Peripheral Noradrenergic Activity Research Articles

Norepinephrine and MHPG levels in CSF and plasma in Alzheimer's disease.

Postmortem findings of decreased brain norepinephrine (NE) content and decreased locus ceruleus neuronal density have suggested a possible noradrenergic deficit in Alzheimer's disease (AD). We assessed CNS and peripheral noradrenergic function in patients with advanced AD, moderate AD, and age-matched normals by measuring NE and the NE metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG) levels in CSF and plasma. Subjects were drug free for at least two weeks. Plasma and CSF NE and MHPG levels were significantly higher in patients with advanced AD than in either patients with moderate AD or normal controls, while values in the patients with moderate AD did not differ from those in normal controls. These findings do not support either a central or peripheral noradrenergic deficit in AD. Rather, they suggest increased CNS and peripheral noradrenergic activity in advanced stages of the disease.

Effect of high and low sodium intake on norepinephrine turnover in the cardiovascular tissues and brain stem of the rabbit.

To assess the relationship between sympathetic nerve function and sodium intake, we examined norepinephrine (NE) turnover in several cardiovascular tissues and the brain stem of rabbits maintained for 3 weeks on high (86 mEQ), normal (14 mEQ), and low (0.2 mEQ/day) sodium diet. None of the diets changed the blood pressure significantly. Plasma renin activity became high in the low sodium group and low in the high sodium group at the end of the treatment. NE turnover was measured from the rate of decline of tissue NE concentration after administration of alpha-methyl-p-tyrosine. Variation of sodium intake exerted opposite effects on NE turnover in the periphery and in the central nervous system; increasing sodium intake caused an increase in NE turnover in the thoracic aorta, mesenteric vein, and left ventricle, and a decrease in the hypothalamus, midbrain, and pons medulla. But in the mesenteric vein, and left ventricle, and a decrease in the hypothalamus, midbrain, and pons medulla. But in the mesenteric artery and abdominal aorta it was not affected by dietary sodium manipulation. The results show the varying influence of sodium balance on the central and peripheral noradrenergic neuron activity.

Dissociation between central and peripheral noradrenergic activity in essential hypertension.

1. Eleven patients with essential hypertension and nine healthy normotensive volunteer subjects, all without a neurological disorder, had blood drawn and cerebrospinal fluid sampled for analysis of noradrenaline (NA). 2. Cerebrospinal fluid NA levels were elevated (P < 0.01) in the hypertensive patients but plasma levels of NA were similar between groups. 3. The results suggest there is noradrenergic hyperactivity in the central nervous system which is not reflected in abnormal peripheral sympathetic nervous system function in this group of patients.

Decreased Urinary Free Catecholamines in Childhood Autism

Urinary free catecholamines were reduced in a group of boys with childhood autism when compared to normal boys of similar age. This may reflect a difference in brain and peripheral noradrenergic activity in autistic children, and is a possible correlate of altered modulation of attention, arousal, and anxiety.