Cardiovascular effect of preeclampsia upon offspring development: Are (Pro) renin-renin receptor ((P)RR) and gender related?

Objectives: Preeclampsia (PE) is a complication of pregnancy that might increase progeny risk of cardiovascular and metabolic problems, mainly in males. Renin angiotensin aldosterone system is known to be involved. (Pro) renin/renin receptor ((P)RR) has been shown to participate in cardiovascular pathology. The aim of this work was to evaluate (P)RR expression and function upon cardiovascular and renal tissues from PE dams' offspring. Materials and Methods: We used offspring from normal pregnant and preeclamptic rats, evaluating body, heart, aorta and kidney weight, length, and blood pressure along 3 months after birth. Subsets of animals received handle region peptide (HRP) (0.2 mg/Kg, sc). Another group received vehicle. Animals were sacrificed at first, second, and third months of age, tissues were extracted and processed for immunoblot to detect (P)RR, PLZF, ß-catenin, DVL-1, and PKCα. (P)RR and PLZF were also measured by RT-PCR. Results: We found that offspring developed hypertension. Male descendants remained hypertensive throughout the whole experiment. Female animals tended to recover at second month and returned to normal blood pressure at third month. HRP treatment diminished hypertension in both male and female animals. Morphological evaluations showed changes in heart, aorta, and kidney weight, and HRP reverted this effect. Finally, we found that (P)RR, PLZF, and canonical WNT transduction pathway molecules were stimulated by PE, and HRP treatment abolished this increase. Conclusion: These findings suggest that PE can induce hypertension in offspring, and (P)RR seems to play an important role through the canonical WNT pathway and that gender seems to influence this response.

Preeclampsia as a possible risk factor for memory impairment, anxiety- and depressive-like behavior in offspring.

RATIONALE: Preeclampsia is a condition that can affect the health in offspring at adult life. The effect on several systems has been described, but less is known about its effect on neuropsychiatric disorders at early ages. OBJECTIVE: Evaluate the possible relationship of preeclampsia with development of anxiety- and depressive-like behavior, as well as memory impairments in male and female early adolescent offspring from preeclamptic mice. METHODS: Thirty pregnant females were divided into control group receiving vehicle, and preeclampsia group receiving L-NAME in drinking water at a dose of 60 mg/Kg from day 10 of pregnancy until delivery. Offspring was weaned and sexed at 4 weeks after birth. Each group was evaluated using the elevated plus maze test (anxiety- like response), tail suspension test (depressive-like behavior) and the recognition of novel objects test (recognition memory), in addition to the open field test was performance to corroborate their motor activity and validate our results. RESULTS: We found that preeclampsia produces behavioral alterations in offspring, and this effect is dependent on sex. The male offspring from preeclampsia showed an enhancement in the time that mice spend in the close arms in the elevated plus maze test, and longer immobility time in the tail suspension test, compared to the offspring from healthy pregnancies. On the other hand, female offspring from preeclampsia showed a lower percentage of recognition in the memory test compared to offspring from normal pregnancy. CONCLUSIONS: These results suggest that preeclampsia predisposes early adolescent young male offspring to develop anxiety- and depressive-like behavior as well as memory impairment in early adolescent young female offspring.

Early Estrogen Replacement Therapy Attenuates Cardiac Dysfunction Caused by Aging and Ovariectomy in Female Wistar Rats.

