Insights Into Antioxidant Strategies to Counteract Radiation-Induced Male Infertility.

Radiotherapy, which employs ionizing radiation to destroy or prevent the multiplication of tumor cells, has been increasingly used in the treatment of neoplastic diseases, especially cancers. However, radiation collaterally leads to prolonged periods of sperm count suppression, presumably due to impaired spermatogenesis by depleting the germ cell pool, which has long-term side effects for male reproduction. Studies of antioxidant compounds as a potential strategy for male fertility preservation have been performed mainly from animal models, aiming to prevent and restore the male germinal tissue and its function, particularly against the oxidative stress effects of radiation.

Losartan Attenuates Radiation-Induced Damage on Testes and Accelerates Tubular Regeneration.

Male germ cells are particularly susceptible to radiation; infertility being a common consequence after radiotherapy as it impairs spermatogenesis. This study aimed to test whether treatment with losartan (LOS), a selective antagonist of angiotensin II receptor subtype 1 (AT1R), can prevent or attenuate the acute and long-term radiation-induced damage to testes. Wistar rats were randomly distributed into six groups, three of which were studied on day 2 after irradiation: control (CTRL 2), irradiated non-treated (IR 2), and irradiated and treated with LOS (IRLOS 2); and three other groups that were studied on day 60 after irradiation: control (CTRL 60), irradiated non-treated (IR 60), and irradiated and treated with LOS (IRLOS 60).

Orchiectomy but not adjuvant-induced arthritis induces structural modifications in rat aortas.

Purpose: This study aimed to verify whether Adjuvant-Induced Arthritis (AIA) and/or Orchiectomy (ORX) modify the expression of the Nox1, Nox2 and Nox4 isoforms, the endothelial function or the structure of rat aortas.

Methods: Sixty-three Wistar rats were distributed into four groups: 1) Control; 2) ORX; 3) AIA; 4) Orchiectomy plus to Arthritis-induction (ORX/AIA). Thus, 21 days after the onset of AIA (by intradermal injection of Mycobacterium tuberculosis), the presence of Nox1, Nox2 and Nox4, the acetylcholine (ACh)-induced relaxation and the media layer thickness were assessed in the aorta taken from these animals.

Influence of galantamine in the inflammatory process and tissular lesions caused by Trypanosoma cruzi QM2 strain.

Introduction: Trypanosoma cruzi infection triggers an inflammatory process with exacerbated production of cytokines that stimulate inflammatory and anti-inflammatory signals, including the efferent anti-inflammatory signal known as the anti-inflammatory cholinergic pathway. Thus, the use of anticholinesterase drugs, such as galantamine, could minimize the inflammatory process caused by this disease.

Methods: For the study at 30, 60, and 90 days, 120 Swiss mice were divided into three groups.

Angiotensin involvement in kidney injury induced by rheumatoid arthritis in rat.

Renal injury induced by rheumatoid arthritis is not clear and may be related to the angiotensin II. We aim to investigate the adjuvant-induced arthritis (AIA) injury in rat kidney, focusing the angiotensin II/AT pathway. Male Wistar rats were allocated in to three groups: Control, AIA and AIA plus losartan.

Exercise-Induced Modulation of Angiotensin II Responses in Femoral Veins From 2-Kidney-1-Clip Hypertensive Rats.

The present study investigated the angiotensin II (Ang II) responses in rat femoral veins taken from 2-kidney-1clip (2K1C) hypertensive rats at 4 weeks after clipping, as well as the effects of exercise on these responses. In this manner, femoral veins taken from 2K1C rats kept at rest or exposed to acute exercise or to exercise training were challenged with Ang II or endothelin-1 (ET-1) in organ bath. Simultaneously, the presence of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) were determined in these preparations by western blotting.

Exercise training attenuates angiotensin II-induced vasoconstriction in the aorta of normotensive but not hypertensive rats.

New Findings: What is the central question of this study? What are the effects of exercise on Ang II-induced vasoconstriction in aortas of normotensive rats and how do these effects occur in two-kidney-one-clip hypertensive animals? What is the main finding and its importance? In two-kidney rats, exercise training improves the Ang II-induced vasoconstriction by endothelium-derived NO released through AT R activation. This effect of exercise training on the Ang II-induced vasoconstriction is blunted in two-kidney-one-clip hypertensive animals, possibly as a consequence of oxidative stress.

Abstract: This study investigated the effects of both acute exercise and training on the Ang II-induced vasoconstriction in aorta of normotensive (two-kidney; 2K) and two-kidney-one-clip (2K1C) hypertensive rats, focusing on endothelial mechanisms related to nitric oxide (NO) and prostanoids.

Effects of Green and Ripe Coffee in the Metabolic Profile and Muscle Enzymes in Animals Practicing Physical Exercise.

