Pharmacokinetic and Pharmacodynamic Investigations of ION-353382, a Model Antisense Oligonucleotide: Using Alpha-2-Macroglobulin and Murinoglobulin Double-Knockout Mice.

To investigate the pharmacokinetics (PKs) and pharmacodynamics (PDs) for ION-353382, an antisense oligonucleotide (ASO) targeting scavenger receptor class B type I (SRB1) mRNA, using alpha-2-macroglobulin (A2M), murinoglobulin double-knockout (DKO), and wild-type mice. Wild-type and DKO homozygous mice were administered a single subcutaneous injection of ION-353382 at 0, 5, 15, 30, and 60 mg/kg. Mice were sacrificed at 72 h with plasma and organs harvested. Both liquid chromatography-mass spectrometry (LC-MS) and enzyme-linked immunosorbent assay (ELISA) were used to determine ASO exposure with real-time PCR for SRB1 expression. Immunohistochemistry was evaluated to explore hepatic uptake of ASOs. The total plasma protein binding and profiling was assessed. Finally, two-dimensional gel electrophoresis identified protein expression differences. PK exposures were comparable between wild-type and DKO mice in plasma, liver, and kidney, yet a near twofold reduction in EC50 was revealed for DKO mice based on an inhibitory effect liver exposure response model. Total plasma protein binding and profiling revealed no major dissimilarities between both groups. Plasma proteome fingerprinting confirmed protein expression variations related to A2M. Histological examination revealed enhanced ASO distribution into hepatocytes and less nonparenchymal uptake for DKO mice compared to wild-type mice. Knocking out A2M showed improved PD activities without an effect on total plasma and tissue exposure kinetics. Binding to A2M could mediate ASOs to nonproductive compartments, and thus, decreased binding of ASOs to A2M could potentially improve ASO pharmacology.

Conglutinin exhibits a complement-dependent enhancement of the respiratory burst of phagocytes stimulated by E. coli.

Conglutinin is a mammalian C-type lectin which shows anti-bacterial activity when tested in vivo and in vitro. This study concerns the effect of conglutinin on the respiratory burst of murine spleen cells, using a chemiluminescence assay for measurement of generated reactive oxygen metabolites. Conglutinin enhances, in a dose-dependent manner, the respiratory burst of spleen cells stimulated with serum-opsonized Escherichia coli. The enhancement was only demonstrable in the presence of a functional complement system. The conglutinin-mediated enhancement of the respiratory burst was inhibited in the presence of a N-acetyl-D-glucosamine, D-mannose and N-acetyl-D-mannosamine, monosaccharides reported to inhibit conglutinin-binding to zymosan and the complement factor iC3b. On the other hand, N-acetyl-D-galactosamine was non-inhibitory.

[Effect of alcohols and the products of their oxidation on the fibrinolytic activity of euglobulins]. / Wplyw alkoholi i produktów ich utleniania na aktywnosc fibrynolityczna euglobulin.

Aldehydes (formaldehyde and acetaldehyde) inhibit the fibrinolytic, caseinolytic and amidolytic activity of blood plasma euglobulins. Alcohols (methanol, ethanol, propanol and iso-propanol) and sodium salts of organic acids (formate, acetate and propionate) show inhibitory activity towards the fibrinolytic activity of euglobulins only at small degree and at high concentrations.

Intrinsic plasma fibrinolysis: involvement of urokinase-related activity in the factor XII-independent plasminogen proactivator pathway.

A portion of human blood fibrinolytic activity can be quenched by antibodies to urokinase. We attempted to identify this portion and its position in the three pathways (extrinsic, intrinsic factor XII dependent, and intrinsic factor XII independent) of plasminogen activator activity that have been defined in the DEFs of plasma. Activity quenching in various plasmas (including plasma adsorbed by agarose-bound AUK) demonstrated the involvement of a discrete activator activity of 40 to 50 BAU/ml with little variation among individuals (43 +/- 6 (SD) BAU/ml, n = 13). The quenching did not involve, quantitatively or qualitatively, the extrinsic (tissue-type) plasminogen activator activity varying between 1 and 146 BAU/ml in baseline plasma and in plasma obtained after stimulation by venous occlusion, exercise, or DDAVP administration. In confirmation, extrinsic activator activity was recovered in plasma adsorbed by agarose-bound AUK. The quenching also did not involve the factor XII-dependent activities; it was quantitatively normal in plasma with Hageman (n = 3) and Fletcher (n = 2) traits, and AUK did not interfere with the generation of factor XII-dependent fibrinolytic activity by addition of purified activated factor XII in plasma with Hageman trait. There was no effect of AUK on kallikrein generation, kallikrein activities, or the APPT, nor were these aspects altered in depleted plasma. In conclusion, the quenching involved the factor XII-independent system of intrinsic fibrinolysis. Addition of purified urinary urokinase did not result in restoration of missing activity in plasma adsorbed by AUK-agarose. The quenching, therefore, probably involved an apparent urokinase-related activator component in plasma.

Prevention of the abortifacient action of antiprogesterone serum by progesterone.

Earlier studies1-4 showed that when rats of 10 days' gestation are passively immunized with antiprogesterone (A-P) globulins the biologically available progesterone (P) unbound by A-P (Pu) not only falls precipitously but also remains low for days, despite the rapid clearance of A-P. This finding suggested that the effective reduction of Pu affects P synthesis, probably through action on the fetoplacental unit. If so, pregnancy should be protected from the effect of A-P by P treatment to prevent the reduction of Pu. The present studies demonstrated that if P treatment was delayed for six hours after the administration of A-P, Pu did not return to physiologic levels, and pregnancy did not continue. However, if P was given three hours after A-P, at the same time, or three hours before A-P, the reduction of Pu was short-lived or prevented, and thus pregnancy was protected.

PIP: It has previously been shown that passive immunization of 10-day pregnant rats with antiprogesterone (AP) globulins dramatically reduces the amount of available progesterone (P) unbound (Pu) to AP, even though AP is rapidly removed. In the present study with pregnant rats, it was shown that treatment with P no earlier than 6 hours after administration of AP on Day 10 of pregnancy did not return Pu levels to the normal range, and resulted in termination of pregnancy. However, if P was administered within 3 hours before or after administration of AP, the loss of Pu was transitory or prevented, and pregnancy was maintained.