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Biomedical subjects

B Renaud

Publications and source records attributed to B Renaud.

At least 127 records · Page 7Linked to original sources
PubMed1978

Early increase in phenylethanolamine-N-methyltransferase activity in a new strain of spontaneously hypertensive rats.

By repeated inbreeding, 2 strains of spontaneously hypertensive and normotensive rats have been simultaneously selected. The activities of tyrosine hydroxylase and phenylethanolamine-N-methyltransferase were determined in various central catecholaminergic nuclei (C1, C2, A6 and A9) and in two peripheral tissues (adrenal glands and superior cervical ganglion). These assays were performed on rats belonging to the normotensive or the hypertensive strain at 3 ages which characterize the development of hypertension (5, 9 and 21 weeks). Except for a decrease in the C1 region of 9-week-old rats, no significant change in tyrosine hydroxylase activity occurred in central or peripheral structures of the spontaneously hypertensive rats when compared to the normotensive rats. In contrast, the activity of the phenylethanolamine-N-methyltransferase (PNMT), was increased in the C2 adrenergic group of the medulla oblongata in young spontaneously hypertensive rats: +43% (P less than 0.001) at 5 weeks of age and +32% (P less than 0.001) in 9-week-old rats. However, there was no significant difference between the 21-week-old rats. No modification of the PNMT activity was found in the C1 adrenergic group of the medulla oblongata. PNMT activity was increased significantly in the adrenal glands of 5-week-old hypertensive rats (+22%, P less than 0.001). By 9 weeks, the difference in PNMT activity in the adrenals was no longer significant. Thus, in young rats of the hypertensive strain, there was an increase in the capacity to synthetize adrenaline in the C2 area of the medulla oblongata and in the adrenal glands. While the enzymatic change present in the adrenals seems to be specific to this new strain of hypertensive rats, the elevation of PNMT activity in a specific region of the medulla oblongata (C2 group) is a characteristic common to at least two independently derived strains of genetically hypertensive rats.

Adrenal Glands↗
PubMed1978

[Monoamine metabolites and cyclic nucleotides in the cerebrospinal fluid of patients with bismuth or mercury poisoning].

The central metabolism of dopamine, serotonin, cyclic AMP and cyclic GMP was studied by use of the probenecid test in three patients with bismuth encephalopathy and in one patient with mercury encephalopathy. The accumulation of HVA and of cGMP in the cerebrospinal fluid was depressed during the acute phase of bismuth encephalopathy with severe hyposomnia, while it was increased in a patient with regression of clinical symptoms and normal in a patient with more advanced recovery. The patient with chronic mercury poisoning showing a severe cerebellar ataxia and rigidity had an almost complete suppression of HVA accumulation and an increase of cGMP accumulation. No pronounced differences of 5-HIAA and cAMP behavior were found. It is concluded that the central metabolism of dopamine and of cGMP is severely affected in bismuth and mercury encephalopathies.

Adult↗
PubMed1978

Biogenic amines in 47, XYY syndrome.

47, XYYs represent a high percentage of patients admitted in security settings for aggressiveness. By using a polygraphic technique and amine metabolite estimation in the cerebrospinal fluid (CSF), an attempt was made to evaluate the functional activity of the central aminergic system of these patients. No drastic change was observed in sleep patterns of XYYs. The estimation of CSF amine metabolites revealed a normal value for homovanillic acid, but a significant decrease of 5-hydroxyindoleacetic acid turnover.

Adult↗
PubMed1976

Time-course variations in tyrosine hydroxylase activity in the rat locus coeruleus after electrolytic destruction of the nuclei raphe dorsalis or raphe centralis.

Time-course variations in tyrosine hydroxylase activity were measured in the locus coeruleus of the albino rat after electrolytic coagulation of either the nucleus raphe dorsalis or the nucleus raphe centralis. Highly significant increases were measured at 4 days after lesioning of the raphe dorsalis (30.33%) and the raphe centralis (81.55%) compared with control values, whereas the activity in groups A9 and A10 was unchanged at this time-point. In conjunction with other experimental evidences, an hypothesis is proposed that the catecholaminergic neurons located in the locus coeruleus are directly and/or indirectly controlled by the serotonin-containing neurons located in the anterior raphe system nuclei.

Animals↗
PubMed1976

[Cerebral metabolism of dopamine and of serotonin during Alzheimer and Pick's diseases. Dynamic study by the test using probenecid].

A study of the cerebral metabolism of dopamine and serotonin has been realized by the probenecid test in 17 patients. The diagnosis of Alzheimer's disease (13 patients) and Pick's disease (4 patients) has been made on clinical and radiological grounds. No important anomaly of this metabolism was discovered. In subjects with Alzheimer's disease, the renewal rates of H.V.A. and 5 H.I.A.A. were diminished in comparison to the values measured in normal individuals, but this difference was not significant. In patients with Pick's disease, the accumulation of H.V.A. after probenecid was in the normal bounds, whereas that of 5 H.I.A.A. was non-significantly decreased. The results are compared with those of the literature.

Aged↗