Red light (670 nm) energy controls vasodilation via the formation of a transferable endothelium-derived nitric oxide (NO)-precursor-containing substance, its intracellular traffic, and exocytosis. Here we investigated the underlying mechanistic effect of oxidative stress on light-mediated vasodilation by using pressure myography on dissected murine arteries and immunofluorescence on endothelial cells. Treatment with antioxidants Trolox and catalase decreased vessel dilation.
View Article and Find Full Text PDFAtmospheric CO and temperature are rising concurrently, and may have profound impacts on the transcriptional, physiological and behavioural responses of aquatic organisms. Further, spring snowmelt may cause transient increases of pCO in many freshwater systems. We examined the behavioural, physiological and transcriptomic responses of an ancient fish, the lake sturgeon (Acipenser fulvescens) to projected levels of warming and pCO during its most vulnerable period of life, the first year.
View Article and Find Full Text PDFAm J Physiol Regul Integr Comp Physiol
August 2024
Obesity in adolescence is increasing in frequency and is associated with elevated proinflammatory cytokines and chronic pain in a sex-dependent manner. Dietary probiotics may mitigate these detrimental effects of obesity. Using a Long-Evans adolescent and adult rat model of overweight (high-fat diet (HFD) - 45% kcal from fat from weaning), we determined the effect of a single-strain dietary probiotic [ 299v (Lp299v) from weaning] on the theoretically increased neuropathic injury-induced pain phenotype and inflammatory cytokines.
View Article and Find Full Text PDFComp Biochem Physiol A Mol Integr Physiol
June 2024
The excretory mechanisms of stenohaline marine osmoconforming crabs are often compared to those of the more extensively characterized euryhaline osmoregulating crabs. These comparisons may have limitations, given that unlike euryhaline brachyurans the gills of stenohaline marine osmoconformers possess ion-leaky paracellular pathways and lack the capacity to undergo ultrastructural changes that can promote ion-transport processes in dilute media. Furthermore, the antennal glands of stenohaline marine osmoconformers are poorly characterized making it difficult to determine what role urinary processes play in excretion.
View Article and Find Full Text PDFIn a recent mechanistic study, octopamine was shown to promote proton transport over the branchial epithelium in green crabs, Carcinus maenas. Here, we follow up on this finding by investigating the involvement of octopamine in an environmental and physiological context that challenges acid-base homeostasis, the response to short-term high pCO exposure (400 Pa) in a brackish water environment. We show that hyperregulating green crabs experienced a respiratory acidosis as early as 6 h of exposure to hypercapnia, with a rise in hemolymph pCO accompanied by a simultaneous drop of hemolymph pH.
View Article and Find Full Text PDFWe have previously established that 670 nm energy induces relaxation of blood vessels via an endothelium derived S-nitrosothiol (RSNO) suggested to be embedded in vesicles. Here, we confirm that red light facilitates the exocytosis of this vasodilator from cultured endothelial cells and increases ex vivo blood vessel diameter. Ex vivo pressurized and pre-constricted facial arteries from C57Bl6/J mice relaxed 14.
View Article and Find Full Text PDFAim: To determine whether the crustacean Rh1 protein functions as a dual CO /ammonia transporter and investigate its role in branchial ammonia excretion and acid-base regulation.
Methods: Sequence analysis of decapod Rh1 proteins was used to determine the conservation of amino acid residues putatively involved in ammonia transport and CO binding in human and bacterial Rh proteins. Using the Carcinus maenas Rh1 protein (CmRh1) as a representative of decapod Rh1 proteins, we test the ammonia and CO transport capabilities of CmRh1 through heterologous expression in yeast and Xenopus oocytes coupled with site-directed mutagenesis.
In spring 2021, a law for the nationwide opening of test centers in Germany was passed. The local health department fulfilled the task of monitoring the test centers that subsequently opened throughout Cologne regarding the infectious and hygienic risks. Inspections were carried out using structured checklists.
View Article and Find Full Text PDFCrustaceans' endocrinology is a vastly understudied area of research. The major focus of the studies on this topic to date has been on the molting cycle (and in particular, the role of crustacean hyperglycemic hormone (CHH)), as well as the role of other hormones in facilitating physiological phenotypic adjustments to salinity changes. Additionally, while many recent studies have been conducted on the acclimation and adaptation capacity of crustaceans to a changing environment, only few have investigated internal hormonal balance especially with respect to an endocrine response to environmental challenges.
View Article and Find Full Text PDFComp Biochem Physiol A Mol Integr Physiol
August 2023
Na/H exchangers are directly involved in a variety of an animal's essential physiological processes such as ionoregulation, acid-base regulation, nitrogenous waste excretion, and nutrient absorption. While nine NHX isoforms have been identified in Caenorhabditis elegans, the physiological importance of each isoform is not understood. The current study aimed to further our knowledge of NHX-3 which has previously been suggested to be involved in the movement of ammonia and acid-base equivalents across the nematode's hypodermis.
View Article and Find Full Text PDFThe orphan transporter hippocampus-abundant transcript 1 (Hiat1) was first identified in the mammalian brain. Its specific substrate specificity, however, has not been investigated to date. Here, we identified and analyzed Hiat1 in a crustacean, the green crab Carcinus maenas.
View Article and Find Full Text PDFComp Biochem Physiol A Mol Integr Physiol
April 2023
The American horseshoe crab, Limulus polyphemus, excretes nitrogenous waste in the form of toxic ammonia across their book gills. The mechanism of this branchial excretion is yet unknown. In the current study, two isoforms of a novel ammonia transporter, LpHIAT1α and LpHIAT1β, have been identified in L.
