[Relationship between thromboplastin activity in different brain structures and the quantitative interrelationships of functionally different groups of phospholipids in them].

The microsomal fraction of rabbit brain has the highest content of phospholipids and is completely devoid of polyglycerophospholipids. The decrease of the ratio of neutral to acid phospholipids is accompanied by a corresponding reduction of thromboplastic activity. Thromboplastic activity is high in the nuclear fraction of the medulla oblongata, cerebellum and cerebral hemispheres. Adrenaline reduces the amount of both total and individual phospholipids (mainly neutral) in subcellular particles of brain. This is accompanied by reduction of thromboplastic activity. The incubation of homogenates of brain parts for 2 hrs in the presence of glucose brings to the increase of phospholipids in the incubation medium and enhancement of thromboplastic activity.