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Biomedical subjects

M Fillenz

Publications and source records attributed to M Fillenz.

At least 109 records · Page 6Linked to original sources
PubMed1978

Changes in plasma noradrenaline concentration as a measure of release rate.

1 A method is described for repeated sampling of plasma noradrenaline (NA) in freely moving rats. Na concentration does not change during the day or after adrenalectomy. 2 Exogenous NA has a half-life of 1.5 min; drugs which block neuronal and extra-neuronal uptake lengthen this to 6.3 min. 3 Swim-stress leads to a steep rise followed by a rapid decline in plasma NA concentration. 4 This method of plasma NA sampling can serve as a measure of both steady and rapid changes in release rate over long periods of time.

Adrenalectomy↗
PubMed1976

Selective uptake and retrograde axonal transport of dopamine-beta-hydroxylase antibodies in peripheral adrenergic neurons.

In the present experiments the uptake and retrograde axonal transport of antibodies to dopamine beta-hydroxylase (DBH) in adrenergic neurons was studied. When partially purified labelled antibodies to DBH were injected unilaterally into the vicinity of the adrenergic nerve terminals in the iris, radioactive substances accumulated preferentially in the superior cervical ganglia of the injected. By SDS (sodium dodecyl sulfate) gel electrophoresis and immunoprecipitation it could be shown that the accumulated radioactivity in the superior cervical ganglion represented antibodies to DBH. This retrograde accumulation was greatly reduced by colchicine, axotomy or destruction of the adrenergic nerve terminals by 6-hydroxydopamine. The rate of retrograde transport was the same as that of nerve growth factor (NGF) and tetanus toxin in sympathetic neurons. The retrograde transport of antibodies was confined to sympathetic neurons and could not be detect in either sensory or motor neurons.

Animals↗
PubMed1976

Quantitative differences between sympathetic nerve terminals.

The fluorescence histochemical method for catecholamines shows differences in both innervation density and fluorescence intensity between sympathetic nerve terminals in different organs. Quantitative electron microscopy shows differences in vesicle density in varicosities of nerve terminals in heart, spleen and vas deferens of the rat. The electron-dense core of the small noradrenergic vesicles has a different mean volume and a different core-size distribution in different nerve terminals. The significance of these findings is discussed.

Animals↗
PubMed1971

The storage of endogenous noradrenaline in sympathetic nerve terminals.

1. The subcellular distribution of noradrenaline in sympathetic nerve terminals of rat vas deferens and cat spleen has been studied by cell fractionation methods combined with fluorescence and electronmicroscopic histochemical methods for noradrenaline.2. Pinched-off axon varicosities (synaptosomes) were isolated and identified by fluorescence and electronmicroscopy in the mitochondrial pellet.3. The proportion of large to small dense-cored vesicles in electronmicrographs of sympathetic nerve terminals varies in different organs. In rat vas deferens 4% and in cat spleen 20% are large vesicles.4. Density gradients of rat vas deferens have a single low density peak of noradrenaline at 0.6 M sucrose, whereas those of cat spleen have an additional peak of noradrenaline at 1.1 M sucrose.5. Small dense-cored vesicles were identified electronmicroscopically in the low density fractions and large dense-cored vesicles in the high density fractions from density gradients.6. We conclude that both small and large dense-cored vesicles store noradrenaline.

Animals↗