The Distribution of [14C]Cholesterol in Muscle and Skin of Rhesus Monkeys after Intravenous Injection

1976 ◽  
Vol 50 (4) ◽  
pp. 307-310
Author(s):  
C. D. Moutafis ◽  
N. B. Myant
Keyword(s):  
Intravenous Injection ◽  
Rhesus Monkeys ◽  
Plasma Cholesterol ◽  
Specific Radioactivity ◽  
Compartment System ◽  
Local Synthesis ◽  
Single Intravenous Injection ◽  
Small Pool ◽  
Slow Turnover

1. The specific radioactivity of [14C]cholesterol in plasma and in serial biopsies of muscle and skin was measured in Rhesus monkeys for 156 days after a single intravenous injection of [14C]cholesterol. 2. Analysis of the specific radioactivity—time curves in terms of a two-compartment system indicated that all the cholesterol of muscle is exchangeable with the plasma cholesterol and that local synthesis does not contribute significantly to the cholesterol in muscle. 3. Analysis of the curve for specific radioactivity of skin cholesterol suggested the presence of a small pool of cholesterol with slow turnover. A contribution to skin cholesterol from local synthesis could not be excluded.

The Lipids and Lipoproteins of Human Peripheral Lymph, with Observations on the Transport of Cholesterol from Plasma and Tissues into Lymph

1973 ◽  
Vol 45 (3) ◽  
pp. 313-329 ◽  
Author(s):  
D. Reichl ◽  
L. A. Simons ◽  
N. B. Myant ◽  
J. J. Pflug ◽  
G. L. Mills
Keyword(s):  
Total Cholesterol ◽  
Intravenous Injection ◽  
Plasma Cholesterol ◽  
Human Subjects ◽  
Specific Radioactivity ◽  
Cholesterol Concentration ◽  
Apo B ◽  
Peripheral Lymph ◽  
Lipids And Lipoproteins ◽  
Slow Turnover

1. The lipids and lipoproteins of lymph obtained from the dorsum of the foot were examined in seven human subjects. 2. The concentration of total cholesterol in lymph was about one-tenth that in plasma and was significantly correlated with the plasma total cholesterol concentration. The ratio of esterified to total cholesterol in lymph was similar to that in plasma. 3. Triglyceride was detectable in lymph, but the concentration was less than one-tenth that in plasma and was unrelated to the plasma triglyceride concentration. 4. No lipase activity was detectable in lymph, either before or after intravenous injection of heparin. 5. Cholesterol-esterifying activity was detected in four samples of lymph. 6. The major lipoprotein antigens of human plasma (apo-A, apo-B and apo-C) were present in whole lymph, but their distribution in fractions of different density was different from that in plasma. 7. [14C]Cholesterol, injected intravenously, appeared in lymph within 30 min of the injection, indicating that some of the cholesterol in lymph is derived directly from plasma. 8. At intervals greater than 29 days after a single intravenous injection of [14C]-cholesterol, the specific radioactivity of lymph cholesterol was greater than that of plasma cholesterol, indicating that some of the cholesterol in lymph is derived from tissue pools of cholesterol with slow turnover.

Cholesterol turnover in miniature swine with a portacaval shunt

1979 ◽  
Vol 57 (12) ◽  
pp. 1381-1387 ◽  
Author(s):  
Yung-Sheng Huang ◽  
Suzanne Lussier-Cacan ◽  
Maurice Bidallier ◽  
Liang-Huei Tsay ◽  
Marcel J. Rheault ◽  
...  
Keyword(s):  
Intravenous Injection ◽  
Digital Computer ◽  
Plasma Cholesterol ◽  
Specific Radioactivity ◽  
Portacaval Shunt ◽  
Hypocholesterolemic Effect ◽  
Miniature Swine ◽  
Pool Model

Plasma cholesterol turnover was studied in sham-operated and portacaval-shunted miniature swine following an intravenous injection of labeled cholesterol. The specific radioactivity – time curves for periods of 6–7 weeks and 11–13 weeks were analyzed in both groups by a digital computer according to a two-pool and a three-pool model. In this study, the three-pool model generally provided a better fit to the observed data than did the two-pool model. The half-lives of the first and second exponents were significantly decreased in the shunted animals, indicating an elevated turnover of cholesterol. It is suggested that increased hepatic degradation of cholesterol was responsible for the hypocholesterolemic effect of the shunt in our study.

scholarly journals Rapid mobilization of hematopoietic progenitor cells in rhesus monkeys by a single intravenous injection of interleukin-8

