Since volcanic eruptions are caused by magma (a mixture of liquid rock, crystals, and dissolved gas) expelled onto the Earth's surface, we must first discuss the characteristics of magma and how magmas form in the Earth. Characteristics of Magma. Types of Magma Types of magma are determined by chemical composition of the magma.
Normetanephrine is a metabolite of norepinephrine created by action of catechol-O-methyl transferase on norepinephrine.It is excreted in the urine and found in certain tissues. It is a marker for catecholamine-secreting tumors such as pheochromocytoma.ormetanephrine is a metabolite of norepinephrine created by action of catechol-O-methyl transferase on norepinephrine.
In particular, despite consistently high plasma concentrations of normetanephrine or metanephrine, some patients with pheochromocytoma have normal plasma concentrations of catecholamines or have high concentrations only during paroxysmal attacks.wo patients with von HippelâLindau disease and all patients with MEN-2 who had pheochromocytoma also had high plasma concentrations of metanephrine; thus, both plasma normetanephrine and metanephrine were normal in only 1 of the 38 tests in the 35 patients with familial pheochromocytoma.