View Article and Find Full Text PDFComp Biochem Physiol A Mol Integr Physiol
February 2023
Transbranchial transport processes are responsible for the homeostatic regulation of most essential physiological functions in aquatic crustaceans. Due to their widespread use as laboratory models, brachyuran crabs are commonly used to predict how other decapod crustaceans respond to environmental stressors including ocean acidification and warming waters. Non-brachyuran species such as the economically-valuable American lobster, Homarus americanus, possess trichobranchiate gills and epipodites that are known to be anatomically distinct from the phyllobranchiate gills of brachyurans; however, studies have yet to define their potential physiological differences.
View Article and Find Full Text PDFAmmonia excretion in fish excretory epithelia is a complex interplay of multiple membrane transport proteins and mechanisms. Using the model system of zebrafish (Danio rerio) larvae, here we identified three paralogues of a novel ammonia transporter, hippocampus-abundant transcript 1 (DrHiat1), also found in most vertebrates. When functionally expressed in Xenopus laevis oocytes, DrHiat1a and DrHiat1b promoted methylamine uptake in a competitive manner with ammonia.
View Article and Find Full Text PDFComp Biochem Physiol A Mol Integr Physiol
October 2022
Intertidal crustaceans like Carcinus maenas shift between an osmoconforming and osmoregulating state when inhabiting full-strength seawater and dilute environments, respectively. While the bodily fluids and environment of marine osmoconformers are approximately isosmotic, osmoregulating crabs inhabiting dilute environments maintain their bodily fluid osmolality above that of their environment by actively absorbing and retaining osmolytes (e.g.
View Article and Find Full Text PDFDue to increasing anthropogenic impacts, heatwaves and prolonged exposure to elevated concentrations of ammonia (HEA) may occur in aquatic environments as a single stressor or a combination thereof, potentially impacting the physiology of exposed animals. In the current study, common water fleas Daphnia magna were exposed for one week to either a 5°C increase in temperature, an increase of 300 µmol l total environmental ammonia, or to both of these stressors simultaneously. Exposure to elevated temperature caused a decrease in MO, ammonia excretion rates, a downregulation of mRNA coding for key Krebs cycle enzymes and the energy consuming Na/K-ATPase and V-type H-ATPase, as well as the energy distributing crustacean hyperglycemic hormone Rh-protein.
View Article and Find Full Text PDFTargeted muscle reinnervation (TMR) is a clinical intervention that is rapidly becoming common in major limb amputation to prevent or reduce amputation-related pain. However, TMR is much less effective when applied long after injury compared with acute TMR. Since the mechanisms governing pain relief in TMR of amputated nerves are unknown, we developed a preclinical model as a platform for mechanistic examination.
View Article and Find Full Text PDFNitric oxide dependent vasodilation is an effective mechanism for restoring blood flow to ischemic tissues. Previously, we established an murine model whereby red light (670 nm) facilitates vasodilation an endothelium derived vasoactive species which contains a functional group that can be reduced to nitric oxide. In the present study we investigated this vasodilator by measuring blood flow with Laser Doppler Perfusion imaging in mice.
View Article and Find Full Text PDFPreeclampsia is a serious pregnancy disorder which in extreme cases may lead to maternal and fetal injury or death. Preexisting conditions which increase oxidative stress, e.g.
View Article and Find Full Text PDFReef-building corals maintain an intracellular photosymbiotic association with dinoflagellate algae. As the algae are hosted inside the symbiosome, all metabolic exchanges must take place across the symbiosome membrane. Using functional studies in oocytes, immunolocalization, and confocal Airyscan microscopy, we established that Rh (ayRhp1) facilitates transmembrane NH and CO diffusion and that it is present in the symbiosome membrane.
View Article and Find Full Text PDFComp Biochem Physiol A Mol Integr Physiol
May 2022
The effects of feeding (meal of 3% of body mass) on acid-base and nitrogen homeostasis were investigated in the seawater acclimated green shore crab, Carcinus maenas. Feeding did not change gastric fluid pH (~pH 6); however, feeding was associated with a respiratory acidosis. Hemolymph HCO did not increase during this acidosis, although titratable and net acid efflux changed from an uptake to an excretion.
View Article and Find Full Text PDFTissue damage and necrosis from inflammatory processes are a consequence of ischemia reperfusion injury (IRI). In skeletal muscle, ischemia reduces the aerobic energy capacity of muscle cells, leading to adverse biochemical alterations and inflammation. The goal of this study is to show that exposure to near-infrared light (NIR) during a period of ischemia reduces IRI by decreasing necrosis and inflammation in addition to decreasing proinflammatory M1 and increasing protective M2 macrophages.
View Article and Find Full Text PDFComp Biochem Physiol A Mol Integr Physiol
April 2022
Elevation of temperature and CO levels within the world's aquatic environments is expected to cause numerous physiological challenges to their inhabitants. While effects on marine ecosystems have been well studied, freshwater ecosystems have rarely been examined using a dual-stressor approach leaving our understanding of its inhabitants upon these challenges unclear. We aimed to identify the affects of elevated temperature and hypercapnia in isolation and in combination on the metabolic and acid-base regulatory processes of a freshwater crayfish, Procambarus clarkii.
View Article and Find Full Text PDFIntroduction: Peripheral artery disease (PAD) is a highly morbid condition in which impaired blood flow to the limbs leads to pain and tissue loss. Previously we identified 670 nm electromagnetic energy (R/NIR) to increase nitric oxide levels in cells and tissue. NO elicits relaxation of smooth muscle (SMC) by stimulating potassium efflux and membrane hyperpolarization.
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