The crucial role of the immune system in hypertension is now widely recognized. We previously reported that hypertensive challenges couple the nervous drive with immune system activation, but the physiological and molecular mechanisms of this connection are unknown. Here, we show that hypertensive challenges activate splenic sympathetic nerve discharge to prime immune response. More specifically, a vagus-splenic nerve drive, mediated by nicotinic cholinergic receptors, links the brain and spleen. The sympathetic discharge induced by hypertensive stimuli was absent in both coeliac vagotomized mice and in mice lacking α7nAChR, a receptor typically expressed by peripheral ganglionic neurons. This cholinergic-sympathetic pathway is necessary for T cell activation and egression on hypertensive challenges. In addition, we show that selectively thermoablating the splenic nerve prevents T cell egression and protects against hypertension. This novel experimental procedure for selective splenic denervation suggests new clinical strategies for resistant hypertension.
In recent decades, as a result of rising mortality rates due to cardiovascular diseases (CVDs), there has been a growing urgency to find alternative approaches to conventional pharmaceutical treatment to prevent the onset of chronic diseases. Arthrospira platensis, commonly known as Spirulina, is a blue-green cyanobacterium, classified as a “superfood”, used worldwide as a nutraceutical food supplement due to its remarkable nutritional value, lack of toxicity, and therapeutic effects. Several scientific studies have evaluated the cardioprotective role of Spirulina. This article presents a comprehensive review of the therapeutic benefits of Spirulina in improving cardio- and cerebrovascular health. It focuses on the latest experimental and clinical findings to evaluate its antihypertensive, antidiabetic, and antihyperlipidemic properties. The objective is to highlight its potential in preventing and managing risk factors associated with cardiovascular disease (CVD).
Omega-3 fatty acids have been shown to exert several beneficial effects in the prevention of cardiovascular and cerebrovascular diseases. The objective of the present study was to analyze the effects of a novel high-load omega-3 lysine complex, AvailOm®, its related constituents and a novel mixture of AvailOm® with specific vasoactive anthocyanins on vascular function in mice resistance artery. Pressure myograph was used to perform vascular reactivity studies. Nitric oxide and oxidative stress were assessed by difluorofluorescein diacetate and dihydroethidium, respectively. Increasing doses of AvailOm® exerted a dose-response vasorelaxation via AMPK-eNOS-mediated signaling. Omega-3 Ethyl Ester was identified as the main bioactive derivative of AvailOm®, being capable of inducing vasorelaxant action to the same extent of entire product. The combination of AvailOm® with a mix of potent vasoactive anthocyanins (C3-glu + DP3-glu + Mal3-glu + Mal3-gal + PEO3-gal), strongly protected mesenteric arteries from vascular dysfunction and oxidative stress evoked by oxidized-LDL. These data demonstrate for the first time the direct effects of AvailOm® on resistance arteries. The evidence that the combination of specific vasoactive anthocyanins and AvailOm® further enhanced the vasculoprotective properties of these compounds, may offer new promising perspectives for preventing the onset of cardiovascular and cerebrovascular events.
Methamphetamine (METH) exposure increases locomotor sensitization. However, no study has explored the occurrence of cardiovascular sensitization. The present study, carried out in mice, analyzed the following: (i) METH sensitization extending to systolic blood pressure (SBP); (ii) a potential correlation between ambulatory and cardiovascular sensitization; and (iii) morphological alterations within meso-striatal, meso-limbic and pontine catecholamine systems including c-fos expression. Locomotor activity, SBP and occurrence of morphological alterations of catecholaminergic neurons were assessed in C57Bl/6J mice following daily i.p. injections of either saline or METH (1, 2 or 5 mg/kg) for 5 consecutive days and following 6 days of withdrawal. Reiterated exposure to the lower doses of METH (1 mg/kg and 2 mg/kg) produced in mice locomotor sensitization without altering SBP. In contrast, repeated treatment with the highest dose of METH (5 mg/kg) produced sensitization of SBP in the absence of locomotor sensitization. No morphological alterations but increases in c-fos expression within neurons of locus coeruleus and nucleus accumbens were detected. The present data suggest that METH produces plastic changes that extend beyond the motor systems to alter autonomic regulation. This cardiovascular sensitization occurs independently of locomotor sensitization. The persistency of increased blood pressure may underlie specific mechanisms operating in producing hypertension.
Methamphetamine (METH) is a drug of abuse, which induces behavioral sensitization following repeated doses. Since METH alters blood pressure, in the present study we assessed whether systolic and diastolic blood pressure (SBP and DBP, respectively) are sensitized as well. In this context, we investigated whether alterations develop within A1/C1 neurons in the vasomotor center. C57Bl/6J male mice were administered METH (5 mg/kg, daily for 5 consecutive days). Blood pressure was measured by tail-cuff plethysmography. We found a sensitized response both to SBP and DBP, along with a significant decrease of catecholamine neurons within A1/C1 (both in the rostral and caudal ventrolateral medulla), while no changes were detected in glutamic acid decarboxylase. The decrease of catecholamine neurons was neither associated with the appearance of degeneration-related marker Fluoro-Jade B nor with altered expression of α-synuclein. Rather, it was associated with reduced free radicals and phospho-cJun and increased heat shock protein-70 and p62/sequestosome within A1/C1 cells. Blood pressure sensitization was not associated with altered arterial reactivity. These data indicate that reiterated METH administration may increase blood pressure persistently and may predispose to an increased cardiovascular response to METH. These data may be relevant to explain cardiovascular events following METH administration and stressful conditions.