Endothelium-dependent relaxation by G protein-coupled receptor 30 agonists in rat carotid arteries

2010 ◽  
Vol 298 (3) ◽  
pp. H1055-H1061 ◽  
Author(s):  
Brad R. S. Broughton ◽  
Alyson A. Miller ◽  
Christopher G. Sobey

Recent studies have identified that the novel membrane estrogen receptor, G protein-coupled receptor 30 (GPR30), is present in blood vessels. However, the signaling mechanisms associated with GPR30 in the vasculature remain unclear. We examined whether putative agonists of GPR30 exert vasorelaxant and/or antioxidant effects similar to those reported for estrogen. Using wire myography, we assessed the role of the endothelium in relaxation responses to the GPR30 agonists, G-1 and 5408-0877 (1 nM-10 μM), in U-46619-precontracted common carotid arteries from Sprague-Dawley rats. Furthermore, using lucigenin (5 μM)-enhanced chemiluminescence, we tested the effect of G-1 (10 μM) on superoxide levels. Specific immunofluorescence was also used to confirm GPR30 expression in the arterial wall. We found that G-1 and 5408-0877 induced a concentration-dependent relaxation in carotid arteries from both male and female rats. Interestingly, G-1- and 5408-0877-induced relaxation was abolished by endothelium removal and abrogated in the presence of the nitric oxide synthase inhibitor NG-nitro-l-arginine methyl ester (100 μM). In addition, G-1 significantly decreased NADPH (100 μM)-stimulated superoxide production by carotid and intracranial (pooled basilar and middle cerebral) arteries but also attenuated the superoxide signal detected in a cell-free xanthine/xanthine oxidase assay. Furthermore, GPR30 immunoreactivity was observed in endothelial and vascular smooth muscle cells of carotid arteries from both genders. These findings indicate that GPR30 is expressed throughout the arterial wall and that GPR30 agonists elicit endothelial-derived nitric oxide-dependent relaxation of the carotid artery in male and female rats. Additionally, G-1 appears to directly scavenge superoxide anion.

2016 ◽  
Vol 94 (4) ◽  
pp. 408-415 ◽  
Author(s):  
Xiaoyuan Han ◽  
Sonali Shaligram ◽  
Rui Zhang ◽  
Leigh Anderson ◽  
Roshanak Rahimian

Hyperglycemia affects male and female vascular beds differently. We have previously shown that 1 week after the induction of diabetes with streptozotocin (STZ), male and female rats exhibit differences in aortic endothelial function. To examine this phenomenon further, aortic responses were studied in male and female rats 8 weeks after the induction of diabetes (intermediate stage). Endothelium-dependent vasodilation (EDV) to acetylcholine (ACh) was measured in phenylephrine (PE) pre-contracted rat aortic rings. Concentration response curves to PE were generated before and after L-NAME, a nitric oxide synthase (NOS) inhibitor. Furthermore, mRNA expression of endothelial nitric oxide synthase (eNOS) and NADPH oxidase subunit (Nox1) were determined. At 8 weeks, diabetes impaired EDV to a greater extent in female than male aortae. Furthermore, the responsiveness to PE was significantly enhanced only in female diabetic rats, and basal NO, as indicated by the potentiation of the response to PE after L-NAME, was reduced in female diabetic rat aortae to the same levels as in males. In addition, eNOS mRNA expression was decreased, while the Nox1 expression was significantly enhanced in diabetic female rats. These results suggest that aortic function in female diabetic rats after 8 weeks exhibits a more prominent impairment and that NO may be involved.


2018 ◽  
Vol 7 (5) ◽  
pp. 412-418
Author(s):  
Mohd Urooj ◽  
◽  
Mohammad Ahmed Khan ◽  
G. Thejaswini ◽  
Munawwar Husain Kazmi ◽  
...  

Jawarish Shahi (JS) is a compound polyherbal Unani pharmacopoeial formulation indicated for Khafqan (Palpitation), Nafkh-e-Shikam (Flatulence) and Waswas (Insanity; false perception and hallucinations). Jawarish Shahi contains herbs like Halela (Terminalia chebula), Amla (Emblica officinalis), Kishneez (Coriandrum sativum), Elaichi Khurd, (Elettaria cardamomum), and Bed Mushk (Salix caprea). The present study was carried out as per OECD 408 guidance to evaluate 90 days repeated oral dose toxicity in male and female Sprague Dawley rats. The study was performed at dose levels 1028 and 2000 mg/kg bw. No adverse effects were reported with respect to body weight, feed intake, behavior and clinical signs indicative of systemic toxicity. The expected growth pattern was observed in body weight and feed intake as compared to control group at both dose levels in male and female rats. There were few significant alterations with respect to hematology, and clinical biochemistry, however the results were within normal range thus considered toxicologically insignificant. The microscopic examination of different organ/tissue showed that no histopathological changes were observed. The findings of the study showed that No Observed Adverse Effect Level (NOAEL) for JS is greater than 2000 mg/kg body weight


2018 ◽  
Vol 25 (3) ◽  
pp. 246 ◽  
Author(s):  
Juraj Laco ◽  
Andrej Barta ◽  
Marina Cebová ◽  
Miroslav Čavojský ◽  
František Simančík ◽  
...  

