The alpha antagonist tamsulosin impairs memory acquisition, consolidation and retrieval in a novel object recognition task in mice.

Tamsulosin is an α-adrenoceptor antagonist used to treat benign prostatic hyperplasia. This drug exhibits high affinity for α- and α-adrenoceptor subtypes, which are also expressed in the brain. While dementia symptoms have been reported after administration of tamsulosin in humans, studies on its effects on the rodent brain are still rare.

Activation of NOP receptor increases vulnerability to stress: role of glucocorticoids and CRF signaling.

Rationale: Recently, we demonstrated that the activation of the nociceptin/orphanin FQ (N/OFQ) receptor (NOP) signaling facilitates depressive-like behaviors. Additionally, literature findings support the ability of the N/OFQ-NOP system to modulate the hypothalamic-pituitary-adrenal (HPA) axis.

Objectives: Considering that dysfunctional HPA axis is strictly related to stress-induced psychopathologies, we aimed to study the role of the HPA axis in the pro-depressant effects of NOP agonists.

Smooth muscle contraction of the fundus of stomach, duodenum and bladder from mice exposed to a stress-based model of depression.

Several reports have demonstrated that depressive disorder is related to somatic symptoms including gastrointestinal or genitourinary alterations. The pathophysiological mechanisms underlying the gastrointestinal or genitourinary alterations associated with the depression are still not fully understood. Therefore, this study aimed to evaluate the motor activity of gastrointestinal (fundus of stomach and duodenum) and genitourinary tract (bladder) in a stress-based animal model of depression.

Effects of histamine on the contractility of the rat distal cauda epididymis.

The motor activity of the epididymis duct is an essential process for male fertility and it is regulated by hormonal, neuronal and epithelial mechanisms. However, although there is evidence for the presence of histamine in the epididymis, its effects on epididymal motor activity are unknown. This study sought to evaluate the contractile effects of histamine on the rat distal cauda epididymis duct.

Tamsulosin facilitates depressive-like behaviors in mice: Involvement of endogenous glucocorticoids.

The benign prostatic hyperplasia (BPH) is the main source of lower urinary tract symptoms. The BPH is a common age-dependent disease and tamsulosin is an α-adrenoceptor blocker widely prescribed for BPH. Beyond the common adverse effects of tamsulosin, increased diagnosis of dementia after prescription was observed.

Effects of dipyrone and acetylsalicylic acid on contractions of distal cauda epididymis duct, serum testosterone and sperm count in rats.

The effects of dipyrone and acetylsalicylic acid (ASA) on male fertility are still not fully understood, mainly considering the epididymis as a putative target for their anti-fertility effects. Therefore, this study aimed to investigate the effects of dipyrone and ASA on the contractions of distal cauda epididymis duct, serum testosterone levels and sperm parameters in rats. Firstly, we checked the in vitro effects of dipyrone and ASA (10-1000 μM) on the contractions of distal cauda epididymis duct by pharmacological experiments.

Blockade of nociceptin/orphanin FQ signaling facilitates an active copying strategy due to acute and repeated stressful stimuli in mice.

The role of stress in the etiology of depression has been largely reported. In this line, exogenous glucocorticoids are employed to mimic the influence of stress on the development of depression. The N/OFQ-NOP receptor system has been implicated in the modulation of stress and emotional behaviors.

Physiopharmacological properties of the testicular capsule: A concise review.

The testicular capsules of different mammalian species exhibit spontaneous motor activity. In addition, contractions can be mediated by neuronal stimulation or exogenous drug administration. However, the physiological role of testicular capsule motor activity is still not well understood.

Intrinsic Adaptation of SHR Right Atrium Reduces Heart Rate.

Hypertension represents an autonomic dysfunction, characterized by increased sympathetic and decreased parasympathetic cardiovascular tone leading to resting tachycardia. Therefore, studies assessing hypertension-associated changes in isolated cardiac tissues were conducted under electric field stimulation to stimulate the neurons. Herein, we characterize the influence of the autonomic neurotransmitter on the baseline atrial chronotropism of unpaced isolated right atria of normotensive Wistar rats (NWR) and spontaneously hypertensive rats (SHR).

Dopamine D and D receptors mediate neuropeptide S-induced antinociception in the mouse formalin test.

Neuropeptide S (NPS) is the endogenous ligand of a G-protein coupled receptor named NPS receptor. The NPS system controls several biological functions, including anxiety, wakefulness, locomotor activity, food intake, and pain transmission. A growing body of evidence supports facilitatory effects for NPS over dopaminergic neurotransmission.

What makes the α -adrenoceptor gene product assume an α -adrenoceptor phenotype?

The α -adrenoceptor is abundantly expressed in the lower urinary tract and is the principal therapeutic target for the symptomatic treatment of lower urinary tract symptoms in men. Prazosin has a lower affinity for the lower urinary tract α -adrenoceptor than α -adrenoceptors found in other parts of the body. This has led to the lower urinary tract α -adrenoceptor being subclassified as an α -adrenoceptor.

Mirabegron: potential off target effects and uses beyond the bladder.

Unlabelled: The β -adrenoceptor was initially an attractive target for several pharmaceutical companies due to its high expression in rodent adipose tissue, where its activation resulted in decreased adiposity and improved metabolic outputs (such as glucose handling) in animal models of obesity and Type 2 diabetes. However, several drugs acting at the β -adrenoceptor failed in clinical trials. This was thought to be due to their lack of efficacy at the human receptor.