BACKGROUND: Cardiovascular diseases (CVDs) are the leading cause of women's mortality, linked to aging and reduced estrogen during menopause. Estrogen replacement therapy (ERT) is suggested for CVDs prevention. Yet, its timing initiation remains contentious. Thus, we aimed to evaluate the effect of early and late estrogen therapy on cardiac function and lipid metabolism in ovariectomized old female Wistar rats. METHODS: Fifty randomized female Wistar rats were included in 5 groups (n = 10, 18 months old): (1) Sham, (2) 10 weeks post ovariectomy (Ovx-10 w), (3) 10 weeks post Ovx + early estrogen replacement therapy (Ovx 10 w-early ERT), (4) 20 weeks post Ovx (Ovx-20 w) and (5) Ovx 20 w-late ERT. Three days (early ERT) or 10 weeks (late ERT) after surgery 17-ß estradiol was given (5 µg/kg/day), and 10 weeks after the start of ERT, we assessed cardiac function by echocardiography, electrocardiography, and cardiac catheterization. Estradiol, cholesterol, triglyceride (TG), high-density lipoprotein (HDL) and low-density lipoprotein (LDL) levels were determined. Cardiac histology was performed with Masson's staining. RESULTS: Ovariectomy (Ovx) increases left ventricle internal systolic diameter (0.4 vs 0.3 cm, *p = 0.020) and decreases shortening fraction (40 vs 54 %, *p = 0.030) regardless of therapy. ERT prevents the increase in left ventricle mass after 10 weeks post-Ovx and the ejection fractionreduction after 20 weeks. Lower P wave amplitudes (18.8 vs 24.2 ms, *p = 0.013) were found in the Ovx-20 w group. A longer duration of the QRS complex after 20 weeks post-Ovx with and without ERT was found (32.5 and 32.1 vs 28.3 ms, *p = 0.003; *p = 0.007). Diastolic blood pressure was higher 20 weeks post-Ovx (86 vs 76 mmHg, *p = 0.047), regardless of ERT. The left ventricle (LV) -dP/dt was decreased in Ovx groups without ERT (-750 vs -1320 mmHg, *p = 0.034). An increase in LV collagen deposition was found in the Ovx 10 w group vs Sham (9.58 vs 4.54 %, *p = 0.028). Early ERT avoids the increase in body weight, cholesterol and LDL caused by Ovx. CONCLUSIONS: Ovariectomy causes time-dependent alterations in lipid metabolism, morphology, electrical activity, and heart contractile function. Early but not late ERT prevents some of these effects.

Timing Matters: Effects of Early and Late Estrogen Replacement Therapy on Glucose Metabolism and Vascular Reactivity in Ovariectomized Aged Wistar Rats.

Cardiovascular disease incidence increases after menopause due to the loss of estrogen cardioprotective effects. However, there are conflicting data regarding the timing of estrogen therapy (ERT) and its effect on vascular dysfunction associated with impaired glucose metabolism. The aim of this work was to evaluate the effect of early and late ERT on blood glucose/insulin balance and vascular reactivity in aged ovariectomized Wistar rats. Eighteen-month-old female Wistar rats were randomized as follows: (1) sham, (2) 10-week postovariectomy (10 w), (3) 10 w postovariectomy+early estradiol therapy (10 w-early E2), (4) 20-week postovariectomy (20 w), and (5) 20-week postovariectomy+late estradiol therapy (20 w-late E2). Early E2 was administered 3 days after ovariectomy and late therapy after 10 weeks, in both groups. 17ß-Estradiol (E2) was administered daily for 10 weeks (5 µg/kg/day). Concentration-response curves to angiotensin II, KCl, and acetylcholine (ACh) were performed. Heart rate (HR), diastolic and systolic blood pressure (DBP and SBP), glucose, insulin, HOMA-IR, and nitric oxide (NO) levels were determined. Higher glucose levels were found in all groups compared to the sham group, except the 20 w-late E2 group. Insulin was increased in all ovariectomized groups compared to sham. The HOMA-IR index showed insulin resistance in all ovariectomized groups, except for the 10 w-early E2 group. The 10 w-early E2 group increased NO levels vs. the 10 w group. After 10 w postovariectomy, the vascular response to KCl and Ach increases, despite early E2 administration. Early and late E2 treatment decreased vascular reactivity to Ang II. At 20-week postovariectomy, DBP increased, even with E2 administration, while SBP and HR remained unchanged. The effects of E2 therapy on blood glucose/insulin balance and vascular reactivity depend on the timing of therapy. Early ERT may provide some protective effects on insulin resistance and vascular function, whereas late ERT may not have the same benefits.

Hyperbaric oxygenation applied before or after mild or hard stress: effects on the redox state in the muscle tissue.

