Ear vein

Unless otherwise specified in the individual protocol, inject 10 ml of the test solution per kilogram of body weight into an ear vein of each of three rabbits, completing each injection within 10 min after the start of administration. The test solution is either the product, constituted if necessary as directed in the labeling, or the material under test. For pyrogen testing of devices or injection assemblies, use... 

Rabbit Immunization. Six rabbits were sub-cutaneously injected with. 2 mg of the immunogen in Freund s adjuvent on days 0, 12, 26, 40 and 59 of the immunization schedule (see Table I). Complete adjuvent was used for the first three immunizations followed by incomplete adjuvent for the final two immunizations. The rabbits were bled as needed using ear vein puncture. 

Two weeks after the second injection, test bleed the rabbit from an ear vein. Swab the ear with xylene to dilate the vein before bleeding. 

The mixture is injected once a week for 3 weeks, and then the animal is maintained for 3 weeks without additional injections. Approximately 25-40 ml of blood is removed from the animal s ear vein to test for antibodies. One week after the first bleed the rabbit is boosted with half the antigen amount used earlier along with incomplete adjuvant incomplete adjuvant does not contain the mycobacteria. Serum is again removed 2 weeks after this injection and tested for antibody response. The enzyme-linked immunosorbent assay is used to determine if the titer (or antibody concentration) of the serum is sufficiently high to establish antibody binding to the antigen. This 3-week cycle is repeated as long as necessary to obtain the antibodies desired. 

Bleed from marginal ear vein on d 60 and then every 28 d until antibody titre drops. 

Inject 0.5 mL of the inIn-eosinophil suspension (5 x 106 cells/guinea pig) via the marginal ear vein (the hind foot dorsal vein can also be used). We use 27-gauge needles. 

A 24-gauge catheter (Angiocath, Becton-Dickinson, Sandy, UT) is placed in the marginal ear vein for induction and maintenance of anesthesia. 

Oral blood glucose lowering substances are applied by gavage in 1 ml/kg of 0.4% starch suspension or intravenously in solution. Several doses are given to different groups. One control group receives the vehicle only. By puncture of the ear veins, blood is withdrawn immediately before and 1,2,3,4, 5,24,48, and 72 hours after treatment. For time-response curves values are also measured after 8,12,16, and 20 hours. Blood glucose is determined in 10 pi blood samples. 

For testing the V. marginalis of the rabbit ear is used. Only water soluble drug substances should be administered. Each animal receives a volume of 0.2-0.5 ml of the solution into the mechanically congested ear vein. The ear on the other side is treated with the vehicle only. An alternative method is to use extra animals for treatment with the vehicle only. The speed of injection (volume per time) should be similar to the human clinical situation. During the injection and after the animals have to be observed for clinical signs. In total the animals have to be checked for a period of 14 days. The site of injection has to be checked for signs of local reactions. 

Basically, the pyrogen test involves measuring the rectal temperature of rabbits, both prior to and after the intravenous injection of a test solution in the ear veins. If the animals exhibit febrile responses that exceed established limits, the test solution is judged to be pyrogenic. Rabbits became the animal of choice because they are relatively inexpensive, are easy to handle, and have a labile thermoregulatory mechanism. Rabbits frequently produce false-positive pyrogen... 

Pyrogens are generally assessed using rabbits which are stored in carefully controlled conditions and whose temperature is monitored before the administration of the test product. The British Pharmacopoeia (2002) describes a test initially based on three rabbits the number is progressively increased if the product fails at any one of four stages (Table 19.4). Samples of the product under test are injected into the marginal ear vein at a dose no greater than... 

Continue anesthesia to effect with a 1 8 diluted Nembutal infusion via an indwelling marginal ear vein i.v. infusion set at approximately 20-25 mg/h. 

Phlebitis refers to inflammation of the vein wall. It can result in clinical symptoms such as pain and oedema, and can cause thrombus formation which may have serious consequences. Particulate matter is the most widely implicated cause of phlebitis. It is not surprising, therefore, that a link has been proposed between precipitation and phlebitis. The in vitro precipitation models described above may therefore be a good indicator of the phlebitic potential of a formulation. Phlebitis can be tested in vivo, usually by means of a rabbit ear vein model in which the test ear is visually compared with the control ear. 

Drawing blood from the ear vein of the rabbit is an uncomfortable business. In inexperienced hands, and under unhappy circumstances, it can lead to the death of the antibody donator (the neck is an especially sensitive part of the rabbit). The experimenter shaves a site around the ear vein, clamps the other ear vein, disinfects the shaved site with 70% alcohol, and cuts the vein with a sterile scalpel at a 45-degree angle. He catches the exiting blood (20 to 30 ml) in a 50-ml glass tube. 

Repeat the injections at 3-4 wk intervals and take blood samples 7 d after the second and subsequent injections. For rabbits, collect blood from the rear marginal ear vein. 

Inject this mixture into the rear marginal ear vein of rabbits (see Note 5). 

The use of a large dose of anesthetic ensures that the process of anesthesia is very rapid, reducing the potential period of anoxia that might otherwise be encountered If possible (e.g., in the case of rabbits, which have large accessible ear veins), it is preferable to give the anesthetic intravenously because this results in extremely rapid induction of anesthesia. 

Serum Lipid Analysis. Blood samples were withdrawn from the marginal ear-vein after overnight food deprivation every 2 wk until the termination of the experimental periods. Total cholesterol, high density lipoprotein cholesterol (HDL-C), and tri-acylglycerol (TG) concentrations were determined using enzymatic methods. Low density lipoprotein cholesterol (LDL-C) was calculated according to Friedewald et al. (14). 

Five male albino rabbits weighing 2.0-2.5 kg were used at intervals of more than two weeks. They were fasted for 1 day prior to drug administrations. HCFU or its CyD complexes as a 100 mesh powder were administered orally (15 mg/kg as equivalent of HCFU) as a suspension in 80 ml water, using a stomach catheter. Blood samples (1.5 ml) were taken from the ear vein at 0.25, 0.50, 1, 1.5, 2, 4, 6, and 8 hour after the oral administrations. The blood samples were then centrifuged (10000 rpm, 3 min), and the serum was stored in the refrigerator until assayed. 

The experimental conditions and the injection procedure were essentially the same as those in the irritation studies. Blood samples were collected from the ear vein at appropriate time intervals following treatment and centrifuged to obtain the serum for analysis. The extraction procedure of CPZ in the serum was performed according to the modified method of Mckay et al. (8). The quantification of CPZ was carried out on a gas chromatograph-mass spectrometer-computer system. The instrument was used in the selected ion monitoring mode. 

Gardner et al. (1944) produced massive fibrosis in the liver by 20 intravenous injections of powdered quartz (1-3 pm total dose 500 mg) suspended in saline into the ear veins of rabbits. When the quartz... 

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