High Blood Pressure Induced by Audiovisual Stimulation in Young Rats: Effect of Antihypertensive Agents

A, Florentino; Castro, Antonio de; Ja, Fuentes

doi:10.1080/07300077.1988.11878791

Cited by 5 publications

(4 citation statements)

References 10 publications

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“…Indeed, the authors reported that suppression of the pituitary adrenocorticotropic hormone (ACTH) response to stress blocked the interference following OFL presentation, suggesting that this interference was partly due to the release of ACTH (Netto et al 1991). Stimulation with flashing lights is typically used within chronic stress paradigms (Gamaro et al 2003;Grippo et al 2003), and has been shown to induce high blood pressure when paired with an intense sound (Florentino et al 1988). As previously said, the events we used to modulate spatial memory did not include aversive stimuli.…”

Section: Behavioral Interpretationmentioning

confidence: 86%

The role of rewarding and novel events in facilitating memory persistence in a separate spatial memory task

2014

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Many insignificant events in our daily life are forgotten quickly but can be remembered for longer when other memorymodulating events occur before or after them. This phenomenon has been investigated in animal models in a protocol in which weak memories persist longer if exploration in a novel context is introduced around the time of memory encoding. This study aims to understand whether other types of rewarding or novel tasks, such as rewarded learning in a T-maze and novel object recognition, can also be effective memory-modulating events. Rats were trained in a delayed matching-to-place task to encode and retrieve food locations in an event arena. Weak encoding with only one food pellet at the sample location induced memory encoding but forgetting over 24 h. When this same weak encoding was followed by a rewarded task in a T-maze, the memory persisted for 24 h. Moreover, the same persistence of memory over 24 h could be achieved by exploration in a novel box or by a rewarded T-maze task after a "non-rewarded" weak encoding. When the one-pellet weak encoding was followed by novel object exploration, the memory did not persist at 24 h. Together, the results confirm that place encoding is possible without explicit reward, and that rewarded learning in a separate task lacking novelty can be an effective memory-modulating event. The behavioral and neurobiological implications are discussed.

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Section: Behavioral Interpretationmentioning

confidence: 86%

The role of rewarding and novel events in facilitating memory persistence in a separate spatial memory task

2014

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“…Cicletanine was also tested in rats made hypertensive by isolation or by audiovisual stimulation. The drug was effective at single oral doses of 10 and 30 mg/ kg ( 10 ).…”

Section: P E Chabrier Et Almentioning

confidence: 98%

“…- 10 i, 10 20 lar reactivity to vasoconstrictor substances, demonstrable even in the prehypertensive state. The effects of 2 weeks of oral treatment with cicletanine (0.3-300 mg/ kg) on the onset of hypertension in SH-SP rats on high salt diets were compared with those of four other antihypertensive drugs: prazosin, an a-blocker (3-30 mg/kg), captopril, an inhibitor of angiotensin-converting enzyme (0.3-300 mg/kg), indapamide (0.1-0.3 mgkg), and hydrochlorothiazide (1-10 mg/kg), diuretics (22).…”