The mechanism is unclear for the reported protective effect of hyperbaric oxygen preconditioning against oxidative stress in tissues, and the distinct effects of hyperbaric oxygen applied after stress. The trained mice were divided into three groups: the control, hyperbaric oxygenation preconditioning, and hyperbaric oxygenation applied after mild (fasting) or hard (prolonged exercise) stress. After preconditioning, we observed a decrease in basal levels of nitric oxide, tetrahydrobiopterin, and catalase despite the drastic increase in inducible and endothelial nitric oxide synthases. Moreover, the basal levels of glutathione, related enzymes, and nitrosative stress only increased in the preconditioning group. The control and preconditioning groups showed a similar mild stress response of the endothelial and neuronal nitric oxide synthases. At the same time, the activity of all nitric oxide synthase, glutathione (GSH) in muscle, declined in the experimental groups but increased in control during hard stress. The results suggested that hyperbaric oxygen preconditioning provoked uncoupling of nitric oxide synthases and the elevated levels of GSH in muscle during this study, while hyperbaric oxygen applied after stress showed a lower level of GSH but higher recovery post-exercise levels in the majority of antioxidant enzymes. We discuss the possible mechanisms of the redox response and the role of the nitric oxide in this process.

Comparative treatment with hyperbaric oxygen therapy in a model of systemic loxoscelism in rats.

Objectives: Spiders of the Loxosceles genus, known as violin spiders, produce venom with dermonecrotic and systemic effects, as it is a species widely distributed in the world, its study represents a high medical relevance. Systemic loxoscelism, which occurs in 1 in 5 cases and is the most frequent in children, can be fatal, so the study of effective therapy is of great relevance. In the present study, we compared different therapeutic options to mitigate the systemic effects of Loxosceles boneti venom in a model in which prepubertal rats were used. Materials and Methods: A model of systemic intoxication by L. boneti venom was provoked in male Wistar rats. Study groups were formed: healthy control, with venom and untreated control, treatment with N-acetylcysteine, and/or hyperbaric oxygenation therapy. Subsequently, pathological analysis of the kidney and lung was performed. The oxidant-antioxidant response was evaluated, and molecular analysis of the COX-1 and COX-2 enzymes was performed. Results: Regenerative changes were observed at the cellular level in both treatments, being more noticeable in the hyperbaric oxygen therapy (HBO) group. The anti-oxidant response was outstanding in the same group. Conclusion: Both treatments offer considerable benefits, however; further studies are needed to provide adequate therapeutics.

Fructose and the Liver.

Chronic diseases represent a major challenge in world health. Metabolic syndrome is a constellation of disturbances affecting several organs, and it has been proposed to be a liver-centered condition. Fructose overconsumption may result in insulin resistance, oxidative stress, inflammation, elevated uric acid levels, increased blood pressure, and increased triglyceride concentrations in both the blood and liver. Non-alcoholic fatty liver disease (NAFLD) is a term widely used to describe excessive fatty infiltration in the liver in the absence of alcohol, autoimmune disorders, or viral hepatitis; it is attributed to obesity, high sugar and fat consumption, and sedentarism. If untreated, NAFLD can progress to nonalcoholic steatohepatitis (NASH), characterized by inflammation and mild fibrosis in addition to fat infiltration and, eventually, advanced scar tissue deposition, cirrhosis, and finally liver cancer, which constitutes the culmination of the disease. Notably, fructose is recognized as a major mediator of NAFLD, as a significant correlation between fructose intake and the degree of inflammation and fibrosis has been found in preclinical and clinical studies. Moreover, fructose is a risk factor for liver cancer development. Interestingly, fructose induces a number of proinflammatory, fibrogenic, and oncogenic signaling pathways that explain its deleterious effects in the body, especially in the liver.

Cannabidiol-mediated RISK PI3K/AKT and MAPK/ERK pathways decreasing reperfusion myocardial damage.