Many studies have shown that plants can be therapeutic alternatives in the prevention or treatment of various diseases. Among these, green coffee may present different pharmacological effects related to the regulation of glycemia and lipid metabolism and is related to the prevention of cardiovascular diseases. The objective of our study was to evaluate the effects of using green and ripe coffee on the metabolic profile and muscular enzymes after the practice of physical exercises in Wistar rats.

Rivastigmine prevents injury induced by ischemia and reperfusion in rat liver.

Purpose: To evaluate whether pre-treatment with rivastigmine is able to attenuate the I/R induced lesions in rat liver.

Methods: SHAM animals or those submitted to I/R, non-treated or pre-treated with rivastigminine (2mg/kg) either 50 or 15 minutes before ischemia, were used. After I/R protocol, these animals were killed and their livers were harvested to measurement of the mitochondrial swelling as well as the malondialdehyde (MDA), nitrite and nitrate tissue concentration.

Influence of the AT1 Receptor Antagonists Telmisartan and Losartan on Reproduction and Offspring After Paternal Exposure to Ionizing Radiation.

This study evaluated the repercussions of paternal exposure to radiation on reproduction and offspring in rats, as well as whether treatment with the angiotensin II type 1 (AT1) receptor antagonists telmisartan and losartan has a mitigating effect. Rats were randomly divided into 6 groups: control, radiation, telmisartan, losartan, radiation + telmisartan, and radiation + losartan. A single 5 Gy dose of radiation was administered directly into the scrotum, followed by treatment with telmisartan (12 mg/kg/d) or losartan (34 mg/kg/2 times per day) for 60 days in the groups receiving these medications.

Prior intake of Brazil nuts attenuates renal injury induced by ischemia and reperfusion.

Introduction: Ischemia-reperfusion (IR) injury results from inflammation and oxidative stress, among other factors. Because of its anti-inflammatory and antioxidant properties, the Brazil nut (BN) might attenuate IR renal injury.

Objective: The aim of the present study was to investigate whether the intake of BN prevents or reduces IR kidney injury and inflammation, improving renal function and decreasing oxidative stress.

Effects of telmisartan and losartan on irradiated testes.

Aims: To analyze the effects of radiation on the reproductive tissue of male Wistar rats and to evaluate whether treatment with the Ang II AT1 receptor antagonists telmisartan and losartan mitigate the dysfunctions resulting from this exposure.

Main Methods: Rats were randomly divided into groups: Control, Irradiated, Telmisartan, Losartan, Irradiated+Telmisartan, and Irradiated+Losartan. Single dose of 5Gy was administered directly into the scrotum, followed by treatment with telmisartan (12mg/kg/day) or losartan (34mg/kg/two times/day) for 60days.

Dipteryx alata Vogel May Improve Lipid Profile and Atherogenic Indices in Wistar Rats Dipteryx alata and Atherogenic Indices.

Worldwide prevalence of noncommunicable chronic degenerative diseases is among the main causes of death worldwide. The consumption of some foods such as nuts and seeds may be beneficial in preventing these diseases. Dipteryx alata Vogel (DA), known popularly as Baru, belongs to the family Fabaceae and is a native fruit tree from the Brazilian savanna.

Effects of Continuous and Accumulated Exercise on Endothelial Function in Rat Aorta.

Background:: The practice of exercise in short bouts repeated throughout the day may be an alternative strategy to lift people out of physical inactivity.

Objective:: to evaluate if accumulated exercise, as occurs in continuous exercise training, improve endothelial function in rat aorta.

Methods:: Wistar male rats were divided into three groups: continuous exercise (CEx, 1 hour on the treadmill) or accumulated exercise (AEx, 4 bouts of 15 minutes / day) for 5 days/week for 8 weeks, or sedentary (SED).

Prostanoids counterbalance the synergism between endothelin-1 and angiotensin II in mesenteric veins of trained rats.

Exercise-induced adaptations of the modulating mechanisms that influence the angiotensin (Ang II) responses assume different features depending on the venous bed. In femoral veins, exercise mobilizes vasodilator prostanoids to cooperate with NO in order to maintain reduced Ang II responses. On the other hand, exercise's influence on the Ang II responses in veins that drain blood from the mesenteric region has been poorly described.

Norepinephrine responses in rat renal and femoral veins are reinforced by vasoconstrictor prostanoids.

Norepinephrine (NE) responses are larger in renal and femoral veins compared to phenylephrine (PE). These differences may be due to the subtypes of adrenoceptor involved in these responses or to the involvement of local modulatory mechanisms. Therefore, the present study investigated in organ bath the adrenoceptor subtypes involved in the NE and PE responses in both renal and femoral veins as well as the influence of local mechanisms related to NO and to prostanoids upon these responses.

Endothelial AT₁ and AT₂ pathways in aortic responses to angiotensin II after stress and ethanol consumption in rats.

