The 5-HT receptor subtype was shown to be one of the principal mediators through which serotonin exert its anorectic effects in rodents by using pharmacological and genetic tools.

The psychoactive compound tetrahydrocannabinol (THC) was found to be the principal mediator of the effects of cannabis.

"This is the closest that any process has ever come to a negotiated revolution,"said the United Nations' principal mediator, Alvaro de Soto.

Bishop Ruiz has been the principal mediator between the rebels and the Government.

Talks between the Government and the rebels have continued since early Saturday, with an Anglican churchman, Canon Knolly Clarke, acting as the principal mediator.

William McChesney Martin, then Assistant Secretary of the Treasury, was the principal mediator.

Systemic heparin does not completely prevent clotting or the activation of complement, neutrophils, and monocytes, which are the principal mediators of the inflammatory response.

Gram-negative infections in MODS patients are relatively common, hence endotoxins have been advanced as principal mediator in this disorder.

A6 The Iraqi Islamic Party has emerged out of the violence in Falluja as one of the principal mediators.

Americans have known this ever since they became the principal mediators in the conflict.