[Psychopharmacological properties of crude extract and essential oil of Lippia multiflora]. / Propriétés psychopharmacologiques de l'extrait brut et de l'huile essentielle de Lippia multiflora.

Psychopharmacological properties of crude extract and essential oil of Lippia multiflora (Lm), a verbenacea of african traditional pharmacopea were investigated in rat using classical methods. The extract of Lm is constituted by an infusion of dried leaves. The essential oil is obtained by hydrodistillation of the dried leaves of Lm with a yield of 0.6%. A dilution of 1% is realised with distilled water and the dose of 2 ml/kg of this solution was chosen for this study. The wistar rats of both sexes weighting between 150 and 250 g are used. Animal's behaviour is observed macroscopically for 12 hours. The spontaneous motor activity is appreciated by method of Martin et al. slightly modified. The number of squares jumped by animals in a rectangular cage is determined in ten minutes. The traction test which measures the time necessary for restoration of posterior paws of rat on metallic bar and the duration of pentobarbital sleeping are used for evaluation of muscle relaxant and sedative effects, respectively. The effects of the two preparations of Lm on apomorphin stereotypies and hypothermia are used to investigate the eventual neuroleptic or antidepressant activity. Analgesic property is evaluated by using acetic acid method. The results are expressed as mean +/- SEM. Data are analysed by using the Dunnett's test. A probability level of 0.05 or less was considered to be stalistically significant. The two preparations of Lm at the doses used are well tolerated by rats. No macroscopic difference is observed in behavioural of control and treated groups. Crude extract and essential oil:--does not modify a spontaneous motor activity: control: 45.00 +/- 5.63; crude extract of Lm: 31.00 +/- 5.63; essential oil of Lm: 28.00 +/- 7.62; diazepam 4 mg/kg: 23.80 +/- 5.27 (P < 0.05);--caused an increase of the time necessary for the restoration of paws on the metallic bar in the traction test: control 1.20 +/- 0.25 sec; crude extract of Lm 5.60 +/- 0.57 sec (P < 0.01), essential oil of Lm. 3.60 +/- 0.57 sec (P < 0.01) diazepam 3.60 +/- 0.57 sec (P < 0.01). The differences between the results obtained with crude extract, essential oil and diazepam are significant;--caused a reduction of abdominal cramps induced by acetic acid, control: 26.80 +/- 0.41; crude extract of Lm: 17.00 +/- 1.45 (P < 0.01); essential oil of Lm: 9.20 +/- 1.91 (P < 0.01) and acetylsalicylic acid (Aspegic*) 25 mg/kg 5.40 +/- 1.25 (P < 0.01). The differences is significant between essential oil and crude extract (P < 0.05) but no significant difference is observed between essential oil and acetylsalicylate of lysin. No activity of the two preparations is observed on apomorphin stereotypia and hypothermia comparatively with haloperidol 4 mg/kg and clomipramin 16 mg/kg respectively. Those results confirm the tranquillizer and analgesic activities of Lm and reveal that the crude extract would be more muscle relaxant and the essential oil more analgesic.

Transmural microcirculatory blood flow distribution in right and left ventricular free walls of rabbits.

Within-layer regional myocardial flows in the left and right ventricles (LV, RV) and in LV with increased myocardial workload (beta(1)-adrenoceptor stimulation) were studied transmurally in anesthetized rabbits. Myocardial flow distribution was visualized with resolutions between 0.1 x 0.1- and 1 x 1-mm(2) pixels, using digital radiography combined with the (3)H-labeled desmethylimipramine deposition technique. The spatial pattern of flow distribution was quantitated by the coefficient of variation of regional flows (CV, related to global flow heterogeneity) and the correlation between adjacent regional flows (CA, inversely related to local flow randomness). CV was lower in LV than in RV [P < 0.05, nonparametric 2-way analysis of variance (NANOVA)]. When resolution was lowered from 0.1 x 0.1- to 1 x 1-mm(2) pixels, CV decreased by 70% in both LV and RV. CA was higher in LV than in RV (P < 0.05, NANOVA); the interventricular difference in CA was large over the resolutions between 0.4 x 0.4- and 1 x 1-mm(2) pixels. In LV, both CV and CA increased with depth of myocardium (P < 0.05, NANOVA); in subendocardium CV was high comparable with CV in RV (P = 0.47, NANOVA). The enhancement of myocardial workload decreased CV and tended to decrease CA in LV subendocardium (P < 0.05, P = 0.06, respectively; NANOVA). We conclude that 1) microregional flow distribution is less heterogeneous and less random in LV than in RV; 2) transmurally, in LV subendocardium global flow heterogeneity was the highest whereas local flow randomness was the lowest, so that clusters of low- or high-flow regions exist in this LV layer; and 3) global flow heterogeneity decreased and local flow randomness tended to increase (flow homogenizing occurred) in LV subendocardium with increasing myocardial workload. Thus the distributed pattern of myocardial microregional flows may be adaptable to local myocardial metabolic change.

Endothelium-derived nitric oxide enhances the effect of intraaortic balloon pumping on diastolic coronary flow.