Cardiac arrest induced by muscarinic or adenosine receptors agonists is reversed by DPCPX through double mechanism.

In the right atrium (RA), adenosine and acetylcholine inhibit the pacemaker function of the sinoatrial node and induce cardiac arrest. Pre-incubation of receptor antagonists is known to inhibit the cardiac arrest induced by these agonists; however, the effect of antagonist administration after established cardiac arrest has not been described. Therefore, we assessed whether specific receptor antagonists could revert cardiac arrest induced by adenosine and muscarinic receptors activation.

The Effect of Raddi (Anacardiaceae) Bark Extract on Histamine-Induced Paw Edema and Ileum Smooth Muscle Contraction.

Raddi (Anacardiaceae), popularly known as red aroeira, is used in traditional medicine to treat inflammatory, gastric, and respiratory disorders. The aim of this study was to evaluate the antihistaminic activity of bark extract by using in vivo and in vitro experimental models. The effects of were investigated on contractions induced by histamine, carbachol, and potassium chloride in isolated guinea pig ileum.

Factors influencing biased agonism in recombinant cells expressing the human α -adrenoceptor.

Background And Purpose: Agonists acting at GPCRs promote biased signalling via Gα or Gβγ subunits, GPCR kinases and β-arrestins. Since the demonstration of biased agonism has implications for drug discovery, it is essential to consider confounding factors contributing to bias. We have examined bias at human α -adrenoceptors stably expressed at low levels in CHO-K1 cells, identifying off-target effects at endogenous receptors that contribute to ERK1/2 phosphorylation in response to the agonist oxymetazoline.

Effects of in vitro, acute and chronic treatment with fluoxetine on the sympathetic neurotransmission of rat vas deferens.

It is described that fluoxetine treatment is able to induce ejaculatory disorders. However, the exact mechanism is still not fully understood. Therefore, this study was carried out to further evaluate the anti-ejaculatory effects of fluoxetine, using different approaches (in vitro or in vivo treatments), on the sympathetic neurotransmission of the rat vas deferens.

Would calcium or potassium channels be responsible for cardiac arrest produced by adenosine and ATP in the right atria of Wistar rats?

Autonomic nerves release ATP, which is processed into adenosine in the synaptic cleft. Adenosine and ATP exert a negative chronotropic effect in the heart. This study aims to evaluate adenosine and P2 receptors and cellular signalling in cardiac arrest produced by purines in the heart.

Could α1-adrenoceptors and androgen receptors be modified by sexual maturation and testosterone in the rat testicular capsule?

Aims: Testicular capsule contractile dysfunctions are recognized to contribute to male infertility, but the influence of sexual maturation and exogenous testosterone on the expression and function of androgen receptor and α1-adrenoceptors on rat testicular capsule is unclear. Here, these two biological parameters were evaluated on testicular capsule from sexually immature and young adult rats treated or not with exogenous testosterone.

Main Methods: Male Wistar rats (45- and 60-day-old) were assigned into groups: control (saline 0.

A comparison of histamine effects on the sympathetic neurotransmission of testicular capsule and rat vas deferens.

Histamine is an important modulatory agent of the sympathetic neurotransmission, but its exact action on the testicular capsule or rat vas deferens is not fully understood. The present study sought to further investigate the functional effects of histamine on the neuronal and exogenous noradrenaline-induced contraction of the testicular capsule and rat vas deferens as well as to evaluate the contractile properties of this drug. The testicular capsule or vas deferens from Wistar rats, 3-4 months old, weighing 300-400 g, was isolated and mounted in organ baths for functional experiments.

Increase of angiotensin-converting enzyme activity and peripheral sympathetic dysfunction could contribute to hypertension development in streptozotocin-induced diabetic rats.

Diabetes augments the risk of hypertension. Although several factors have been implicated in the development of such hypertensive state, we designed this study to investigate blood pressure development, the activity of angiotensin-converting enzyme (ACE) in blood as well as sympathetic neurotransmission in the vas deferens of diabetic rats. We used streptozotocin (STZ)-induced diabetic rats (60 mg/kg) in order to evaluate the systolic blood pressure (SBP), ACE activity and peripheral sympathetic neurotransmission.

Functional characterization of acetylcholine receptors and calcium signaling in rat testicular capsule contraction.

The motor activity of mammalian testicular capsule (TC) contributes to male fertility and infertility, but the acetylcholine receptors related to the contractions induced by cholinergic drugs are poorly known. Indeed to characterize the acetylcholine receptors and cellular signaling by Ca(2+) involved in TC motor activity of rats, the potency of agonists (pD₂) and antagonists (pA₂) of acetylcholine receptors, and effects of Ca(2+) cellular transport blockers on the cholinergic contractions were evaluated. pD₂ values of acetylcholine (5.

Changes of cytosolic calcium and contractility of young rat vas deferens by acute treatment with amphetamine, fluoxetine or sibutramine.

Previous studies conducted in our laboratory indicated that administration of amphetamine, fluoxetine or sibutramine affects the sympathetic nervous system of the rat vas deferens. Therefore, our goal was to verify the role of calcium in vasa deferentia from young rats pretreated with a single dose of these drugs. Young 40-day-old male Wistar rats were pretreated with amphetamine 3 mg/kg, fluoxetine 10 mg/kg or sibutramine 6 mg/kg for 4 h before the experiments.