Browsing by Subject "plasma"

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Aging Systemic Milieu Impairs Outcome after Ischemic Stroke in Rats
(JKL International, 2017-10-01) Pan, Mengxiong; Wang, Peng; Zheng, Chengcai; Zhang, Hongxia; Lin, Siyang; Shao, Bei; Zhuge, Qichuan; Jin, Kunlin
Compelling evidence indicates that factors in the blood can profoundly reverse aging-related impairments, as exposure of aged mice to young blood rejuvenates adult stem cell function, improves cognition, and ameliorates cardiac hypertrophy. Systemic factors from mice can also extend the life span of a partner exposed to a lethal treatment or disease. These findings suggest that the systemic milieu of a healthy young partner may be beneficial for an aged organism. However, it is unknown whether a healthy young systemic milieu can improve functional recovery after ischemic stroke. Intraperitoneal administration of young plasma into aged rats after ischemic stroke induced by distal middle cerebral artery occlusion (dMCAO) reduced infarct volume and motor impairment, compared with vehicle group. On the contrary, intraperitoneal administration of plasma from aged rats into young ischemic rats worsened brain injury and motor deficits. Using a proteomic approach, we found that haptoglobin levels were significantly increased in serum of aged rats and that intraperitoneal administration of haptoglobin impaired outcome after ischemic stroke in young rats. Our data suggest that the aging systemic milieu plays a critical role in functional outcome after ischemic stroke.
Horse Serum High Density Lipoproteins as Drug Transporters
(2004-05-01) Johnson, Shemedia; Walter McConathy
Johnson, Shemedia J., Horse Serum High Density Lipoproteins (HDL) as Drug Transporters. High-density lipoproteins (HDL) are complex particles composed of specific proteins and lipids that facilitate blood and tissue cholesterol homeostasis by transporting excess peripheral cholesterol to the liver. In association with cholesterol ester transfer protein (CETP) and the enzyme, lecithin: cholesterol acyltransferase (LCAT), HDL contributes to the transport of hydrophobic lipids, including cholesterol ester and triglycerides through the blood. The studies presented here involve the evaluation of horse serum HDL as a carrier of water insoluble drugs and an improved process to isolate and purify horse serum HDL utilizing hydrophobic affinity chromatography. Dilauryl fluorescein (DLF) has been chosen as a model compound for the study of horse HDL as a drug carrier. The prepared HDL/DLF particles have similar flotation densities and size properties to native horse serum HDL. The amount of DLF incorporated into HDL is 30μg/mg protein. Various cancer cell lines internalized DLF from horse HDL/DLF particles successfully. While human plasma contains cholesterol ester transfer protein (CETP), horse plasma does not. Horse plasma/serum can be supplemented by human plasma to study the role of CETP in drug transport and the stability of the horse HDL/drug complex.
Met-Enkephalin-Arg-Phe (MERF) and Metabolism of MERF Across the Canine Heart Vascular Bed
(2000-08-01) Pearlman, Eric Brian; Barron, Barbara; Gwirtz, Patricia A.; Smith, Michael L.
Pearlman, Eric B., Met-Enkephalin-Arg-Phe (MERF) and Metabolism of MERF Across the Canine Heart Vascular Bed. Master of Science (Biomedical Science), August, 2000, 37 pp., 3 tables, 11 figures, references, 20 titles. Methionine enkephalin arginine phenylalanine (MERF) has been shown to be co-stored with catecholamines in vesicles. The catecholamines appear to decrease the degradation rate of 3H-MERF in vitro. The aim of this study is to investigate the spillover and metabolism of MERF across the canine heart vascular bed. I hypothesize that 3H-MERF is either degraded in the plasma or taken up and degraded by the heart. I further hypothesize that the exogenous catecholamine, isoproterenol, inhibits or reduces the rate of MERF degradation. Mongrel dogs were anesthetized and instrumented to record cardiovascular parameters, infuse 3H-MERF, and obtain blood samples across the heart. Blood samples were taken before and after stopping 3H-MERF infusion to evaluate kinetics, show steady state, and test the effect of treatments. Steady state concentration of 3H-MERF was observed after 30 min of infusion. Chromatography separated intact from degraded 3H-MERF. Three experimental groups were used: control, propranolol plus isoproterenol, and propranolol only. Blockade of β-receptors was necessary to prevent changes in coronary blood flow. Propranolol bolus (0.2 mg/kg) was administered IV at 50 min. 3 μg/min isoproterenol or 0.5 ml/min normal saline was infused starting at 70 min until the end of sample collection. The 3H-MERF venous-arterial (V-A) difference prior to treatment was negative, indicating degradation in the plasma or uptake and degradation by the heart. The 75 min V-A difference was used to calculate the effect of the infusions on the degradation or uptake of the 3H-MERF; this value was unchanged by any treatment. Spillover of 3H-MERF was significantly lower in the propranolol + isoproterenol dogs (p [less than] 0.05) compared to propranolol only treatment at 75 min. Heart rate was significantly lower for the propranolol only group compared to control. Blood pressure and change in coronary flow were unchanged. In conclusion, isoproterenol does not affect the metabolism of 3H-MERF across the canine heart vascular bed. Propranolol, however, does increase the intact 3H-MERF in the plasma, but additional β adrenergic blockade agents need to be investigated to determine the mechanism by which this takes place.