Myocardial ischemia continues to be the first cause of morbimortality in the world; the definitive treatment is reperfusion; however, this action causes additional damage to ischemic myocardial tissue; this forces to seek therapies of cardioprotection to reduce this additional damage. There are many cardioprotective agents; within these, cannabinoids have shown to have beneficial effects, mainly cannabidiol (CBD). CBD is a non psychoactive cannabinoid. To evaluate the effect in experimental models of CBD in myocardial ischemia reperfusion in rats, twelve-week-old male rats have been used. The animals were divides in 3 groups: control(C), ischemia reperfusion (IR) and CBD pretreatment (1/day/5mg/kg /10days). Langendorff organ isolate studies were performed, and the area of infarction was assessed with triphenyl tetrazolium, in addition to molecular analysis of AT1 and AT2 receptors and Akt and Erk proteins and their phosphorylated forms related to RISK pathways. It was observed that there is an improvement with the use of CBD increasing inotropism and cardiac lusitropism, improving considerably the cardiovascular functionality. These could be related to the reduction of the area of infarction and activation of the AT2 receptor and the RISK pathway with absence of activation of the AT2 receptor (these could relate the reduction of the infarct area and the restoration of cardiovascular function with the activation of the AT2 receptor and the RISK pathway with the absence of activation of the AT2 receptor). The use of cannabinoids was shown to have beneficial effects when used as a treatment for myocardial reperfusion damage.

Estrous cycle phase affects myocardial infarction through reactive oxygen species and nitric oxide.

INTRODUCTION: Myocardial infarction is the leading cause of death in women worldwide. Several studies have shown that estrogens play a cardioprotective role in women by decreasing reactive oxygen species (ROS) and increasing nitric oxide (NO). The aim of this work was to determine whether the evolution of myocardial infarction depends on the phase of the estrous cycle. METHODS: Female Wistar rats were randomized into the following groups with an (n = 7 per group): (1) ovariectomized (OVX-sham); (2) OVX-48 h coronary occlusion (CO); (3) OVX-2 w CO; (4) proestrus-sham; (5) proestrus-48 h CO; (6) proestrus-2 w CO; (7) estrus-sham; (8) estrus-48 h CO; and (9) estrus-2 w CO. We measured the percentage of myocardial necrosis, cardiac hypertrophy, hemodynamic parameters, and the production of NO and ROS, after acute and chronic myocardial infarction was induced in proestrus or estrus or ovariectomized female rats. RESULTS: The infarct area was reduced in the proestrus groups, while it was increased in the estrus and OVX groups. The left ventricular systolic pressure (LVSP) and ± dP/dt were reduced, but left ventricular diastolic pressure (LVDP) was increased in the OVX groups. NO was increased in the OVX + CO and estrus + CO groups. Production of ROS was increased in OVX rats after myocardial infarction but remained unchanged in proestrus and estrus. CONCLUSION: The phase of the estrous cycle in which the myocardial infarction occurs is important. When the coronary occlusion occurs during the proestrus phase, it prevents changes in cardiac function, the development of hypertrophy, oxidative stress and changes in NO levels, and reduces the extent of infarction.

Chronic restraint stress induces serotonin transporter expression in the rat adrenal glands.

Chronic restraint stress (CRS) magnifies restraint-induced corticosterone secretion through a mechanism involving increased adrenocortical 5-HT content and turnover. We analysed the impact of CRS on serotonin transporter (SERT) expression and distribution in rat adrenal glands. Male Wistar rats were submitted to CRS (20 min/day) or undisturbed control conditions for 14 days. Exposure to CRS induced a remarkable increase in SERT-like immunoreactivity in the adrenal cortex, which closely matched that of chromogranin A immunostaining, along with a significant increase in SERT protein and mRNA levels in whole adrenals as determined by immunohistochemistry, Western blot and RT-PCR assays, respectively; all these CRS-induced changes occurred almost exclusively in left adrenals. Closely similar results were obtained in animals that received a 14-day chronic corticosterone treatment. These results unravel an interesting association between chronic stress exposure and SERT expression in adrenocortical chromogranin A-positive cells, which seems to be a glucocorticoid-dependent phenomenon.

Preeclampsia as predisposing factor for hypertensive retinopathy: Participation by the RAAS and angiogenic factors.