BACKGROUND: High shear rate with pulsation is one of the major stimuli for the release of endothelium-derived nitric oxide leading to coronary arteriolar dilation. Intraaortic balloon pumping mechanically enhances shear rate and diastolic-to-systolic flow oscillation. We aimed to evaluate whether or not coronary blood flow augmentation during intraaortic balloon pumping is mediated by coronary arteriolar dilation through endothelium-derived nitric oxide release. METHODS: Using a charge-coupled device intravital videomicroscope, we observed epicardial coronary arterioles (40 to 220 microm in diameter) in anesthetized open-chest dogs (n = 10) during 2:1 mode of intraaortic balloon pumping. Endothelium-derived nitric oxide-mediated vasodilatory effects of intraaortic balloon pumping were evaluated by comparing end-diastolic arteriolar diameters between the coupled beats of on and off intraaortic balloon pumping before and after intracoronary endothelium-derived nitric oxide synthesis inhibition with Nomega-nitro-L-arginine (L-NNA, 2 micromol/min) administration. RESULTS: Intraaortic balloon pumping increased coronary arteriolar diameters and coronary blood flow by 11.4%+/-1.8% (p < 0.0001) and 33.4%+/-4.1% (p < 0.001), respectively. Vasodilation was greater in small arterioles (<110 microm; 15.4%+/-2.2%) than in large arterioles (> or =110 microm; 4.2%+/-1.2%, p < 0.0001). L-NNA attenuated the intraaortic balloon pumping-induced vasodilation and augmentation of coronary blood flow to 4.6%+/-1.0% (p < 0.001) and to 20.8%+/-2.1%, (p < 0.05), respectively. Attenuation of vasodilatory effect by L-NNA was observed mainly in small arterioles (from 15.4%+/-2.2% to 5.9%+/-1.2%). CONCLUSIONS: Intraaortic balloon pumping augmented coronary blood flow by dilating coronary arterioles in diastole, more significantly in small arterioles than in large arterioles. Endothelium-derived nitric oxide inhibition markedly attenuated these effects. We conclude that, in a canine model, endothelium-derived nitric oxide contributes to mechanical enhancement of the coronary blood flow with diastolic arteriolar vasodilation during intraaortic balloon pumping.

Spatial fluctuation of regional myocardial blood flows.

Digital radiography (100 pixels/mm2) combined with the technique of 3H-labeled desmethylimipramine deposition was employed to visualize regional blood flow distributions in rabbit left ventricular myocardium. A fluctuated pattern of myocardial flow and its dependence on arterial oxygen tension (PaO2) was evaluated with the coefficient of variation (CV) computed at each step of coarse-graining; flow images were revisualized by increasing pixel area (PA) step by step from 0.01 to 1 mm2. The CV values decreased with hypoxia at all resolution levels, suggesting that there is a vascular regulatory mechanism for making myocardial perfusion uniform in response to decreased PaO2. In both perfusion states, CV decreased with increasing PA. The relationship between CV and PA fitted the noninteger power law function, implying an apparent fractality of CV.

Effects of intraaortic balloon pumping on septal arterial blood flow velocity waveform during severe left main coronary artery stenosis.

OBJECTIVES: We sought to evaluate the effect of intraaortic balloon pumping on the phasic blood velocity waveform into myocardium with severe coronary artery stenosis. BACKGROUND: In the presence of severe coronary artery stenosis, it is not clear whether intraaortic balloon pumping augments intramyocardial inflow during diastole or changes systolic retrograde blood flow from the myocardium to the extramural coronary arteries. METHODS: Using anesthetized open chest dogs (n=7), we introduced severe stenosis in the left main coronary artery to reduce the poststenotic pressure to approximately 60 mm Hg (>90% diameter stenosis). Septal arterial blood flow velocities were measured with a 20-MHz, 80-channel ultrasound pulsed Doppler velocimeter. Left anterior descending arterial flow, aortic pressure and poststenotic distal coronary pressure were measured simultaneously. The diastolic anterograde flow integral and systolic retrograde flow integral were compared in the presence and absence of intraaortic balloon pumping. RESULTS: Although intraaortic balloon pumping augmented diastolic aortic pressure, this pressure increase was not effectively transmitted through stenosis. Septal arterial diastolic flow velocity was not augmented, and left anterior descending arterial flow was unchanged during intraaortic balloon pumping. CONCLUSIONS: In the presence of severe coronary artery stenosis, intraaortic balloon pumping failed to increase diastolic inflow in the myocardium and did not enhance systolic retrograde flow from the myocardium to the extramural coronary artery. Thus, the major effect of intraaortic balloon pumping on the ischemic heart with severe coronary artery stenosis may be achieved by reducing oxygen demand by systolic unloading.

[Autonomic function and severity of hypertrophic cardiomyopathy by power spectrum analysis on heart rate variability].

To examine the relation of autonomic function and severity of hypertrophic cardiomyopathy (HCM) with and without ventricular tachycardia (VT) and poor blood pressure response on Treadmill exercise, 30 patients with HCM and 10 healthy controls were selected. Autonomic function was assessed by heart rate variability (HRV) on 24hr-Holter monitoring. The power spectrum analysis was classified into LF component, HF component and ratio of LF/HF. (1) Night time HF and LF decreased, and LF/HF increased in HCM compared with healthy controls. (2) HF decreased more in HCM with VT. (3) LF/HF also decreased in HCM with poor blood pressure response on exercise. These results suggest that autonomic function may be altered in HCM, and severity of HCM proved to be able to be assessed by power spectrum analysis of HRV.