Effects of melittin on adipocyte metabolism unrelated to lysophospholipid accumulation.
Melittin addition to rat or hamster adipocytes resulted in inhibition of lipolysis, cyclic AMP accumulation and glucose oxidation. Low concentrations of melittin were not insulin-like with respect to either stimulation of glucose metabolism or inhibition of lipolysis. Higher concentrations of melittin lysed adipocytes. In the presence of melittin, cellular phospholipids were released to the medium and hydrolyzed with little accumulation of lysophospholipids. Only in adipocytes incubated with melittin contaminated with phospholipase A2 was any appreciable accumulation of lysophospholipids seen and this was in the medium. These data suggest that the toxic effects of melittin on adipocytes are not due to the accumulation of lysophospholipids but rather to the loss of membrane phospholipids or alterations in membrane proteins.
D000273:Adipose Tissue / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D001514:Bee Venoms / Q000494:pharmacology*; D006224:Cricetinae; D000242:Cyclic AMP / Q000378:metabolism; D005260:Female; D066298:In Vitro Techniques; D008066:Lipolysis / Q000187:drug effects; D008246:Lysophospholipids; D008297:Male; D008555:Melitten / Q000494:pharmacology*; D008563:Membrane Lipids / Q000378:metabolism; D008647:Mesocricetus; D010741:Phospholipases A / Q000378:metabolism; D054467:Phospholipases A2; D010743:Phospholipids / Q000378:metabolism*; D051381:Rats
D001514:Bee Venoms; D008246:Lysophospholipids; D008563:Membrane Lipids; D010743:Phospholipids; D008555:Melitten; D000242:Cyclic AMP; D010741:Phospholipases A; D054467:Phospholipases A2