Preeclampsia (PE) is a hypertensive complication of pregnancy. Its cause is still unknown and it could be a risk factor for future ophthalmic problems. Retinal vascular bed alterations have been described as a consequence of PE, suggesting a retinopathy. Factors related to angiogenesis and vascular permeability, such as vascular endothelial growth factor (VEGF) and pigment epithelium derived factor (PEDF) or components of the renin angiotensin aldosterone system (RAAS), prorrenin/renin receptor ((P)RR) and angiotensin II type I receptor (AT1R) have been located in the retina, participating in other retinopathies, but it is unknown if they could participate in PE. Our aim was to elucidate whether VEGF, PEDF, (P)RR and AT1R could be modified during PE and during hypertension induced in rats with a history of PE. We used female Wistar rats and subrrenal aortic coarctation to induce PE, and after delivery, we induced a second hit by Nω-nitro-L-arginine methyl ester (L-NAME) administration. We measured blood pressure, proteinuria and pups development. In both models, eye fundal exploration and immunoblot for VEGF, PEDF, (P)RR and AT1R were performed. We found that the development of hypertension occurred faster in previously PE rats than in normal animals. VEGF, PEDF, (P)RR and AT1R were increased in PE, but in L-NAME-induced hypertension only (P)RR and AT1R were altered. Eye fundal data indicated that PE induced a level I retinopathy, but L-NAME induced a faster and more severe retinopathy in previously PE animals compared to previously normal pregnancy rats. These results indicate that PE predisposes to development of a faster and more severe retinopathy after a second hit. They also suggest that VEGF and PEDF seem to participate only in PE retinopathy, but in both models, RAAS components seem to have a more critical participation.

Effect of chronic corticosterone treatment on expression and distribution of serotonin 5-HT7 receptors in rat adrenal glands.

Sensitized stress-induced corticosterone (CORT) secretion in chronically stressed rats involves 5-HT7 receptor activation. The effect of 14-day chronic CORT and vehicle (VEH) administration on 5-HT7 receptor expression in adrenal glands, adrenal 5-HT content, and adrenocorticotropic hormone and CORT secretion was analysed. On day 15, VEH- and CORT-treated animals were perfused or decapitated without stress exposure (0 min) or after 10 and 30 min of restraint for collection of trunk blood and tissues. 5-HT7 receptor-like immunoreactivity (5-HT7R-LI), 5-HT7 receptor protein, and mRNA levels were determined by immunohistochemistry, Western blot, and reverse transcription polymerase chain reaction assays, respectively; 5-HT levels and hormones were quantified using HPLC and ELISA kits, respectively. An undisturbed control group was included for most experimental comparisons. Chronic CORT strongly increased 5-HT7R-LI in the outer adrenal cortex, as well as 5-HT7 receptor protein and mRNA in whole adrenal glands; adrenal 5-HT content also increased in these animals. Decreased adrenocorticotropic hormone and CORT secretion at 30 min of restraint occurred in CORT-treated rats. The results support the notion that chronic stress-induced increase of adrenocortical 5-HT7 receptors and adrenal 5-HT content is a glucocorticoid-dependent phenomenon; the development of magnified stress-induced 5-HT7 receptor-mediated CORT responses in chronically stressed animals nevertheless likely involves additional mechanisms.

Liposomes Loaded with Cisplatin and Magnetic Nanoparticles: Physicochemical Characterization, Pharmacokinetics, and In-Vitro Efficacy.

With the aim improving drug delivery, liposomes have been employed as carriers for chemotherapeutics achieving promising results; their co-encapsulation with magnetic nanoparticles is evaluated in this work. The objective of this study was to examine the physicochemical characteristics, the pharmacokinetic behaviour, and the efficacy of pegylated liposomes loaded with cisplatin and magnetic nanoparticles (magnetite) (Cis-MLs). Cis-MLs were prepared by a modified reverse-phase evaporation method. To characterize their physicochemical properties, an evaluation was made of particle size, ζ-potential, phospholipid and cholesterol concentration, phase transition temperature (Tm), the encapsulation efficiency of cisplatin and magnetite, and drug release profiles. Additionally, pharmacokinetic studies were conducted on normal Wistar rats, while apoptosis and the cytotoxic effect were assessed with HeLa cells. We present a method for simultaneously encapsulating cisplatin at the core and also embedding magnetite nanoparticles on the membrane of liposomes with a mean vesicular size of 104.4 ± 11.5 nm and a ζ-potential of -40.5 ± 0.8 mV, affording a stable formulation with a safe pharmacokinetic profile. These liposomes elicited a significant effect on cell viability and triggered apoptosis in HeLa cells.

