This study tested the hypothesis that exogenous infusion of angiotensin II (ANG II) leads to the release of catecholamines [norepinephrine (NE) and epinephrine (EPI)] into the cardiac interstitial fluid (ISF) space of dogs with adrenals intact (AI) (n = 7) and with adrenals clamped (AC) (n = 5). LV ISF samples were collected at 3-min intervals during administration of ANG II (100 μM ANG II at 1 ml/min for 10 min) to right atrial neurons via their local arterial blood supply and during electrical stimulation of the stellate ganglia of open-chest anesthetized dogs. In AI dogs, ANG II caused ISF NE to increase fivefold (P < 0.05) without a significant increase in coronary sinus (CS) NE. Electrical stimulation (5 ms, 4 Hz, 8-14 V, and 10 min) of the stellate ganglia caused a similar increase in ISF NE (P < 0.05), accompanied by a sevenfold increase in CS NE (P < 0.05). ISF EPI increased greater than sixfold during ANG II infusion (P < 0.05) and during stellate stimulation. However, during ANG II infusions, aorta plasma EPI levels increased fourfold in AI dogs, whereas in AC dogs, CS NE and EPI levels were unaffected during ANG II infusions. Nevertheless, baseline ISF NE and EPI did not differ and increased to a similar extent during ANG II infusions in AI versus AC dogs. Thus exogenously administered ANG II increases the amount of NE liberated into the ISF independent of the adrenal contribution, the amount matching that induced by electrical stimulation of all cardiac sympathetic efferent neurons. In contrast, NE spillover into the CS occurred only during electrical stimulation of stellate ganglia. NE release and uptake mechanisms within the myocardium are differently affected, depending on how the final common pathway of the sympathetic efferent nervous system is modified.

The currents generated by excitatory and inhibitory synapses on motoneurons can be amplified by noradrenalin and serotonin. Both of these neurotransmitters act, and interact, via the same Gq-protein second-messenger system to modulate L-type Ca++, persistent-Na+, and leak K+ channels on motoneuron dendrites. However, noradrenergic and serotonergic synapses only modulate nearby excitatory and inhibitory synapses, so their relative distributions play a major role in the regulation of the overall output of the motoneuron. Moreover, the relative proximity between noradrenergic and serotonergic synapses may allow their individual effects to combine nonlinearly when co-activated, thereby regulating the magnitude of the amplification. The goal of the present study is to determine whether the distributions of noradrenergic and serotonergic synapses are biased along motoneuron dendritic trees. The dendritic trees of five intracellularly stained feline splenius motoneurons were reconstructed. On them were plotted the locations of noradrenergic and serotonergic contacts, as determined by immunohistochemistry. The distribution of noradrenergic contacts was moderately biased both dorsally and distally in all five cells. Serotonergic contacts on the same neurons showed a moderate ventral bias. These findings suggest that excitatory and inhibitory inputs located dorsally and/or distally are preferentially amplified by noradrenergic synapses. Also, those synapses which are located ventrally are favorably amplified by serotonergic synapses. Both serotonergic and noradrenergic contacts are strongly biased towards innervation along small diameter (<2μm) dendrites. The relative distributions between serotonergic and noradrenergic contacts have also been analyzed for all five cells. There was a bias towards minimizing the distance between like contacts (NE to NE and 5-HT to 5-HT). This increases the likelihood of interaction within populations when contacts are co-activated. Conversely, the distances between neighbouring noradrenergic and serotonergic contacts (NE to 5-HT and 5-HT to NE) were biased towards greater separation. This decreases the likelihood of interaction between populations when contacts are co-activated. In summary, these findings suggest that noradrenalin and serotonin, having different location biases along the dendritic tree, will amplify some synapses in a biased manner. Additionally, like synapses may work in a coordinated manner with respect to their relative proximity. Coordination between noradrenergic and serotonergic synapses is less likely. / Thesis (Master, Neuroscience Studies) -- Queen's University, 2008-09-29 09:59:38.799

Thesis (M.S.)--Case Western Reserve University, 2008. / [School of Medicine] Department of Biochemistry. Includes bibliographical references.

