The application of dopamine agonists in Parkinson’s disease has been a hot topic in recent years. Can dopamine receptor agonists serve as the initial drugs for Parkinson’s disease? Does it improve the natural history of patients? Has it neuroprotective role? When and how to use dopamine receptor agonists? This article provides evidence on the pros and cons of dopamine receptor agonists in the treatment of Parkinson’s disease for helping clinical decision making.
Abstract： Objective To use tissue Doppler strain rate imaging to evaluate the impact of low dose dopamine and milrinone on systolic and diastolic function of the left ventricle of patients undergoing heart valve replacement. Methods Forty patients undergoing selective heart valve replacement in West China Hospital of Sichuan University between March and May 2011 were included in this study. All the patients were randomized into 2 groups with 20 patients in each group： milrione group and dopamine group. After anesthesia induction and before cardiopulmonary bypass setup， left ventricular ejection fraction （LVEF） was measured by echocardiography. Tissue Doppler strain rate imaging was used to measure the left ventricular lateral wall and midventricular segment from the four-chamber view， which was compared with Doppler parameters. Results LVEF， ratio of early-diastolic to end-diastolic velocity （E/A） of transmitral flow， ratio of mitral inflow velocity to early diastolic velocity in the annulus （E/Et） of both 2 groups were significantly different between before and after dopamine and milrinone administration （P＜0. 05）. In the milrinone group， 4 segments systolic peak velocity （Vs）， 1 segment early diastolic peak velocity （Ve）， 4 segments late diastolic peak velocity （Va）， 3 segments Ve/Va ratio， 2 segments systolic peak strain rate （SRs）， 2 segments late diastolic peak strain rate （SRa）， and 3 segments early diastolic peak strain rate SRe/SRa ratio after dopamine and milrinone administration were significantly higher than those before dopamine and milrinone administration （P＜0. 05）. In the dopamine group， 4 segments systolic peak velocity （Vs）， 1 segment Ve， 4 segments Va， 1 segment Ve/Va ratio， 2 segments SRs， 1 segment SRe， 1 segment SRa， and 1 segment SRe/SRa ratio after dopamine and milrinone administration were significantly higher than those before dopamine and milrinone administration （P＜0.05）. To compare the milrione group and dopamine group after medication administration， 2 segments Vs， 4 segments Va， 1 segment SRe， 1 segment SRa， 2 segments Ve/Va ratio， and 2 segments SRe/SRa ratio of the milrione group were significantly higher than those of the dopamine group （P＜0.05）， and 1 segment Vs， two segments SRs of the milrione group were significantly lower than those of the dopamine group （P＜0.05）. Conclusion Both milrinone and dopamine can improve left ventricular systolic function of perioperative patients undergoing heart valve replacement assessed by tissue Doppler strain rate imaging， while milrinone can improve the diastolic function of the left ventricle on the long axis more significantly.
Objective To compare the vasoactive effects of norepinephrine( NE) and dopamine of different doses on isolated rabbit pulmonary and systemic arteries in septic shock. Methods Six paired pulmonary and systemic arterial rings were prepared fromsix rabbits, and matched randomly assigned into a normal group and a LPS group. The assigned groups were intervened by different doses of NE. Another six paired pulmonary and systemic arterial rings were prepared from another six rabbits. They were assigned to different groups as above and intervened by different doses of dopamine. The LPS groups were pre-incubated in RPMI mediumsupplemented with4 μg/mL LPS to simulate septic shock. The tension of arterial rings was measured and its response to NE and dopamine were studied. Results ( 1) In the normal groups, the contraction of the systemic arteries was ber than the pulmonary arteries in response to low,middle dose of NE, and high dose of dopamine ( all P lt; 0. 05) , and which was weaker in response to middle dose of dopamine and similar in response to high dose of NE( P gt;0. 05) . Both the pulmonary and systemic arteriesrelaxed in response to low dose of dopamine. ( 2) After LPS pre-incubation, the contraction of the systemic arteries was weaker than the pulmonary arteries in response to low dose of dopamine ( P lt;0. 05) , and which was similar in response to low,middle and high dose of NE, and middle, high dose of dopamine. ( 3) Comparing the LPS groups with the normal groups, the contraction in response to middle dose of dopamine increased in the systemic arteries and dreased in the pulmonary arteries ( P lt;0. 05) . Conclusions In septic shock, the vasoactive effect of different doses of NE is not different between pulmonary and systemic arteries. But middle dose of dopamine can increase the contraction of systemic arteries and decrease the contraction of pulmonary arteries.
