Browsing by Subject "Norepinephrine"
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Item The Anatomical Distribution Patterns, Physiological Effects, and Quantification of Biogenic Amines in the Central Nervous Systems of Araneae and Scorpiones (Arthropoda: Chelicerata)(2019-08) Auletta, AnthonyThe arthropod subphylum Chelicerata is one of the most diverse groups of organisms on the planet, and yet relatively little is known about the structural and functional organization of chelicerate central nervous systems (CNSs). To address this knowledge gap, I conducted a comparative study of biogenic amines in the CNSs of three representative chelicerates: the wolf spider Hogna lenta (Araneae: Lycosidae), the jumping spider Phidippus regius (Araneae: Salticidae), and the bark scorpion Centruroides sculpturatus (Scorpiones: Buthidae). In H. lenta and P. regius, I mapped the anatomical distribution of catecholaminergic neurons (i.e., those that produce dopamine [DA] or norepineprhine [NE]) in the CNS, using an antiserum against tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine synthesis. TH immunoreactivity was detected throughout the spider CNS, including in the visual system, the arcuate body (a site of sensorimotor integration), and the neuromeres of the appendages and opisthosoma, thus suggesting that catecholamines play vital roles in many different behaviors and other physiological processes in spiders. Using similar immunocytochemical methods, I also described the distribution of catecholaminergic neurons in the ventral nerve cord (VNC) of C. sculpturatus, as well as neurons that contain octopamine (OA) and serotonin (5-hydroxytryptamine, 5-HT). Of particular note in the scorpion were clusters of large efferent TH-ir neurons, which exited the CNS to directly innervate the tissues of the book lungs, implying a role for catecholaminergic modulation of respiratory functions. These studies include the first description of catecholamines in any chelicerate taxon, and provide a much-needed foundation upon which future functional studies of biogenic amines in chelicerates can be based. Additionally, I utilized a combination of immunocytochemistry, quantitative chemistry, electrophysiology, and bioinformatics techniques to examine the possibility that NE is an endogenous signaling molecule in chelicerates, despite the widespread notion that invertebrates lack NE. Using ultra-performance liquid chromatography and mass spectrometry, I detected non-trace amounts of NE in the CNSs of both C. sculpturatus and H. lenta. Endogenous NE was localized to cells of the supraneural lymphoid glands in the scorpion, which implies a previously unrecognized secretory role for these structures. NE was also shown to elicit robust patterned electrophysiological activity in the terminal nerves of the scorpion, which was distinct from the patterns produced by other amines. Finally, I identified genes for distinct NE, OA, and DA receptors in the C. sculpturatus genome. Taken together, my results support the idea that NE is an endogenous and physiologically active modulator in scorpions, and possibly in the Chelicerata more broadly, thus challenging the idea that adgrenergic signaling is exclusive to the vertebrates. The implications of these findings are discussed in relation to the evolution of aminergic systems within the Arthropoda and the Bilateria as a whole.Item CFTR Genotype, Not Circulating Catecholamines, Influence Cardiovascular Function in Cystic Fibrosis(2015-07) Bisch, AlexanderObjective: Cystic fibrosis (CF) is a genetic disease that elicits affects throughout the body and is characterized by a mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) with direct, well-documented, pulmonary function consequences. It has been shown a single dose of a Beta-agonist increases cardiac output (Q) and stroke volume (SV) and decreases systemic vascular resistance (SVR) in healthy subjects. This effect is attenuated in CF subjects; however, it is unknown if this decreased cardiovascular response to an inhaled drug is due to inherent cardiovascular deficits from CFTR mutation, receptor desensitization from prolonged Beta- agonist use, or inhibited drug delivery to the blood stream due to mucus buildup in the lungs. This study sought to determine the effects of endogenous epinephrine (EPI) and norepinephrine (NE) on cardiovascular function in CF, and to evaluate cardiovascular function according to CFTR mutation [Delta]F508 Ins/DEL). Methods: Eleven CF subjects and 27 healthy control participants completed a cycle ergometery test with measures of Q, SV, SVR, and HR along with plasma measures of EPI and NE. We compared subjects by variables of cardiovascular function relative to EPI and NE, and also based on genetic variants of [Delta]F508 Ins/DEL. Results: CF subjects demonstrated significantly lower Q and SV at 50% of peak exercise and peak exercise than healthy subjects, and a higher SVR at rest, 50% of peak, and peak exercise. Additionally, CF subjects also demonstrated significantly lower Q and SV relative to NE at rest, however there were no differences in HR relative to NE or SVR relative to EPI. When SV was stratified for CFTR mutation type, there were significant differences at rest, 50% of peak exercise, and there was a trend towards significance at peak exercise. Subjects with a double deletion of the [Delta]F508 had lower SV when compared to single deletion subjects. There were moderate and significant correlations found between EPI and SV and EPI and Q, but not in EPI and SVR when the study population was evaluated as a whole. Within the healthy group, there were significant correlations between EPI and SV, and EPI and Q, but none between EPI and SVR. Only correlations between EPI and Q were seen in the CF group. Conclusion: These results demonstrate that CF subjects have lower cardiovascular function parameters. Further, these results suggest that this impairment in cardiovascular function is likely the result of impairment in CFTR function due to CFTR genotype differences of the [Delta]F508, rather than receptor desensitization or inhibited drug delivery.