Stress and ethanol are important cardiovascular risk factors. Their vascular and blood pressure (BP) effects were evaluated alone and in combination. Adult male Wistar rats (8-10 per group) were separated into control, ethanol (ethanol 20% in drinking water for 6 weeks), stress (restraint 1 h/d 5 d/week for 6 weeks), and ethanol/stress (in combination) groups.

Effects of hyperbaric oxygen therapy as hepatic preconditioning in rats submitted to hepatic ischemia/reperfusion injury.

Purpose: To analyze the role of hyperbaric oxygen therapy as hepatic preconditioning in rats submitted to hepatic ischemia and reperfusion.

Methods: Wistar rats were randomly divided into three groups: SHAM, rats submitted to surgical stress without hepatic ischemia and reperfusion, I/R, rats submitted to total hepatic pedicle ischemia for 30 min, followed by 5 min of reperfusion; HBOI/R, rats submitted to 60 minutes of hyperbaric oxygen therapy at 2 atm and immediately submitted to the experimental protocol of ischemia and reperfusion. Liver function was assessed by measuring serum alanine aminotransferase and aspartate aminotransferase, as well as mitochondrial function by determining states 3 and 4 of mitochondrial respiration, respiratory control rate and mitochondrial permeability transition (mitochondrial swelling).

The enigmatic role of cholinergic reflex in the pathogenesis of Chagas disease.

This study evaluated the inflammatory process in the colons of mice infected with Trypanosoma cruzi QM2 strain, through the analysis of muscle reactivity and the measurement of butyrylcholinesterase (BuChE) in plasma. "Swiss" mice were infected with T. cruzi QM2 strain and after 15 (G15), 30 (G30), 60 (G60), 90 (G90), and 210 (G210) days, each group had blood collected for the measurement of butyrylcholinesterase plasma concentrations ([BuChE]), a measure which functioned as an indicator of plasmatic Ach levels.

Stress alone or associated with ethanol induces prostanoid release in rat aorta via alpha2-Adrenoceptor.

Background: Stress and ethanol are both, independently, important cardiovascular risk factors.

Objective: To evaluate the cardiovascular risk of ethanol consumption and stress exposure, isolated and in association, in male adult rats.

Methods: Rats were separated into 4 groups: Control, ethanol (20% in drinking water for 6 weeks), stress (immobilization 1h day/5 days a week for 6 weeks) and stress/ethanol.

Orchidectomy enhances the expression of endothelin-1 and ETB receptors in rat portal vein.

Functional studies have shown that orchidectomy increases the effects of phenylephrine on rat portal veins, but that it is completely prevented in the presence of both ETA and ETB receptor antagonists. Although it suggests the involvement of endothelin-1 (ET-1), the local production of this vasoactive peptide has not been directly quantified in portal veins. Therefore, the aim of the present study was to verify if orchidectomy increases the local expression of ET-1 as well as ETA and ETB receptors in the rat portal vein.

Exercise reduces angiotensin II responses in rat femoral veins.

The control of blood flow during exercise involves different mechanisms, one of which is the activation of the renin-angiotensin system, which contributes to exercise-induced blood flow redistribution. Moreover, although angiotensin II (Ang II) is considered a potent venoconstrictor agonist, little is known about its effects on the venous bed during exercise. Therefore, the present study aimed to assess the Ang II responses in the femoral vein taken from sedentary and trained rats at rest or subjected to a single bout of exercise immediately before organ bath experiments.

Involvement of the AT1 receptor in the venoconstriction induced by angiotensin II in both the inferior vena cava and femoral vein.

Although angiotensin II-induced venoconstriction has been demonstrated in the rat vena cava and femoral vein, the angiotensin II receptor subtypes (AT(1) or AT(2)) that mediate this phenomenon have not been precisely characterized. Therefore, the present study aimed to characterize the pharmacological receptors involved in the angiotensin II-induced constriction of rat venae cavae and femoral veins, as well as the opposing effects exerted by locally produced prostanoids and NO upon induction of these vasomotor responses. The obtained results suggest that both AT(1) and AT(2) angiotensin II receptors are expressed in both veins.

Exercise increases the angiotensin II effects in isolated portal vein of trained rats.

Training in rats adapts the portal vein to respond vigorously to sympathetic stimuli even when the animal is re-exposed to exercise. Moreover, changes in the exercise-induced effects of angiotensin II, a potent venoconstrictor agonist, in venous beds remain to be investigated. Therefore, the present study aimed to assess the effects of angiotensin II in the portal vein and vena cava from sedentary and trained rats at rest or submitted to an exercise session immediately before organ bath experiments.

Orchidectomy enhances the effects of phenylephrine in rat isolated portal vein.

1. Orchidectomy results in long-term testosterone deprivation similar to that observed in male clinical pathologies, such as hypogonadism and age-related reductions in plasma testosterone concentrations. Although the vascular effects of these sorts of hormone deprivations are known in arteries, they have not been studied to the same extent in veins.