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The norepinephrine transporter (NET) plays a pivotal role in terminating noradrenergic signaling and conserving norepinephrine (NE) through the process of re-uptake. Recent evidence suggests a close association between NE release and regulation of NET function. The present study evaluated the relationship between release and uptake, and the cellular mechanisms that govern these processes. KCl stimulation of PC12 cells robustly increased [ H]NE uptake via the NET and simultaneously increased [ H]NE release. KCl-stimulated increases in uptake and release were dependent on Ca . Treatment of cells with phorbol-12-myristate-13-acetate (PMA) or okadaic acid decreased [ H]NE uptake but did not block KCl-stimulated increases in [ H]NE uptake. In contrast, PMA increased [ H]NE release and augmented KCl-stimulated release, while okadaic acid had no effects on release. Inhibition of Ca -activated signaling cascades with KN93 (a Ca calmodulin-dependent kinase inhibitor), or ML7 and ML9 (myosin light chain kinase inhibitors), reduced [ H]NE uptake and blocked KCl-stimulated increases in uptake. In contrast, KN93, ML7 and ML9 had no effect on KCl-stimulated [ H]NE release. KCl-stimulated increases in [ H]NE uptake were independent of transporter trafficking to the plasma membrane. While increases in both NE release and uptake mediated by KCl stimulation require Ca , different intracellular mechanisms mediate these two events.

Wong Kwok Kui Wister. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1992. / Includes bibliographical references (leaves 220-236). / ABSTRACT --- p.1 / OBJECTIVES FOR PROJECT --- p.4 / ABBREVIATIONS --- p.6 / Chapter CHAPTER 1 --- INTRODUCTORY LITERATURE REVIEWS / Chapter 1.1 --- Noradrenaline and adrenaline / Chapter 1.1.1 --- History --- p.8 / Chapter 1.2 --- The adrenal medulla / Chapter 1.2.1 --- The anatomy and microcirculation of the adrenal medulla --- p.10 / Chapter 1.2.2 --- Neuro-endocrine control of adrenal medullary secretion --- p.12 / Chapter 1.3 --- Dopamine / Chapter 1.3.1 --- Introduction --- p.14 / Chapter 1.3.2 --- Levels of DA in plasma and urine --- p.14 / Chapter 1.3.3 --- Origins of DA in the urine --- p.15 / Chapter 1.3.4 --- Control of renal DA production --- p.16 / Chapter 1.3.5 --- The actions of DA in the body --- p.17 / Chapter 1.3.6 --- The DA hypothesis --- p.17 / Chapter 1.3.7 --- Urinary NA and AD --- p.18 / Chapter 1.4 --- ACE inhibitors / Chapter 1.4.1 --- Brief review of the pharmacology of ACE inhibitors --- p.19 / Chapter 1.5 --- Catecholamine assays / Chapter 1.5.1 --- Introduction --- p.21 / Chapter 1.5.2 --- Chemistry --- p.22 / Chapter 1.5.3 --- Bioassay --- p.23 / Chapter 1.5.4 --- Colorimetry --- p.25 / Chapter 1.5.5 --- Fluorometry --- p.25 / Chapter 1.5.6 --- Radiochemical techniques --- p.27 / Chapter 1.5.7 --- Radioimmunoassay --- p.29 / Chapter 1.5.8 --- Chromatography --- p.30 / Chapter CHAPTER 2 --- METHODS - DEVELOPMENT OF A CATECHOLAMINE ASSAY & STABILITY STUDIES ON CATECHOLAMINES / Chapter 2.1 --- High performance liquid chromatography and electrochemical detection of catecholamines / Chapter 2.1.1 --- Introduction --- p.38 / Chapter 