ZIB

1

Digitale Medien

Uptake of dopamine into fractions of pig caudate nucleus homogenates (1975)

Philippu, A. ; Matthaei, H. ; Lentzen, H.

Springer

Naunyn-Schmiedeberg's archives of pharmacology 287 (1975), S. 181-190

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1432-1912

Schlagwort(e): Caudate Nucleus ; Dopamine ; Ouabain ; Reserpine ; Prenylamine ; Uptake

Quelle: Springer Online Journal Archives 1860-2000

Thema: Medizin

Notizen: Summary Homogenates of the caudate nucleus of the pig were submitted to differential centrifugation. The 20 000 g and 80 000 g fractions were isolated and a part of them was osmotically shocked. The highest dopamine content per mg protein was found in the intact 80 000 g fraction. Incubation experiments with the intact and the osmotically shocked fractions at 25°C revealed that the particles of the intact 20 000 g fraction took up dopamine; the influx of the amine was not enhanced by addition of ATP and magnesium to the incubation medium. On the other hand after osmotic shock the uptake of dopamine into the particles of this fraction was greatly enhanced by addition of ATP and magnesium. The uptake of dopamine into the particles of both intact and osmotically shocked 80 000 g fractions was likewise enhanced by ATP and magnesium. The uptake in all fractions was not influenced by ouabain. The influx of dopamine into the particles of the intact 80 000 g fraction was competitively inhibited by reserpine (K i 0.96×10−8 M) and prenylamine (K i 1.74×10−8 M). It is concluded that the intact 20,000 g fraction contains intact synaptosomes; the uptake of dopamine is independent of the presence of ATP and magnesium. The shocked 20 000 g fraction and the 80 000 g fractions contain synaptic vesicles; the uptake of dopamine into these vesicles is enhanced by ATP and magnesium.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00510449

Permalink

Bibliothek	Standort	Signatur	Band/Heft/Jahr	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

2

Digitale Medien

Release of endogenous histamine in the hypothalamus of anaesthetized cats and conscious, freely moving rabbits (1982)

Philippu, A. ; Hanesch, U. ; Hagen, R. ; [weitere]

Springer

Naunyn-Schmiedeberg's archives of pharmacology 321 (1982), S. 282-286

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1432-1912

Schlagwort(e): Release of endogenous histamine ; Hypothalamus ; Cat ; Freely moving rabbit ; Electrical stimulation

Quelle: Springer Online Journal Archives 1860-2000

Thema: Medizin

Notizen: Summary The hypothalamus of anaesthetized cats and conscious, freely moving rabbits was superfused with CSF through double-walled, push-pull cannulae and the release of endogenous histamine was determined in the superfusates by a radioenzymatic assay. In the posterior hypothalamic area of the anaesthetized cat, the rate of release of endogenous histamine varied rhythmically; phases of high rate of release appeared at 60 min cycles. The release of histamine was increased by electrical stimulation of the superfused area, as well as by hypothalamic superfusion with potassium-rich CSF. In the conscious rabbit, the anterior hypothalamic area and the posterior hypothalamic nucleus were superfused simultaneously. In both regions, the resting release of histamine varied rhythmically at approximately 70 min cycles. Phases of high or low-rate of release in the anterior hypothalamic area coincided with the corresponding phases in the posterior hypothalamic nucleus. The rhythmic release of endogenous histamine in the hypothalamus, as well as the ability of depolarizing stimuli to enhance the release of the amine support the idea that histamine acts as a neurotransmitter in the central nervous system.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00498514

Permalink

Bibliothek	Standort	Signatur	Band/Heft/Jahr	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

3

Digitale Medien

Uptake of tyramine into synaptic vesicles of the caudate nucleus (1977)

Lentzen, H. ; Philippu, A.

Springer

Naunyn-Schmiedeberg's archives of pharmacology 300 (1977), S. 25-30

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1432-1912

Schlagwort(e): Synaptic vesicles ; Uptake ; Dopamine ; Tyramine ; Reserpine ; Filtration

