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M Sautel

Publications and source records attributed to M Sautel.

25 records · Page 2Linked to original sources
PubMed1987

Chronic treatment of the spontaneously hypertensive rat with captopril attenuates responses to noradrenaline in vivo but not in vitro.

We have studied the attenuation by captopril of sympathetic neurotransmission in spontaneously hypertensive rats. Captopril (4 mg/kg for 15-17 days or 20 mg/kg for 4 days) was delivered i.v. by osmotic minipump. The higher dose lowered blood pressure, the lower dose did not. Both doses inhibited converting enzyme activity. In the pithed rat, both doses attenuated responses to exogenous noradrenaline and sympathetic nerve stimulation. In isolated tail arteries removed from captopril-treated rats, responses to sympathetic nerve stimulation and exogenous noradrenaline were the same as in controls. Perfusion of the tail artery of control rats with captopril, angiotensin I or angiotensin II had no effect on basal perfusion pressure or on vasoconstriction induced by exogenous noradrenaline or sympathetic nerve stimulation. Our results are consistent with the hypothesis that: 1. the attenuation of sympathetic neurotransmission by captopril depends upon the presence of an intact renin-angiotensin system, and 2. captopril has no direct postsynaptic effect in the isolated tail artery preparation.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1987

Noradrenaline inhibits vasoconstriction induced by electrical stimulation.

Exposure of the isolated rat tail artery to exogenous noradrenaline inhibited vasoconstriction induced by electrical field stimulation. Phenylephrine produced brief inhibition; guanfacine potentiated electrical stimulation. Sympathetic neurotransmission may be blunted by brief increases in circulating noradrenaline levels.

Animals↗
PubMed1985

Catecholamine concentrations in discrete brain nuclei and sympathetic tissues of genetically hypertensive mice.

Catecholamine concentrations were determined at central and peripheral level in high blood pressure (HBP), low blood pressure (LBP) and random bred (RB) mice. In HBP mice compared to LBP, the noradrenaline concentration was lower in the locus coeruleus, medullary A1-C1 and A2-C2 areas, thoracic spinal cord, posteroventral hypothalamus and nucleus hypothalamicus anterior, while dopamine concentration was decreased in the striatum. Adrenal catecholamine levels were higher in both HBP and LBP compared to RB mice.

Adrenal Medulla↗
PubMed1985

Brain, spinal cord and adrenal catecholamine concentrations in neonate rats of the Lyon hypertensive strain.

The catecholamine concentrations were determined in brain parts, spinal cord and adrenals of neonate hypertensive rats of the Lyon strain (LH), compared to normotensive (LN) and low-blood-pressure (LL) control rats. In adrenals of LH rats, noradrenaline and adrenaline concentrations are increased, and 3,4-dihydroxyphenylacetic acid (DOPAC) concentration decreased. At the central level, the DOPAC concentration and the ratio DOPAC/dopamine are decreased in the mesencephalon and the forebrain of LH rats. These results suggest that neonate LH rats exhibit a decreased activity in central dopaminergic neurons, and an enhanced maturation of the adrenals.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1985

[Central and peripheral catecholamines in the genetically hypertensive mouse].

The aim of this work was to assess if biochemical alterations are present in catecholaminergic neurons of genetically hypertensive mice (HBP strain) compared to genetically hypotensive mice (LBP strain), as well as to mice of the population (R) from which HBP and LBP strains have been selected. For that purpose, dopamine (DA), noradrenaline (NA) and adrenaline (A) concentrations were determined by high performance liquid chromatography with electrochemical detection, in peripheral structures and brain nuclei of adult male mice from these three strains. In the adrenal medulla of HBP mice, DA, NA and A concentrations are increased when compared to R, but not to LBP mice. In the superior cervical ganglia of HBP mice, the NA concentration is decreased when compared to LBP, but increased when compared to R mice. At the central level, the NA concentration is decreased in HBP mice when compared to LBP, but not significantly changed when compared to R mice, in the following regions: locus coeruleus (-39 p. 100, p less than 0.001), A1-C1 (-17 p. 100, p less than 0.001) and A2-C2 (-19 p. 100, p less than 0.001) areas of the medulla oblongata, thoracic spinal cord (-26 p. 100, p less than 0.01), posteroventral hypothalamus (-18 p. 100, p less than 0.01) and nucleus hypothalamicus anterior (-14 p. 100, p less than 0.01). In the nucleus periventricularis, NA concentration of HBP mice is not changed when compared to both LBP and R animals. Finally, in the caudate nucleus of HBP mice, the DA concentration is decreased when compared to both R and LBP mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Medulla↗