Parecoxib Increases Blood Pressure Through Inhibition of Cyclooxygenase-2 Messenger RNA in an Experimental Model.

BACKGROUND: Cyclooxygenase-2 selective inhibitors have been developed to alleviate pain and inflammation; however, the use of a selective cyclooxygenase-2 inhibitor is associated with mild edema, hypertension, and cardiovascular risk. AIM: To evaluate, in an experimental model in normotensive rats, the effect of treatment with parecoxib in comparison with diclofenac and aspirin and L-NAME, a non-selective nitric oxide synthetase, on mean arterial blood pressure, and cyclooxygenase-1 and -2 messenger RNA and protein expression in aortic tissue. METHODS: Rats were treated for seven days with parecoxib (10 mg/kg/day), diclofenac (3.2 mg/kg/day), aspirin (10 mg/kg/day), or L-NAME (10 mg/kg/day). Mean arterial blood pressure was evaluated in rat tail; cyclooxygenase-1 and -2 were evaluated by reverse transcription-polymerase chain reaction and Western blot analysis in aortic tissue. RESULTS: Parecoxib and L-NAME, but not aspirin and diclofenac, increased mean arterial blood pressure by about 50% (p < 0.05) without changes in cardiac frequency. Messenger RNA cyclooxygenase-1 expression in aortic tissue was not modified with any drug (p < 0.05). L-NAME and parecoxib treatment decreased messenger RNA cyclooxygenase-2 and cyclooxygenase-2 (p < 0.05). While cyclooxygenase-1 protein decreased with the three drugs tested but not with L-NAME (p < 0.05), the cyclooxygenase-2 protein decreased only with aspirin and parecoxib (p < 0.05). CONCLUSION: Parecoxib increases the blood pressure of normotensive rats by the suppression of COX-2 gene expression, which apparently induced cardiovascular control.

Pharmacological characterization of mechanisms involved in the vasorelaxation produced by rosuvastatin in aortic rings from rats with a cafeteria-style diet.

The present study aimed to investigate the possible influence of several inhibitors and blockers on the vascular effect produced by the acute in vitro application of rosuvastatin to phenylephrine-precontracted aortic rings from rats with a semi-solid, cafeteria-style (CAF) diet. It also aimed to examine the effects of rosuvastatin on the expression of endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase, constitutive cyclooxygenase, and inducible cyclooxygenase in aortic rings from rats with a CAF diet. From comparisons of the effect on phenylephrine-precontracted aortic rings extracted from rats with two different diets (a standard and a CAF diet), it was found that 10(-9) -10(-5) -mol/L rosuvastatin produced lower concentration-dependent vasorelaxation on rings from the CAF diet group. The vasorelaxant effect was unaffected by the vehicle, but it was significantly attenuated by 10(-5) -mol/L N(G) -nitro-l-arginine methyl ester, 10(-2) -mol/L tetraethylammonium, 10(-3) -mol/L 4-aminopyridine, 10(-7) -mol/L apamin plus 10(-7) -mol/L charybdotoxin, 10(-5) -mol/L indomethacin, or 10(-5) -mol/L cycloheximide. Moreover, in aortic rings from rats with a CAF diet, rosuvastatin enhanced the expression of eNOS, inducible nitric oxide synthase, constitutive cyclooxygenase, and inducible cyclooxygenase. The acute in vitro application of rosuvastatin to phenylephrine-precontracted aortic rings from rats with a CAF diet had a vasorelaxant effect. Overall, the present results suggest that the stimulation of eNOS, the opening of Ca(2+) -activated and voltage-activated K(+) channels, the stimulation of prostaglandin synthesis and enhanced protein levels of eNOS, inducible nitric oxide synthase, constitutive cyclooxygenase, and inducible cyclooxygenase are involved in this relaxant effect.