Quelle: Springer Online Journal Archives 1860-2000

Thema: Medizin

Notizen: Summary Synaptic vesicles isolated from the caudate nucleus of the pig were preincubated with reserpine, serotonin or tyramine at concentrations which caused a 90% inhibition of the ATP-Mg2+-dependent uptake of 14C-dopamine. The preincubated vesicles were sedimented by centrifugation and resuspended in drug-free buffer. The vesicles were incubated with 14C-dopamine in the presence or in the absence of ATP-Mg2+; at the end of the incubation period they were separated from the incubation medium by centrifugation. The inhibitory effect of reserpine on the ATP-Mg2+-dependent uptake of 14C-dopamine was slightly diminished, that of serotonin reduced while the inhibitory effect of tyramine was abolished. Hence, tyramine seems to be more easily removable than the other substances. In another series of experiments the vesicles were incubated with 3H-tyramine and immediately separated by filtration through membrane filters. Addition of ATP-Mg2+ enhanced the uptake of 3H-tyramine. The Km of the ATP-Mg2+-dependent uptake of 3H-tyramine was 1.4×10−7 M, the Vmax 29.2 pmoles/mg protein/min. At 0°C the uptake of 3H-tyramine in the absence of ATP-Mg2+ was reduced, that in the presence of ATP-Mg2+ abolished. Incubation of the vesicles with 3H-dopamine revealed K m and V max values similar to those previously found when the vesicles were isolated from the incubation medium by centrifugation. Incubation in the presence of reserpine inhibited the ATP-Mg2+-dependent uptake of 3H-tyramine (IC50 1.4×10−8 M) and 3H-dopamine (IC50 4.1×10−8 M). The results demonstrate that tyramine is taken up into the vesicles by a process which is dependent on ATP-Mg2+ and temperature. Failure of previous attempts to prove an ATP-Mg2+-dependent uptake of tyramine when the vesicles were separated by centrifugation seems to be due to release of the accumulated tyramine during the centrifugation procedure.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00505076

Permalink

Bibliothek	Standort	Signatur	Band/Heft/Jahr	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

4

Digitale Medien

Carotid occlusion increases the release of endogenous GABA in the nucleus of the solitary tract (1989)

Klausmair, A. ; Philippu, A.

Springer

Naunyn-Schmiedeberg's archives of pharmacology 340 (1989), S. 764-766

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1432-1912

Schlagwort(e): Nucleus of the solitary tract (NTS) ; GABA release ; Carotid occlusion ; Blood pressure ; Push-pull cannula ; Cat

Quelle: Springer Online Journal Archives 1860-2000

Thema: Medizin

Notizen: Summary In anaesthetized cats, the nucleus of the solitary tract was bilaterally superfused through push-pull cannulae with artificial cerebrospinal fluid (CSF) and the effect of carotid occlusion on the release of endogenous GABA was investigated. Bilateral carotid occlusion led to a rise in blood pressure which was associated with a very pronounced increase in the release rate of GABA in the nucleus of the solitary tract. The results demonstrate the hypertensive function of GABA in the nucleus of the solitary tract and the importance of GABAergic neurons of this nucleus for the central cardiovascular control.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00169687

Permalink

Bibliothek	Standort	Signatur	Band/Heft/Jahr	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

5

Digitale Medien

In vivo release of newly synthesized catecholamines from the hypothalamus by amphetamine (1974)

Philippu, A. ; Glowinski, J. ; Besson, M. J.

Springer

Naunyn-Schmiedeberg's archives of pharmacology 282 (1974), S. 1-8

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1432-1912

Schlagwort(e): Hypothalamus ; Release ; Noradrenaline ; Dopamine ; Amphetamine

Quelle: Springer Online Journal Archives 1860-2000

Thema: Medizin

Notizen: Summary The posterior hypothalamus of cats immobilized with gallamine was superfused through a push-pull cannula with artificial cerebrospinal fluid. Addition of3H-tyrosine into the superfusing fluid led to synthesis of3H-catecholamines which were released spontaneously. Separation of the3H-catecholamines by column chromatography or their acetylation and separation by paper chromatography revealed that both3H-noradrenaline and3H-dopamine were released. In most experiments3H-noradrenaline represented about 10 to 25% of total3H-catecholamines. Superfusion of the hypothalamus with amphetamine (1×10−5 M) enhanced the release of total3H-catecholamines, the release of3H-noradrenaline being relatively more enhanced than that of3H-dopamine. Determination of the readioactive compounds in the hypothalamus at the end of the experiments showed that total3H-catecholamines represented 3% of3H-tyrosine. About 15% of the total3H-catecholamines were due to3H-noradrenaline and 85% to3H-dopamine.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00647398

Permalink

Bibliothek	Standort	Signatur	Band/Heft/Jahr	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

6

Digitale Medien

Changes in the arterial blood pressure increase the release of endogenous histamine in the hypothalamus of anaesthetized cats (1983)

Philippu, A. ; Hagen, R. ; Hanesch, U. ; [weitere]

Springer

Naunyn-Schmiedeberg's archives of pharmacology 323 (1983), S. 162-167

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1432-1912

Schlagwort(e): Endogenous histamine ; Release ; Arterial blood pressure ; Hypothalamus ; Cat ; Push-pull cannula