Blood ◽  
1996 ◽  
Vol 87 (2) ◽  
pp. 781-788 ◽  
Author(s):  
L Laterveer ◽  
IJ Lindley ◽  
DP Heemskerk ◽  
JA Camps ◽  
EK Pauwels ◽  
...  
Keyword(s):  
Stem Cells ◽  
Progenitor Cells ◽  
Intravenous Injection ◽  
Rhesus Monkeys ◽  
Interleukin 8 ◽  
Hematopoietic Progenitor Cells ◽  
Hematopoietic Progenitor ◽  
Hematopoietic Stem ◽  
Single Intravenous Injection ◽  
Cell Counts

Interleukin-8 (IL-8) is a chemoattractant cytokine involved in chemotaxis and activation of neutrophils. Because in vivo administration of IL-8 induces mobilization of hematopoietic stem cells in mice, we assessed the mobilizing properties of IL-8 in rhesus monkeys. Recombinant human IL-8 was administered as a single intravenous injection at doses of 10, 30, and 100 micrograms/kg to rhesus monkeys (age, 2 to 3 years; weight, 2.5 to 4.5 kg). Venous blood samples were obtained at time intervals ranging from 1 to 480 minutes after IL-8 administration. Cell counts, colony-forming unit-Mix assays, and fluorescence-activated cell sorter analysis were performed. Plasma was harvested to assess IL-8 levels. A time-controlled bolus intravenous injection of 100 micrograms IL-8 per kilogram of body weight resulted in peak IL-8 plasma levels up to 5 micrograms/mL. The calculated half-time life of free IL-8 was 9.9 +/- 2.2 minutes. IL-8 injection resulted in instant neutropenia that was due to pulmonary sequestration, as shown using 99mTc-labeled leukocytes. Within 30 minutes after IL-8 injection, neutrophilia developed with counts up to 10-fold greater than baseline levels. The numbers of hematopoietic progenitor cells (HPCs) increased from 45 +/- 48/mL to 1,382 +/- 599/mL of blood at 30 minutes after injection of 100 micrograms IL-8 per kilogram of bodyweight (mean +/- SD, n = 8). Individual animals showed 10- to 100-fold increase in numbers of circulating HPCs that returned to almost pretreatment values (92 +/- 52 CFU/mL) at 240 minutes after the injection of IL-8. Immunophenotyping showed no significant changes in lymphocyte (sub)populations. A second bolus injection of IL-8 with an interval of 72 hours resulted in similar numbers of mobilized stem cells as observed after the first injection, showing that no tachyphylaxis had occurred. We conclude that IL-8 induces mobilization of HPCs from the bone marrow of rhesus monkeys in a rapid and reproducible fashion. Therefore, IL-8 may be a potentially useful cytokine in the setting of blood stem cell transplantation.

RATE OF DISAPPEARANCE OF GROWTH HORMONE FROM THE PLASMA OF RATS AFTER A SINGLE INTRAVENOUS INJECTION

1955 ◽  
Vol 19 (2) ◽  
pp. 181-184 ◽  
Author(s):  
Carl A. Gemzell ◽  
Frank Heijkenskjöld ◽  
Lars Ström
Keyword(s):  
Growth Hormone ◽  
Intravenous Injection ◽  
Single Intravenous Injection

Pharmacokinetics and Tissue Residues of Sulfathiazole and Sulfamethazine in Pigs

1994 ◽  
Vol 57 (9) ◽  
pp. 796-801 ◽  
Author(s):  
LIEVE S. G. VAN POUCKE ◽  
CARLOS H. VAN PETEGHEM
Keyword(s):  
Intravenous Injection ◽  
Half Life ◽  
Intramuscular Injection ◽  
Compartment Model ◽  
Absolute Bioavailability ◽  
Pharmacokinetic Parameters ◽  
Tissue Concentrations ◽  
Single Intravenous Injection ◽  
The Individual ◽  
Residue Study