GR-127935-sensitive mechanism mediating hypotension in anesthetized rats: are 5-HT5B receptors involved?

The 5-HT1B/1D receptor antagonist, GR-127935, inhibits hypotensive responses produced by the 5-HT1A, 5-HT1B/1D and 5-HT7 receptor agonist, and 5-HT5A/5B receptor ligand, 5-carboxamidotryptamine (5-CT), in rats. This work further characterized the above mechanism using more selective 5-HT1B and 5-HT1D receptor antagonists. Also, expression of 5-HT5A and 5-HT5B receptor mRNAs in blood vessels was searched by reverse transcription polymerase chain reaction. Decreases in diastolic blood pressure induced by 5-CT (0.001-10 µg/kg, intravenously) were analyzed in anesthetized rats that had received intravenous vehicle (1 mL/kg), SB-224289 (5-HT1B antagonist; 0.3 and 1.0 mg/kg), BRL15572 (5-HT1D antagonist; 0.3 and 1.0 mg/kg), SB-224289 + BRL15572 (0.3 mg/kg, each), or SB-224289 + BRL15572 (0.3 mg/kg, each) + GR-127935 (1 mg/kg). Because only the latter treatment inhibited 5-CT-induced hypotension, suggestive of a mechanism unrelated to 5-HT1B/1D receptors, the effects of antagonists/ligands at 5-HT5A (SB-699551, 1 mg/kg), 5-HT6 (SB-399885, 1 mg/kg), and 5-HT1B/1D/5A/5B/7 receptors (ergotamine, 0.1 mg/kg) on 5-CT-induced hypotension were tested. Interestingly, only ergotamine blocked 5-CT-induced responses; this effect closely paralleled that of SB-224289 + BRL-15572 + GR-127935. Neither did ergotamine nor GR-127935 inhibit hypotensive responses induced by the 5-HT7 receptor agonist, LP-44. Faint but clear bands corresponding to 5-HT5A and 5-HT5B receptor mRNAs in aorta and mesenteric arteries were detected. Results suggest that the GR-127935-sensitive mechanism mediating hypotension in rats is unrelated to 5-HT1B, 5-HT1D, 5-HT5A, 5-HT6, and 5-HT7 receptors. This mechanism, however, resembles putative 5-HT5B receptors.

Caloric restriction modifies both innate and adaptive immunity in the mouse small intestine

Although caloric restriction (CR) apparently has beneficial effects on the immune system, its effects on the immunological function of the intestinal mucosa are little known. The present study explored the effect of CR on the innate and adaptive intestinal immunity of mice. Balb/c mice were either fed ad libitum (control) or on alternate days fed ad libitum and fasted (caloric restriction). After 4 months, an evaluation was made of IgA levels in the ileum, the gene expression for IgA and its receptor (pIgR), as well as the expression of two antimicrobial enzymes (lysozyme and phospholipase A2) and several cytokines of the intestinal mucosa. CR increased the gene expression of lysozyme and phospholipase A2. The levels of IgA were diminished in the ileum, which apparently was a consequence of the reduced transport of IgA by pIgR. In ileum, CR increased the gene expression for most cytokines, both pro- and anti-inflammatory. Hence, CR differentially modified the expression of innate and adaptive immunity mediators in the intestine (AU)

Role of peripheral and spinal 5-HT(3) receptors in development and maintenance of formalin-induced long-term secondary allodynia and hyperalgesia.