2.1.2 --- Basic equipment --- p.39 / Chapter 2.1.3 --- Stock aqueous CAT standards --- p.40 / Chapter 2.1.4 --- Mobile phase of HPLC-ECD --- p.40 / Chapter 2.1.5 --- Determination of mobile phase composition and flow rate --- p.41 / Chapter 2.1.6 --- Electrochemical detection --- p.43 / Chapter 2.1.7 --- Linearity and lowest detection limit of HPLC-ECD system --- p.49 / Chapter 2.1.8 --- Maintenance of HPLC-ECD system --- p.54 / Chapter 2.1.9 --- Discussion --- p.56 / Chapter 2.2 --- Sample pre-treatment & stability studies - Human urine / Chapter 2.2.1 --- Pre-treatment --- p.58 / Chapter 2.2.2 --- Analytical performance of the assay --- p.63 / Chapter 2.2.3 --- Stability studies --- p.85 / Chapter 2.2.4 --- Discussion --- p.101 / Chapter 2.2.5 --- Conclusions --- p.108 / Chapter 2.3 --- Sample pre-treatment & stability studies - Rat urine / Chapter 2.3.1 --- Pre-treatment --- p.111 / Chapter 2.3.2 --- Analytical performance of the assay --- p.111 / Chapter 2.3.3 --- Stability studies --- p.119 / Chapter 2.3.4 --- Discussion --- p.131 / Chapter 2.3.5 --- Conclusions --- p.133 / Chapter CHAPTER 3 --- "URINARY CREATININE, SODIUM AND POTASSIUM MEASUREMENTS" / Chapter 3.1 --- Introduction --- p.135 / Chapter 3.2 --- Method / Chapter 3.2.1 --- Urinary creatinine measurement --- p.135 / Chapter 3.2.2 --- Urinary sodium and potassium measurement --- p.136 / Chapter 3.3 --- Results / Chapter 3.3.1 --- Urinary creatinine measurement --- p.136 / Chapter 3.3.2 --- Urinary sodium and potassium measurement --- p.136 / Chapter 3.4 --- Discussion / Chapter 3.4.1 --- Urinary creatinine measurement --- p.136 / Chapter 3.4.2 --- Urinary sodium and potassium measurement --- p.137 / Chapter 3.5 --- Statistics --- p.138 / Chapter 3.6 --- Chemicals --- p.139 / Chapter CHAPTER 4 --- STUDIES ON URINARY EXCRETION OF CATECHOLAMINES IN MAN / Chapter 4.1 --- Population study on the relationships between dietary salt intake and urinary catecholamine output / Chapter 4.1.1 --- Introduction --- p.141 / Chapter 4.1.2 --- Method --- p.142 / Chapter 4.1.3 --- Results --- p.143 / Chapter 4.1.4 --- Discussion --- p.148 / Chapter 4.1.5 --- Conclusions --- p.149 / Chapter 4.2 --- The effect of oral salt loading on urinary catecholamine output / Chapter 4.2.1 --- Introduction --- p.149 / Chapter 4.2.2 --- Methods --- p.150 / Chapter 4.2.3 --- Results --- p.152 / Chapter 4.2.4 --- Discussion --- p.159 / Chapter 4.2.5 --- Conclusions --- p.161 / Chapter 4.3 --- The effects of perindopril on urinary catecholamine outputs / Chapter 4.3.1 --- Introduction --- p.162 / Chapter 4.3.2 --- Methods --- p.165 / Chapter 4.3.3 --- Results --- p.166 / Chapter 4.3.4 --- Discussion --- p.189 / Chapter 4.3.5 --- Conclusions --- p.190 / Chapter CHAPTER 5 --- STUDY ON URINARY EXCRETION OF CATECHOLAMINES AFTER ORAL ADMINISTRATION OF CAPTOPRIL TO RATS / Chapter 5.1 --- Introduction --- p.192 / Chapter 5.2 --- Methods --- p.192 / Chapter 5.3 --- Results --- p.193 / Chapter 5.4 --- Discussion --- p.210 / Chapter 5.5 --- Conclusions --- p.212 / Chapter CHAPTER 6 --- CONCLUSIONS --- p.214 / Chapter CHAPTER 7 --- FUTURE PROSPECTS --- p.216 / PUBLICATIONS TO DATE --- p.218 / ACKNOWLEDGEMENTS --- p.219 / REFERENCES --- p.220