Complement-mediated production of plasma-membrane vesicles from rat fat-cells

Area of Science:

• Cell Biology
• Biochemistry
• Immunology

Background:

• Rat fat cells were utilized to study plasma membrane behavior.
• Antibody and complement treatment were employed to induce cell lysis.

Purpose of the Study:

• To investigate the fragmentation of the plasma membrane following complement-mediated lysis.
• To characterize the composition of plasma membrane-derived vesicles.

Main Methods:

• Rat fat cells were treated with antibodies and guinea-pig serum to induce lysis.
• Differential centrifugation and sucrose density gradient fractionation were used to isolate membrane fragments.
• Plasma membrane markers (5'-nucleotidase, adenylate cyclase, immunoglobulin G) were analyzed.

Main Results:

• Complement-mediated lysis led to >95% release of lactate dehydrogenase, indicating significant cell membrane damage.
• Approximately 50% of plasma membrane markers remained associated with triacylglycerol.
• Sucrose density gradient centrifugation yielded two distinct vesicle fractions from the plasma membrane.

Conclusions:

• Complement-mediated lysis of rat fat cells produces plasma membrane vesicles.
• These vesicles exhibit compositional differences compared to the intact plasma membrane.