Inhibition of functional vasodilatation and prostaglandin formation in rabbit adipose tissue by indomethacin and aspirin.

1. The epigastric adipose depot of rabbits has been used to examine the effect of indomethacin, aspirin and nicotinic acid on the free fatty acid release and blood flow in fat tissue.2. The prostaglandin formation which occurs in adipose tissue during lipolysis is prevented by indomethacin and aspirin. The corresponding functional vasodilatation which occurs after infusions of lipolytic substances is also abolished by these two anti-inflammatory compounds.3. This finding is consistent with the theory that prostaglandin E(2) is the mediator of functional vasodilatation in adipose tissue.4. Nicotinic acid sometimes inhibits the release of free fatty acids from adipose tissue by preventing activation of the tissue lipase. In those experiments in which this inhibition occurred, the vasodilatation was also prevented.5. This finding is consistent with the view that the prostaglandin E(2) which mediates the functional vasodilatation, originates in the triglycerides of the fat tissue.