The authors investigated the high affinity binding of [3H] muscimol to the receptor of synaptic plasma membranes (SPM) isolated from a normoxic and ischemic brain. Brain ischemia enhanced the [3H] muscimol binding to the receptor, located in native (Triton X-100 untreated) membranes. Scatchard's analysis showed that the total number of binding sites (BMAX) and the KD value increased by about 60...

We have previously described several receptors on the chondrocyte membrane. In an attempt to further characterize the coupling mechanisms of serotoninergic receptors, here we examined the involvement of serotonin in the phospholipase A2 activity. Serotonin dose-dependently stimulated phospholipase A2. This activation enhanced collagenase type II activity and had no effect on proteoglycanase act...

The M-type phospholipase A2 receptor (PLA2R) is a target autoantigen in adult idiopathic membranous nephropathy (MN), but the prevalence of autoantibodies against PLA2R is unknown among Chinese patients with MN. Here, we measured anti-PLA2R antibody in the serum of 60 patients with idiopathic MN, 20 with lupus-associated MN, 16 with hepatitis B (HBV)-associated MN, and 10 with tumor-associated ...

Secretory phospholipase A2 (sPLA2) plays a critical role in the genesis of lung inflammation through proinflammatory eicosanoids. A previous in vitro experiment showed a possible role of cell surface receptor for sPLA2 (PLA2R) in the clearance of extracellular sPLA2. PLA2R and groups IB and X sPLA2 are expressed in the lung. This study examined a pathogenic role of PLA2R in airway inflammation ...

Phospholipid metabolism was studied in rat myocardial slices that were incubated under normoxia or hypoxia for up to 24 hours. Phospholipid degradation was prominent in hypoxic myocardium, particularly phosphatidylcholine, which markedly decreased after 24 hours of hypoxia. In contrast, lysophosphatidylcholine increased. The mechanism of phospholipid degradation in hypoxic myocardium was studie...

Human milk fat globules were used to explore how dietary triglycerides are hydrolyzed by pancreatic lipase. These triglycerides were hydrolyzed very slowly by lipase alone as if the surface layer of proteins and phospholipids impeded the action of the enzyme. The inhibition of lipase activity could be overcome by addition either of colipase or of pancreatic phospholipase A2. Colipase enhanced t...

The effects of membrane sterol level on the susceptibility of LM cell plasma membranes to exogenous phospholipases A2 has been investigated. Isolated plasma membranes, containing normal or decreased sterol content, were prepared from mutant LM cell sterol auxotrophs. beta-Bungarotoxin-catalyzed hydrolysis of both endogenous phospholipids and phospholipids introduced into the membranes with beef...

Lipoprotein(a) [Lp(a)] plays an important role in atherosclerosis. The biological effects of Lp(a) have been attributed either to apolipoprotein(a) or to its low-density lipoprotein-like particle. Lp(a) contains platelet-activating factor acetylhydrolase, an enzyme that exhibits a Ca2+-independent phospholipase A2 activity and is complexed to lipoproteins in plasma; thus, it is also referred to...