Endocrinology ◽  
2011 ◽  
Vol 152 (4) ◽  
pp. 1562-1571 ◽  
Author(s):  
Yinyang Bai ◽  
Fei Chang ◽  
Rong Zhou ◽  
Peng-Peng Jin ◽  
Hirokazu Matsumoto ◽  
...  

Abstract Perinatal exposure to environmental levels of bisphenol-A (BPA) impairs sexually dimorphic behaviors in rodents. Kisspeptin neurons in anteroventral periventricular nucleus (AVPV), which plays an important role in the activation of GnRH neurons and the initiation of LH-surge, have been suggested to be sexual dimorphism in rats. This study focused on exploring the influence of a perinatal exposure to an environmental dose of BPA on the development and maturation of male AVPV kisspeptin neurons and hypothalamus-pituitary-gonadal axis. Female rats were injected sc with 2 μg BPA/kg·d from gestation d 10 through lactation d 7. Anatomical and functional changes in AVPV kisspeptin neurons and hypothalamus-pituitary-gonadal axis were examined in prepubertal, pubertal, and adult male rats exposed perinatally to BPA (BPA-rats). Here, we show that in postnatal d (PND)30/50/90 BPA-rats, the number of AVPV kisspeptin-immunoreactive cells was persistently increased in comparison with age-matched control male rats. The number of GnRH-immunoreactive cells in PND30 BPA-rats declined approximately 40% compared with control male rats, whereas that in PND50/90 BPA-rats was increased in a G protein-coupled receptor 54-dependent manner. Estradiol could induce a stable LH-surge in PND90 BPA-rats and control female rats, which was sensitive to the G protein-coupled receptor 54 inhibitor. In PND30/50 BPA-rats, plasma level of LH was higher, but the level of testosterone was lower than control male rats. These findings provide evidence that perinatal exposure to an environmental dose of BPA causes a sustained increase in AVPV kisspeptin neurons in male rats, leading to the generation of estradiol-induced LH-surge system.


2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Sang Hyun Park ◽  
Kannampalli Pradeep

The main objective of this investigation was to determine the absorption, distribution, excretion, and pharmacokinetics of the antimalarial drug pyronaridine tetraphosphate (PNDP) in Sprague-Dawley rats. Following oral administration of a single dose (10 mg/Kg) ofC-PNDP, it was observed that the drug was readily absorbed from the small intestine within 1 hour following oral administration and was widely distributed in most of the tissues investigated as determined from the observed radioactivity in the tissues. The peak value of the drug in the blood was reached at around 8 hours postadministration, and radioactivity was detected in most of the tissues from 4 hours onwards.C-PNDP showed a poor permeability across the blood-brain barrier, and the absorption, distribution, and excretion ofC-PNDP were found to be gender-independent as both male and female rats showed a similar pattern of radioactivity. Excretion of the drug was predominantly through the urine with a peak excretion post 24 hours of administration. A small amount of the drug was also excreted in the feces and also in the breath. It was found that theCmax, AUC (0-inf), andTmaxvalues were similar to those observed in the Phase II clinical trials of pyronaridine/artesunate (Pyramax) conducted in Uganda.


2019 ◽  
Vol 8 (3) ◽  
pp. 203-216 ◽  
Author(s):  
Anna C Simcocks ◽  
Kayte A Jenkin ◽  
Lannie O’Keefe ◽  
Chrishan S Samuel ◽  
Michael L Mathai ◽  
...  

Atypical cannabinoid compounds O-1602 and O-1918 are ligands for the putative cannabinoid receptors G protein-coupled receptor 55 and G protein-coupled receptor 18. The role of O-1602 and O-1918 in attenuating obesity and obesity-related pathologies is unknown. Therefore, we aimed to determine the role that either compound had on body weight and body composition, renal and hepatic function in diet-induced obesity. Male Sprague–Dawley rats were fed a high-fat diet (40% digestible energy from lipids) or a standard chow diet for 10 weeks. In a separate cohort, male Sprague–Dawley rats were fed a high-fat diet for 9 weeks and then injected daily with 5 mg/kg O-1602, 1 mg/kg O-1918 or vehicle (0.9% saline/0.75% Tween 80) for a further 6 weeks. Our data demonstrated that high-fat feeding upregulates whole kidney G protein receptor 55 expression. In diet-induced obesity, we also demonstrated O-1602 reduces body weight, body fat and improves albuminuria. Despite this, treatment with O-1602 resulted in gross morphological changes in the liver and kidney. Treatment with O-1918 improved albuminuria, but did not alter body weight or fat composition. In addition, treatment with O-1918 also upregulated circulation of pro-inflammatory cytokines including IL-1α, IL-2, IL-17α, IL-18 and RANTES as well as plasma AST. Thus O-1602 and O-1918 appear not to be suitable treatments for obesity and related comorbidities, due to their effects on organ morphology and pro-inflammatory signaling in obesity.


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