Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 2

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  noradrenaline level
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
It is well known that monoamine neurotransmitters: noradrenaline (NA) and serotonin (5-HT) play a key role in central nervous system (CNS) in pathophysiology of depression. The alterations in their metabolism in the brain seem to be related to the therapeutic action of antidepressants. Abnormalities with monoaminergic storage and neurotransmission are associated with a number of neurological disorders as: e.g. depression. Reserpine, used as an antihypertensive, antipsychotic drug in a low doses is a potent inhibitor of the vesicular monoamine transporter 2 (VMAT2) and acts by depleting cells of their monoamines stores. It is known that patients who took reserpine chronically began to display symptoms similar to that seen in depression. The reserpine model of depression in rat based on universally accepted monoamine hypothesis of depression and offers good predictive validity in terms of monoamine-based antidepressant activity. The aim: the present study aimed to investigate the potential antidepressant properties of an endogenous amine 1,2,3,4-tetrahydroisoquinoline (TIQ) and its possible mechanisms of action. In behavioral study, the forced swim test (FST) was used to evaluate the effects of TIQ in reserpine model of depression in rat. Additionally, the motor function of rat was checked in locomotor activity test after investigated drugs administration. Further, the content of NA, 5-HT and their metabolites, as well as the rate of metabolism in different rat brain structures were determined by HPLC methodology with ED. The reserpine model of depression was induced by chronic (14 consecutive days) administration of reserpine in a low dose (0.2 mg/kg i.p.). Results: The results from both behavioral and neurochemical studies have shown depressive-like effect of reserpine after its chronic administration. In the behavioral tests, reserpine decreased the locomotor activity (about 30% vs. control group, P<0.05) measured in actometers (Opto-Varimex activity monitors, Columbus Instruments, USA) linked on-line to a compatible IBM-PC. 14-days administration of reserpine induced also behavioral changes in FST: increase of immobility time with a simultaneous decrease of swimming activity (about 30% vs. control group). Depressive-like action of reserpine was also observed in neurochemical study by decline NA and 5-HT levels in the brain structures, mainly in the frontal cortex and striatum. TIQ (25 mg/kg i.p.) revealed antidepressant-like effect in FST and has the ability to reverse the pro-depressive effect of reserpine. In biochemical studies, TIQ completely antagonized reserpine-induced monoaminergic depression in rat brain structures. Conclusion: The obtained data indicate first, that chronically administered reserpine at a low dose leads to a good animal model of depression. Secondly, the antidepressant-like effect of TIQ based mainly on activation of monoaminergic system and antagonizing the effect of reserpine by inhibition of MAO-dependent oxidation of monoamines and increased their concentrations in the brain. Thus, in that light TIQ may be useful as a new safer and more effective compound in clinical practice for therapy of depression.
Adrenomedullin (ADM) release is enhanced in pheochromocytoma, chronic heart failure (HF), hypertension and renal diseases. This study was designed to test the hypothesis that ADM secretion increases also in response to acute stimuli, such as static effort and to compare plasma ADM response to this stimulus in patients with chronic HF and healthy persons. Eight male HF patients (II/III class NYHA) and eight healthy subjects (C) performed two 3-min bouts of static handgrip at 30% of maximal voluntary contraction, alternately with each hand without any break between the bouts. At the end of both exercise bouts and in 5 min of the recovery period, plasma ADM and catecholamines were determined. In addition, heart rate, blood pressure, and stroke volume (SV) were measured. The baseline plasma ADM and noradrenaline levels were higher, whilst plasma adrenaline and SV were lower in HF patients than in C group. The 1st exercise bout caused an increase in plasma ADM from 3.32 ± 0.57 to 4.98 ± 0.59 pmol l-1 (p<0.01) in C and from 6.88 ± 0.58 to 7.80 ± 0.43 pmol·l-1 (p<0.02) in HF patients. The 2nd exercise bout did not produce further elevation in plasma ADM and during recovery the hormone concentration declined to pre-exercise or lower values. There were no differences between groups in exercise-induced increases in plasma ADM. Plasma ADM correlated with SV (r = -0.419) and with noradrenaline concentrations (r = 0.427). It is concluded that static exercise causes the short-lasting increase in plasma ADM concentration which is similar in healthy subjects and in patients with mild heart failure.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.