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Biomedical subjects

W D Rausch

Publications and source records attributed to W D Rausch.

41 records · Page 3Linked to original sources
PubMed1978

Dopamine-sensitive adenylate cyclase activity in the caudate nucleus and adrenal medulla in Parkinson's disease and in liver cirrhosis.

In human caudate nucleus and adrenal medulla dopamine-stimulated adenylate cyclase was measured. At a concentration of 100 microM dopamine, liver cirrhosis, carcinoma and therapy resistent parkinsonian patients showed decreased stimulation or even a reduction compared to controls. Therapy responding parkinsonian patients showed a decreased stimulation compared to controls, but this stimulation was significantly higher than in drug resistent patients.

Adenylyl Cyclases↗
PubMed1978

Brain monoamines in hepatic encephalopathy and other types of metabolic coma.

Tyrosine (Tyr), tyrosine hydroxylase (TH), tryptophan (Trp), serotonin (5-HT), and 5-hydroxyindole acetic acid (5-HIAA) were assayed spectrofluorometrically and radioenzymatically in various regions of post-mortem brains of human patients with hepatic, uremic, and diabetic coma, liver cirrhosis without coma, and hepatic coma treated with parenteral administration of L-valine, a branched-chain amino acid. The results were as follows: In both hepatic and diabetic coma Tyr was increased as compared to non-comatose cirrhosis and controls, while TH acitivity was within normal limits, indicating sufficient oxygen supply of the brain in both types of coma. Brain DA showed a mild decrease in all types of metabolic coma. Brain Trp was not considerably changed in non-comatose cases of liver cirrhosis and after L-valine treatment of hepatic encephalopathy, but was significantly increased in hepatic coma, with highest elevation in the brainstem tegmentum. Both 5-HT and 5-HIAA were not significantly changed in non-comatose cirrhosis, while a general increase with prevalence for the brainstem was obvious in all types of metabolic coma. After L-valine treatment of hepatic coma, 5-HT levels were usually decreased below control values, while 5-HIAA levels were at or below controls. These results in human post-mortem brains confirm previous CSF and brain findings in experimental and human hepatic and uremic encephalopathies, indicating derangement of brain monoamine neurotransmitter metabolism which is attributed to imbalance of aromatic and branched-chain amino acids in plasma and brain. Increased cerebral 5-HT turnover, particularly in the ascending serotonergic brainstem systems, due to derangement of brain uptake of Trp is suggested to represent an important biochemical substrate of disorders of consciousness in hepatic failure and other types of metabolic encephalopathies. Clinical improvement of hepatic encephalopathy and of the underlying neurotransmitter derangements by administration of L-valine and the possible role of this competitive amino acid on intermediary metabolism and ammonia detoxification are discussed.

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PubMed1978

CNS Modulation of adrenal tyrosine hydroxylase in Parkinson's disease and metabolic encephalopathies.

Tyrosine hydroxylase (TH) activity was assayed radioenzymatically in various regions of post-mortem brains of human individuals without neurologic disorders (controls), with Parkinson's disease, senile dementia, hypertensive encephalopathy, hepatic and diabetic coma, liver cirrhosis without coma, and hepatic coma treated with parenteral administration of L-valine. In addition TH activity of the post-mortem adrenal medulla was assayed in controls, in Parkinson's disease, senile dementia and hypertensive encephalopathy. In Parkinson's disease TH activity was significantly decreased in the nigrostriatal system, and less severe in other brainstem areas, while the raphé-reticular formation and limbic system showed normal values. In addition, there was significant decrease in the TH activity of the adrenal medulla, suggesting that Parkinson's disease is a generalized disorder not limited to distinct CNS areas, and that impairment of the dopaminergic niggro-striatal system may involve the TH activity in the adrenal medulla, thus inducing disorders of the peripheral sympathetic system. Senile brain atrophy showed no definite changes in brain, except the striatum, and adrenomedullary TH, while in one case of hypertensive encephalopathy due to long-term corticosteroid treatment normal TH activity in the adrenal medulla was opposed by decreased striatal TH activity, probably due to cerebral ischemia. TH activity in the caudate nucleus of individuals with both hepatic and diabetic coma were within normal ranges, suggesting a sufficient energy supply of the brain during such metabolic catastrophes, while reduced brain TH activity in patients with hepatic coma who died of acute gastrointestinal bleeding is probably due to severe final cerebral ischemia. No correlative data on brain and adrenomedullary TH activities in metabolic encephalopathies are available so far.

Aged↗