinetics Of

Objectives To evaluate the kinetics of calcitriol (1,25(OH)2D3) administered subcutaneously. Study Design Calcitriol kinetics and efficacy after subcutaneous administration were studied in 13 CAPD patients with varying degrees of increased plasma levels of parathyroid hormone (i-PTH). A single dose of 2 μg of calcitriol was administered subcutaneously, and its serum levels at baseline and after 1,2,6,12, and 24 hours were determined. Plasma ionized calcium and i-PTH were also determined at these periods. Results Serum calcitriol levels reached peak levels of 60 and 70 pg/mL at 1 and 2 hours after administration, respectively. These levels decreased thereafter, but remained above baseline values during 24 hours. The mean value of the area under the curve (AUC) was 809±226 pg/mL/hour. Plasma i-PTH levels showed a slight decrease after 1 and 2 hours, returning to baselime levels after this period. Plasma ionized calcium did not show significant changes during the study. A slight pain at the site of injection was mentioned by some patients. Conclusions The subcutaneous route for calcitriol administration achieves theoretically adequate plasma levels in continuous ambulatory peritoneal dialysis (CAPD) patients. This is important when paremteral administration of calcitriol is considered in the treatment of secondary hyperparathyroidism.

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