The plasma pharmacokinetics and tissue penetration of sulfathiazole (ST) and sulfamethazine (SM) after intravenous and intramuscular injection in pigs were studied. Following a single intravenous dose of 40 mg ST/kg of bodyweight or 80 mg SM/kg of bodyweight, the plasma ST and SM concentrations were best fitted to a two-compartment model. The areas under the curve were 447 ± 39 and 1485 ± 41 mg/h/L, clearances were 0.090 ± 0.007 and 0.054 ± 0.001 L/kg/h, volumes of distribution were 1.16 ± 0.16 and 0.77 ± 0.06 L/kg, half-lifes in distribution phase were l.18 ± 0.57 and 0.23 ± 0.16 h and half-lifes in eliminations phase were 9.0 ± l.6 and 9.8 ± 0.6 h. When the two compounds were administered simultaneously as a single intravenous injection, the pharmacokinetic parameters for ST were not significantly different. The values for SM show statistical differences for some important parameters: α, β and the AUC0–>∞ were significantly decreased and t1/2α, Vd and CIB were significantly increased. It can be concluded that after a single intravenous injection of 40 mg/kg, sulfathiazole has a high tl/2β resulting in higher tissue concentrations. This half-life, which is higher than what is reported in the literature, is not influenced by the simultaneous presence of sulfamethazine. The tl/2β for sulfamethazine after a single intravenous injection of 80 mg/kg is comparable to the data from the literature and is not influenced by the presence of sulfathiazole. Sulfathiazole and SM were also administered simultaneously as an intramuscular injection to healthy pigs at a dosage of 40 and 80 mg/kg bodyweight. Pharmacokinetic experiments were conducted on three pigs. From this pharmacokinetic study it can be concluded that upon a single intramuscular administration of 40 mg/kg of ST and 80 mg/kg of SM the absolute bioavailability in pigs is 0.92 ± 0.04 for ST and l.01 ± 0.07 for SM. Six pigs received five intramuscular im) injections as a single dose of ST and SM every 24 h for five consecutive days for the residue study. The pigs were slaughtered at different times after the last dose was given and samples were taken from various tissues and organs. Concentrations were determined by a microbiological method and a HPTLC method. No edible tissue contained more than 100 μg/kg of the individual sulfonamides after 10 days of withdrawal. It means that adult animals which have a shorter half-life and thus lower tissue concentrations will certainly meet the economic community EC) maximum residue limits after a 10 days withdrawal period.

scholarly journals Compartmentation between glycolysis and gluconeogenesis in rat liver

1968 ◽  
Vol 110 (2) ◽  
pp. 303-312 ◽  
Author(s):  
C. J. Threlfall ◽  
D. F. Heath
Keyword(s):  
Kinetic Analysis ◽  
Intravenous Injection ◽  
Rat Liver ◽  
Isotopic Exchange ◽  
Direct Evidence ◽  
Specific Radioactivity ◽  
Glycolytic Pathway ◽  
Glucose Phosphorylation

1. The specific radioactivity–time relationships of glucose, glucose 6-phosphate, glycerol 1-phosphate and UDP-glucose were determined in rat liver after the intravenous injection of [U−14C]fructose, and a kinetic analysis was carried out. The glucose 6-phosphate pool was found to be compartmented into gluconeogenic and glycolytic components, and evidence was obtained that the triose phosphates were similarly compartmented. The glycolytic pathway was fed by glycogenolysis and glucose phosphorylation. There was no direct evidence that glycogenolysis fed only the glycolytic pathway, but this interpretation would make the liver resemble other organs in this respect. 2. UDP-glucose was not formed solely from gluconeogenic glucose 6-phosphate, as there was some dilution of label in the intervening glucose 1-phosphate pool, probably from glycogenolysis, though other pathways cannot be excluded. 3. The data cannot be explained by isotopic exchange.

Hypercholesterolemia of total starvation: its mechanism via tissue mobilization of cholesterol

1975 ◽  
Vol 229 (2) ◽  
pp. 365-369 ◽  
Author(s):  
JC Swaner ◽  
WE Connor
Keyword(s):  
Adipose Tissue ◽  
Cholesterol Metabolism ◽  
Plasma Cholesterol ◽  
Specific Radioactivity ◽  
Cholesterol Content ◽  
Cholesterol Concentration ◽  
Tissue Cell ◽  
Adipose Tissue Cell ◽  
Total Starvation ◽  
Linear Decay

After the establishment of a relatively linear decay curve for plasma [4-14C]cholesterol, rabbits were starved for 26-32 days. The plasma cholesterol concentration increased 400% during starvation. Concurrently, the plasma triglyceride level declined by 50%. While the plasma cholesterol was rising, the cholesterol specific radioactivity of the plasma remained unchanged in starved animals, but in control animals the plasma cholesterol specific radioactivity declined substantially. The cholesterol content of the liver and adipose tissue increased with starvation. The cholesterol specific radioactivities relative to plasma for adipose tissue were lower in the starved animals versus controls. These results support the hypothesis that cholesterol stored in the lipid droplet of the adipose tissue cell is released into plasma and is the chief source of the hypercholesterolemia observed during complete caloric starvation. Cholesterol metabolism in the starved animal can be depicted as a virtually closed system in both the input from biosynthesis and diet being low or zero and the output likewise being close to zero.

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