Ultrastructural localization of apo-b and apo-c binding to very low density lipoproteins in rat liver.

Hepatic synthesis of apo-B and apo-C and their binding to nascent very low density lipoproteins (VLDL) have been studied in fat-fed rats. Apolipoproteins were located in hepatocyte organelles by light and electron microscopy after immunoenzymatic staining using peroxidase-conjugated antibodies. Our results indicate that apo-B and apo-C are synthesized by membrane-bound ribosomes. Both apoproteins seem to be adsorbed simultaneously to the lipid core of VLDL in the lumen of the endoplasmic reticulum channels, at the junction zone between rough and smooth endoplasmic reticulum. Some additional protein presumably binds nascent VLDL in the Golgi apparatus as judged by the strong positive reaction of lipoprotein particles with peroxidase-labeled antibodies. Finally our data show that significant amounts of apo-B and apo-C are bound to the sinusoidal plasma membrane in fed rat livers which probably represent remnants of lipoprotein of intestinal origin since membrane-bound apolipoproteins virtually disappeared 24 h after lymphatic duct cannulation. It is suggested that nascent VLDL (apo-C poor) could be enriched in apo-C from lipoprotein remnants at the space of Disse.     

Morphological and physiological plasticity of Saccharina latissima (Phaeophyceae) in response to different hydrodynamic conditions and nutrient availability

Journal of Applied Phycology - Morphology and physiology are two key aspects of the adaptation of kelp to varying environments. Some of these kelp responses to co-occurring highly hydrodynamic...     

A mechanism of erythrocyte lysis by lysophosphatidylcholine.

Lysophosphatidylcholine micelles liberate several cell surface polypeptides from erythrocyte membranes, inducing a sodium-selective permeability defect which leads to colloid osmotic lysis. Evidence is presented to support the hypothesis that at the lowest lytic lysophospholipid concentrations, selective disruption of membrane protein function, rather than gross structural reorganization of the membrane, is the primary lytic mechanism.     

Seagrass Sensitivity to Collapse Along a Hydrodynamic Gradient: Evidence from a Pristine Subtropical Intertidal Ecosystem

Ecosystems - Eutrophication causes tremendous losses to seagrass around the globe. The effects of nutrient loading vary along environmental gradients, and wave forces especially are expected to...