Quelle: Springer Online Journal Archives 1860-2000

Thema: Medizin

Notizen: Summary The posterior hypothalamus of anaesthetized cats was superfused with artificial CSF through a push-pull cannula and the arterial blood pressure was recorded in the femoral artery. The release of endogenous histamine was determined in the hypothalamic superfusate by a radioenzymatic assay. Intravenous injection of sodium nitroprusside elicited a fall of blood pressure which was accompanied by an increase in the rate of release of endogenous histamine in the posterior hypothalamus. Similary, a controlled bleeding lowered the arterial blood pressure and enhanced the release of histamine. The durations of depressor responses to nitroprusside or controlled bleeding coincided with the duration of the changes in the rate of release of histamine. Intravenous injection of chlorisondamine also lowered the arterial blood pressure and augmented the release of histamine. However, the hypotension lasted longer than the increased release of histamine in the hypothalamus. Intravenous injection of noradrenaline elicited a rise in the arterial blood pressure which was associated with an increase in the release of histamine in the posterior hypothalamus. Intravenous injection of tramazoline led to a long-lasting hypertension and to a short-lasting increase in the release of histamine. Transection of the spinal cord at C1/C2 elicited a pressor response which was followed by hypotension. Increase and decrease in the arterial blood pressure were associated with an increased rate of release of endogenous histamine. A second transection of the spinal cord at a higher level did not influence either blood pressure or rate of release of histamine. It is concluded that increases and decreases in the arterial blood pressure enhance the rate of release of endogenous histamine in the posterior hypothalamus of the anaesthetized cat. The alterations in the release of histamine seem to represent an immediate response of the hypothalamus to changes in peripheral blood pressure.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00634265

Permalink

Bibliothek	Standort	Signatur	Band/Heft/Jahr	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

7

Digitale Medien

Pulsatile release of catecholamines in the hypothalamus of conscious rats (1993)

Dietl, H. ; Prast, H. ; Philippu, A.

Springer

Naunyn-Schmiedeberg's archives of pharmacology 347 (1993), S. 28-33

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1432-1912

Schlagwort(e): Ultradian rhythm ; Hypothalamus ; Pushpull cannula ; Dopamine ; Noradrenaline ; Adrenaline

Quelle: Springer Online Journal Archives 1860-2000

Thema: Medizin

Notizen: Summary To investigate the patterns of catecholamine release in the brain, the hypothalamus of conscious, freely moving rats was superfused through a push-pull cannula with artificial cerebrospinal fluid and the catecholamines dopamine, noradrenaline and adrenaline were determined in the superfusate radioenzymatically. Superfusate was continuously collected in time periods of 20 min for at least 20h. Dopamine, noradrenaline and adrenaline release rates fluctuated according to an ultradian rhythm with a frequency of 1 cycle/92 min (dopamine and noradrenaline) or 99 min (adrenaline). Additionally, the three catecholamines were released according to an ultradian rhythm with the following frequencies: noradrenaline and adrenaline 1 cycle/ 12 h, dopamine 1 cycle/8 h. The release rates of dopamine and adrenaline were similar during light and dark periods, while the release rate of noradrenaline in the dark period was slightly lower than that during the light period. It is concluded that in the hypothalamus of the conscious rat the release rates of dopamine, noradrenaline and adrenaline fluctuate according to two ultradian rhythms with different frequencies.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00168768

Permalink

Bibliothek	Standort	Signatur	Band/Heft/Jahr	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

8

Digitale Medien

In vivo release of catecholamines in the locus coeruleus (1994)

Singewald, N. ; Schneider, C. ; Pfitscher, A. ; [weitere]

Springer

Naunyn-Schmiedeberg's archives of pharmacology 350 (1994), S. 339-345

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1432-1912

Schlagwort(e): Locus coeruleus ; Dopamine ; Noradrenaline ; Adrenaline ; Veratridine ; Tetrodotoxin ; Push-pull cannula ; Cat

Quelle: Springer Online Journal Archives 1860-2000

Thema: Medizin

Notizen: Abstract To investigate the release of endogenous dopamine, noradrenaline and adrenaline in the locus coeruleus, this brain area was superfused with artificial cerebrospinal fluid (CSF) through push-pull cannulae and the release of catecholamines was determined in the superfusate radioenzymatically. Collection of superfusates in time periods of 10 min revealed that release rates of the three catecholamines fluctuated, thus pointing to the existence of ultradian rhythms with following mean periods (minutes per cycle): noradrenaline 52±4, dopamine 37±2, adrenaline 36±2. The rhythm frequency of noradrenaline was significantly lower than the frequencies of dopamine and adrenaline. When the locus coeruleus was superfused with neuroactive drugs, superfusates were collected in time periods of 3 min. Superfusion with tetrodotoxin (1 μmol 1−1) for 12 min elicited a prompt and sustained decrease (−70%) in the release rates of dopamine and adrenaline. The release rate of noradrenaline was also reduced, although to a lesser extent (−40%). Superfusion with veratridine (50 μmol 1−1) led to an immediate and very pronounced enhancement in the release rates of dopamine, noradrenaline and adrenaline. The veratridine-induced increase in catecholamine outflow was decreased strongly by simultaneous superfusion with tetrodotoxin. The findings suggest that the release of endogenous catecholamines in the locus coeruleus fluctuates according to ultradian rhythms. Changes in the release on superfusion with veratridine and tetrodotoxin demonstrate the neuronal origin of the three catecholamines. The observed differences in the release characteristics between noradrenaline on the one hand and dopamine and adrenaline on the other might indicate that noradrenaline is partly released from somatodendritic sites of the noradrenergic cell bodies in the locus coeruleus.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00178948

