LEUCINE-ENKEPHALIN AND METHIONINE-ENKEPHALIN PRODUCE OPPOSING EFFECTS ON PLASMA CORTICOSTERONE LEVELS IN ETHER-STRESSED MICE

Methionine-enkephalin and leucine-enkephalin in human sympathoadrenal system and pheochromocytoma.

To elucidate the physiological and pathophysiological significance of methionine- and leucine-enkephalin (Met-and Leu-enkephalin, respectively) in human sympathoadrenal system, the contents of these peptides in normal human sympathetic nervous system, adrenal medulla, and pheochromocytomas were determined by specific radioimmunoassays combined with reverse-phase high-performance liquid chromato...

In vitro release of [5-methionine]enkephalin and [5-leucine]-enkephalin from the rat globus pallidus.

Endogenous [5-methionine]enkephalin (Metenkephalin) and [5-leucine]enkephalin (Leu-enkephalin) are released from perfused slices of rat globus pallidus by increased K(+) in a Ca(2+)-dependent manner. Tissue perfused for 40 min contained only 26% of the Met-enkephalin and 44% of the Leu-enkephalin found in the freshly dissected tissue. After perfusion, the mean (+/-SEM) ratio (wt/wt) of Met-enke...

Plasma methionine enkephalin concentration and prognosis in primary biliary cirrhosis.

Plasma leucine enkephalin is increased in liver disease.

Plasma methionine enkephalin is increased in liver disease and may contribute to some of the clinical manifestations of hepatic failure. To determine if another 'small' opioid peptide is increased in the plasma of patients with liver disease, leucine enkephalin was measured by radioimmunoassay. Its plasma concentration was raised approximately five-fold in patients with acute liver disease (med...

Trauma decreases leucine enkephalin hydrolysis in human plasma.

Plasma hydrolysis of leucine enkephalin was evaluated, together with several cellular immune parameters, in a homogeneous group of human subjects who had undergone severe trauma (proximal femur fracture); data obtained were compared with those obtained in an age-matched control group. In the experimental group, immediately after hospitalization, substrate hydrolysis was reduced with respect bot...