The role of peripheral and spinal 5-HT(3) receptors in formalin-induced secondary allodynia and hyperalgesia in rats was assessed. Formalin produced acute nociceptive behaviors (flinching and licking/lifting) followed by long-term secondary mechanical allodynia and hyperalgesia in both paws. In experiments where the test drug was anticipated to augment or antagonize the response, 0.5 or 1% formalin, respectively, was used for injection. Peripheral ipsilateral, but not contralateral, pre-treatment (-10 min) with serotonin (5-HT, 10-100 nmol/paw) and the selective 5-HT(3) receptor agonist 1-(m-chlorophenyl)-biguanide (m-CPBG, 10-300 nmol/paw) increased 0.5% formalin-induced secondary allodynia and hyperalgesia in both paws. Moreover, spinal pre-treatment with m-CPBG (10-300 nmol/rat) increased 0.5% formalin-induced secondary hyperalgesia but not allodynia in both paws. Accordingly, peripheral ipsilateral (30-300 nmol/paw), but not contralateral (300 nmol/paw), and spinal (10-100 nmol) pre-treatment with the selective 5-HT(3) receptor antagonist ondansetron prevented 1% formalin-induced secondary mechanical allodynia and hyperalgesia in both paws. The peripheral pronociceptive effects of 5-HT (100 nmol/paw) and m-CPBG (300 nmol/paw) as well as the spinal effect of m-CPBG (300 nmol/rat) were completely prevented by the peripheral (10 nmol/paw) and spinal (1 nmol/rat) injection, respectively, of ondansetron. At these doses, ondansetron did not modify per se formalin-induced nociceptive behaviors. Spinal (30-300 nmol/rat), but not peripheral (300 nmol/paw), post-treatment (on day 6) with ondansetron reversed established formalin-induced secondary mechanical allodynia and hyperalgesia in both paws. Results suggest that a barrage of afferent input induced by 5-HT at peripheral 5-HT(3) receptors participates in the development of formalin-induced long-term secondary allodynia and hyperalgesia in the rat. In addition, our data suggest that spinal 5-HT(3) receptors play an important role during development and maintenance of these evoked long-term behaviors.

Effect of inter-renal aortic coarctation-induced hypertension on function and expression of vascular α(1A)- and α(1D)-adrenoceptors.

We investigated the effect of inter-renal aortic coarctation on the function and expression of vascular α(1A)- and α(1D)-adrenoceptors and plasma angiotensin II (ATII) in rats. Male Wistar rats, either sham operated (SO), or with aortic coarctation for 7 (AC7) and 14 days (AC14) were used for agonist-induced pressor responses in vehicle (physiological saline)- and antagonist-treated anesthetized animals, immunoblot analysis (α(1A)- and α(1D)-adrenoceptor in aorta and caudal arteries), and immunoassay (plasma ATII). The α(1D)-adrenoceptor antagonist, BMY-7378 (BMY) blocked noradrenaline-induced responses in the order SO > AC7 â‰« AC14; in contrast, the α(1A)-adrenoceptor antagonist RS-100329 (RS), produced a marginal shift to the right of the dose-response curve to noradrenaline, along with a strong decrease of the maximum pressor effect in the order SO > AC7 = AC14. The potency of the α(1A)-adrenoceptor agonist A-61603 increased in rats with AC14, and responses were inhibited by RS in the order AC14 > AC7 > SO. In aorta, α(1D)-adrenoceptor protein increased in AC7 and decreased in AC14; α(1A)-adrenoreceptor protein increased in the caudal artery of AC7 and returned to control values in AC14. Plasma ATII increased in AC7 and AC14, compared with SO rats. These results suggest an early and direct relationship between ATII and α(1D)-adrenoreceptors in the development of hypertension in this experimental model.

Caloric restriction modifies both innate and adaptive immunity in the mouse small intestine.

Although caloric restriction (CR) apparently has beneficial effects on the immune system, its effects on the immunological function of the intestinal mucosa are little known. The present study explored the effect of CR on the innate and adaptive intestinal immunity of mice. Balb/c mice were either fed ad libitum (control) or on alternate days fed ad libitum and fasted (caloric restriction). After 4 months, an evaluation was made of IgA levels in the ileum, the gene expression for IgA and its receptor (pIgR), as well as the expression of two antimicrobial enzymes (lysozyme and phospholipase A2) and several cytokines of the intestinal mucosa. CR increased the gene expression of lysozyme and phospholipase A2. The levels of IgA were diminished in the ileum, which apparently was a consequence of the reduced transport of IgA by pIgR. In ileum, CR increased the gene expression for most cytokines, both pro- and anti-inflammatory. Hence, CR differentially modified the expression of innate and adaptive immunity mediators in the intestine.