Section: P E Chabrier Et Almentioning

confidence: 99%

Cicletanine

Chabrier

Guinot

Tarrade

et al. 1988

Cardiovascular Drug Reviews

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Cicletanine hydrochloride is a new antihypertensive molecule synthetized and studied in our laboratory. Its chemical structure is uncommon for an antihypertensive molecule; it is characterized by the presence of a furopyridine group. Cicletanine is, therefore, a member of a new family of compounds with primarily antihypertensive properties, although some of the furopyridine derivatives have also antiallergic and antiinflammatory effects.The mechanism by which cicletanine lowers blood pressure has not been definitively established, although it appears to differ from that of other classes of antihypertensive drugs. Cicletanine acts on vascular smooth muscle by increasing prostacyclin synthesis and by interacting either directly with cytosolic Ca2+ pools or indirectly through various agents capable of mobilizing intracellular Ca ' ' , e.g., histamine.Studies in animals and humans demonstrated that the antihypertensive effect of cicletanine is clearly dissociable from its renal effect, which can be seen only at highdose levels of the drug.Clinical trials have confirmed the efficacy and safety of cicletanine in the treatment of hypertension, both as monotherapy or in combination with other antihypertensive drugs. CHEMISTRYCicletanine was synthetized by Esanu et al. (9) in the research laboratories of Institute Henri Beaufour, Le Plessis-Robinson (France). It was selected from a large number of furopyridines for its specific antihypertensive activity and very low, if any, toxicity. The chemical structure of cicletanine ( HCl) : (-+ ) 3-(4-chloropheny1)-1,3dihydro-7-hydroxy-6-methyl furo[3,Cc]pyridine is shown in Fig. 1. Its chemical synthesis from 2-,2,8-trimethyl-5-formyl pyrido [ 4,3-el 1,3-dioxine has been described (9). Cicletanine HC1 has a molecular weight of 298.2. It is not soluble in 166 CICLE TANINE 167 water, but soluble in ethanol and dimethyl sulfoxide. It is a white crystalline powder with a melting point of 2 19-228°C. PHARMACOLOGY Effect on Blood PressureThe activity of cicletanine on blood pressure was evaluated in anesthetized normotensive rats and dogs and in several models of hypertensive rats: desoxycorticosterone acetate, spontaneously ( SH ) and stroke-prone spontaneously ( SH-SP) hypertensive rats and rats with stress-induced hypertension.In the anesthetized normotensive rat, cicletanine, administered orally at 100 and 300 mg/kg, did not affect either mean blood pressure or heart rate. The blood pressure effects of epinephrine, norepinephrine, acetylcholine, isoproterenol, or serotonin were not altered by pretreatment with cicletanine.The effect of intravenously injected cicletanine on the main hemodynamic cardiovascular parameters-systolic and diastolic aortic pressure, heart rate, aortic blood flow, coronary (circumflex artery) and femoral arterial blood flow-were studied in anesthetized normotensive dog. At doses higher than 5 mg/kg i.v., cicletanine produced only a slight and transient bradycardia, a minor reduction of systolic arterial pressure, and a brief decrease in diastolic pressure. F...

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“…For example, in one study mice were exposed to sound for 24 h (Yu et al, 2005), in another study rats were maintained in visually stimulating environment for 8 h (Bissig and Berkowitz, 2009). Such long periods of passive (and unavoidable) exposure to sensory stimulation may produce nonphysiological patterns of activations reflecting not only the prolonged stimulation but also stress responses (Florentino et al, 1988;Geber, 1966;Hartel and Hartel, 1960). In the present study, we tested rat voluntary behavior; the amount of running activity was not restricted by the experimenter, which makes, in our opinion, this experimental situation physiologically more natural.…”

Section: Application Of Memri For Whole-brain Mapping In Behaving Animentioning

confidence: 99%

Mapping of functional brain activity in freely behaving rats during voluntary running using manganese-enhanced MRI: Implication for longitudinal studies

et al. 2010

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Magnetic resonance imaging (MRI) is widely used in basic and clinical research to map the structural and functional organization of the brain. An important need of MR research is for contrast agents that improve soft-tissue contrast, enable visualization of neuronal tracks, and enhance the capacity of MRI to provide functional information at different temporal scales. Unchelated manganese can be such an agent, and manganese-enhanced MRI (MEMRI) can potentially be an excellent technique for localization of brain activity (for review see Silva et al., 2004). Yet, the toxicity of manganese presents a major limitation for employing MEMRI in behavioral paradigms. We have tested systematically the voluntary wheel running behavior of rats after systemic application of MnCl 2 in a dose range of 16-80 mg/kg, which is commonly used in MEMRI studies. The results show a robust dose-dependent decrease in motor performance, which was accompanied by weight loss and decrease in food intake. The adverse effects lasted for up to 7 postinjection days. The lowest dose of MnCl 2 (16 mg/kg) produced minimal adverse effects, but was not sufficient for functional mapping. We have therefore evaluated an alternative method of manganese delivery via osmotic pumps, which provide a continuous and slow release of manganese. In contrast to a single systemic injection, the pump method did not produce any adverse locomotor effects, while achieving a cumulative concentration of manganese (80 mg/kg) sufficient for functional mapping. Thus, MEMRI with such an optimized manganese delivery that avoids toxic effects can be safely applied for longitudinal studies in behaving animals.

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High Blood Pressure Induced by Audiovisual Stimulation in Young Rats: Effect of Antihypertensive Agents

Cited by 5 publications

References 10 publications

The role of rewarding and novel events in facilitating memory persistence in a separate spatial memory task

The role of rewarding and novel events in facilitating memory persistence in a separate spatial memory task

Cicletanine

Mapping of functional brain activity in freely behaving rats during voluntary running using manganese-enhanced MRI: Implication for longitudinal studies

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