1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline (Sal) is a kind of catechol isoquinoline compound, which mainly exists in mammalian brain and performs a variety of biological functions. Through in vivo metabolism, Sal can be transformed into endogenous neurotoxins and can participate the occurrence of Parkinson’s disease (PD). This has attracted widespread concern of researchers. Recently, many research works have shown that Sal may lead to alcohol addiction and regulate hormone release of the neuroendocrine system, which indicated that it is a potential regulator of dopaminergic neurons. In this paper, we discuss the neural functions of Sal on the above aspects, and wish to provide some theoretical supports for further research on its mechanism.
Objective To systemically review the efficacy and safety of dopamine versus norepinephrine in patients with septic shock. Methods Database searches of MEDLINE, EMbase, Cochrane Controlled Trials Register, VIP, CNKI, and CBM (from the date of database establishment to June 2011) were conducted. Additional studies for collecting relevant data were retrieved via both references of articles and direct contact with authors. Prospectively, randomized controlled trials (RCTs) of dopamine compared with norepinephrine therapy in septic shock patients were selected. The quality of included trials was assessed and relevant data were extracted. Then statistical analysis was performed using RevMan 5.1. Results Nine trials with 3 179 participants were included. The results of meta-analysis showed: compared with norepinephrine, dopamine was associated with a significant 12% elevation in the risk ratio of in-hospital death events of septic shock patients (RR=1.12, 95%CI 1.04 to 1.21, P=0.002). The risk of arrhythmias in dopamine group was 2.63-fold than that in norepinephrine group (RR=2.63, 95%CI 1.51 to 4.55, P=0.000 6). The cardiac index of septic patients in dopamine group was higher than that in norepinephrine group (MD=0.42, 95%CI 0.21 to 0.63, Plt;0.000 1). No significant difference could be found in the heart rate (MD=17.05, 95%CI –0.71 to 34.81, P=0.06) and mean arterial pressure (MD= –0.87, 95%CI –24.97 to 7.62, P=0.30). Conclusion Findings from this meta-analysis suggest that compared with dopamine, norepinephrine significantly reduces both 28-day mortality of septic shock patients and incidence rate of arrhythmias. Norepinephrine is better than dopamine in aspects of efficacy and safety.
ObjectiveTo study the effect of rotenone on rat substantia nigra dopamine (DA) in the nervous system and oxidative stress parameters (malondialdehyde and glutathione), the influence of rotenone on DA neurons toxic effect and its pathogenesis.
MethodsThis study applied back subcutaneous injection of rotenone in rats [1.0 mg/(kg·d)], and used immunocytochemistry technique to detect changes in the expression of tyrosine kinase (TH) in 10 rats of the control group and 10 rats of the experimental group. Spectrophotometry was used to detect the change of oxidative stress parameters in rats (malondialdehyde and glutathione).
ResultsDA neurons in rats had various degrees of damage. The TH immune response strength of rats in the substantia nigra and striatum decreased significantly. The number of immune response nigra TH positive neurons was significantly less in the experimental group than in the control group (P< 0.01). Spectrophotometer method was used to detect the midbrain nigra of glutathione, which was significantly less in the experimental group than in the control group (P<0.01). Malondialdehyde in the experimental group was significantly higher (P<0.01).
ConclusionRotenone has obvious neurotoxicity, and can lead to the damage of DA neurons and obvious oxidative stress injury in rats, which provides an experimental basis for the pathogenesis of Parkinson's disease, and at the same time provides new targets for the treatment.