Permalink

Bibliothek	Standort	Signatur	Band/Heft/Jahr	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

9

Digitale Medien

Uptake of serotonin, gamma-aminobutyric acid and histamine into synaptic vesicles of the pig caudate nucleus (1975)

Philippu, A. ; Matthaei, H.

Springer

Naunyn-Schmiedeberg's archives of pharmacology 287 (1975), S. 191-204

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1432-1912

Schlagwort(e): Synaptic Vesicles ; Dopamine ; GABA ; Serotonin ; Histamine ; ATP

Quelle: Springer Online Journal Archives 1860-2000

Thema: Medizin

Notizen: Summary Dopamine-containing vesicles were isolated from the caudate nucleus of the pig by differential centrifugation and incubated with 14C-serotonin (14C-5-HT), 14C-gamma-aminobutyric acid (14C-GABA), 14C-dopamine or 14C-histamine. At 25°C the uptake of 14C-5-HT and 14C-GABA was enhanced by ATP and magnesium. The Km for the uptake of 14C-5-HT in the presence of ATP and magnesium was 0.67×10−6 M, that of 14C-GABA 1.33×10−4 M. 14C-Histamine was also taken up into the vesicles but its uptake was not influenced by ATP and magnesim. The ATP-magnesium-dependent uptake of 14C-5-HT and 14C-GABA was abolished at 0°C. At 37°C the accumulation of 14C-GABA in the presence of ATP and magnesium reached a steady state after 20 min, while the accumulation of 14C-5-HT reached a maximum after 2.5 min of incubation and then gradually declined. Osmotic lysis of the vesicles followed by sonication abolished the enhanced uptake of 14C-GABA, 14C-5-HT and 14C-dopamine in the presence of ATP and magnesium. Determination of the endogenous contents of the vesicles revealed 14.6 pmoles per mg protein for 5-HT and 22.7 nmoles per mg protein for GABA. It is concluded that the caudate nucles preparation used in this study contains not only dopamine-storing vesicles able to take up biogenic amines but also GABA-containing vesicles which take up GABA by an ATP-magnesium-dependent process.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00510450

Permalink

Bibliothek	Standort	Signatur	Band/Heft/Jahr	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

10

Digitale Medien

Pattern of catecholamine release in the nucleus tractus solitarii of the cat (1989)

Lanzinger, I. ; Kobilanski, C. ; Philippu, A.

Springer

Naunyn-Schmiedeberg's archives of pharmacology 339 (1989), S. 298-301

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1432-1912

Schlagwort(e): Dopamine ; Noradrenaline ; Adrenaline ; Push-pull cannula ; Rhythmic release ; Nucleus tractus solitarii

Quelle: Springer Online Journal Archives 1860-2000

Thema: Medizin

Notizen: Summary The release of endogenous dopamine, noradrenaline and adrenaline was studied in the nucleus tractus solitarii (subnucleus medialis) of anaesthetized cats. Two push-pull cannulae were inserted into the right and left nuclei tractus solitarii which were simultaneously superfused with artificial cerebrospinal fluid. The release of the neurotransmitters was determined in the superfusates which were continuously collected in 10 min or 2.5 min time periods for 6 h or 2 h, respectively. Collection of the superfusates in time periods of 10 min showed that the release rates of endogenous dopamine, noradrenaline and adrenaline varied rhythmically according to an ultradian rhythm, the time interval between 2 adjacent phases of high release rate being approximately 1 h. Some of the phases of high release rates of the three endogenous catecholamines timely coincided with each other. Collection of the perfusates in time periods of 2.5 min revealed the existence of additional oscillations with a frequency of about 1 cycle/10 min for dopamine, noradrenaline and adrenaline. The findings suggest that catecholamines are released in the nucleus tractus solitarii according to an ultradian rhythm with low (1 cycle per h) and high (1 cycle per 10 min) frequencies, which might reflect the activity of catecholaminergic neurons in this brain structure.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00173581

Permalink

Bibliothek	Standort	Signatur	Band/Heft/Jahr	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext