This thesis work presents the analysis of Oscillometric blood pressure pulse waveform under different pressure points (Systolic, Mean Arterial, and Diastolic Pressures). Pulse waveforms' characteristics were determined from the waveforms at three different pressures and are compared for subjects at three different age groups. Estimation of blood pressure using a morphology based approach was done by using the change of pulse waveform characteristics at different pressure points. Pulse waveforms' characteristics that were obtained from pulse waveforms are utilized to estimate SBP, MAP, and DBP. The estimates obtained with pulse morphology based technique are compared with a BP measurement device and Maximum Amplitude Algorithm. Maximum slope of the pulse was also used for blood pressure estimation. The effect of movement and breathing on proposed method and MAA were compared and it was observed that breathing artifacts affect less the proposed method.

The nucleus tractus solitarii (NTS) is the primary integrative center for baroreflex. NTS not only integrates convergent information from peripheral baroreceptors and higher blood pressure (BP) control centers in CNS but itself is the site of substantial modulation. Our previous studies demonstrated that microinjection of nicotine into the NTS decrease BP and heart rate (HR), which indicates nicotine plays cardiovascular modulatory role in the NTS. However, the mechanisms how nicotine modulate cardiovascular functions in the NTS remained unclear. The aim of this study was to investigate the molecular mechanisms of nicotine-induced depressor and bradycardic effects in the NTS. Male anesthetized Wistar-Kyoto rats, with or without intra-NTS nitric oxide synthase (NOS) inhibitors or ionotropic glutamate receptor inhibitors pretreatment, received intra-NTS nicotine microinjection. BP and HR were monitored. Besides, NTS with/without nicotine microinjection were dissected and subjected to immunoblotting and nitric oxide (NO) analysis. Our results demonstrated that NO analysis study revealed intra-NTS NO production elevated after nicotine microinjection. The depressor and bradycardic effects of intra-NTS nicotine microinjection were diminished by pretreatment of calmodulin inhibitor (W7, 0.33 nmol), non-specific NOS inhibitor (L-NAME, 33 nmol) and eNOS specific inhibitor (L-NIO, 6 nmol). The cardiovascular effects of nicotine were also attenuated by NMDA receptor inhibitor (MK801, 1 nmol), not by non-NMDA receptor inhibitor (NBQX, 10 pmol). Immunoblotting and immunohistochemical studies did not revealed nicotine induced eNOSS1177 phosphorylation in NTS. Using MEK inhibitor, PD98059, and nNOS specific inhibitor,Vinyl-L-NIO and 7-NI, there were no effect on the depressor and bradycardic effects of intra-NTS nicotine microinjection, and the phosphorylation of AktT473 was not induced by nicotine. Therefore, our results indicate that nicotine-induced depressor and bradycardic responses maybe mediated through activating eNOS by calmodulin and stimulating glutamate release in the NTS.

published_or_final_version / Public Health / Master / Master of Public Health

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Heme is essential for numerous enzymes involved in the regulation of vascular tone; it is an integral component of nitric oxide synthase and soluble guanylyl cyclase, and is the substrate for heme oxygenase, enzymes critical for vasodilation. Inhibition of heme synthesis is anticipated to result in a deficiency in these hemoproteins, causing disturbances in the tissue’s ability to regulate vascular tone. Hypertension is frequently associated with the morbidity of both porphyria and lead poisoning, two conditions wherein heme biosynthesis is disrupted. The hypothesis tested was, that extended pharmacological inhibition of heme synthesis disrupts normal vascular control and induces hypertension. Rats were treated with SA, a heme synthesis inhibitor, for two weeks; this depleted heme stores of the liver, kidney, spleen and vasculature by up to 62.2%. A significant decrease in hematocrit, hemoglobin, urine nitrate levels, NOS activity and sGC activity were also produced, indicating compromised hemoprotein synthesis and function. Ex vivo studies of blood vessels revealed blunted sensitivity to nitric oxide donors. Lastly, SA treatment produced a significant increase in left ventricular mass, which is indicative of altered cardiac output and blood pressure elevation. Next, telemetry devices were used to determine in vivo blood pressure and salt-sensitivity of blood pressure of rats treated with SA for 33 days. Hemodynamic changes were minimal, yet there was a mild decrease in pressure over two weeks of SA treatment alone. The change from low to high salt diet in SA rats showed no difference compared to control rats. A small increase was observed in 3 mg/kg L-NAME plus high salt compared to high salt alone, while there was no change at this dose in control animals. Heme tissue and blood content was depleted by up to 47%, but was less than two-week experiments. An increase in kidney medulla NOS activity by 19% was observed in vitro compared to controls. Initial two-week experiments were consistent with the hypothesis above, as heme depletion impaired in vivo activity of NOS and sGC and altered vasodilator function. Nevertheless, in vivo results did not support the hypothesis as hypertension and salt-sensitivity of blood pressure were not observed. / Thesis (Master, Pharmacology & Toxicology) -- Queen's University, 2008-06-19 12:32:08.686

No description available.

This thesis work presents the analysis of Oscillometric blood pressure pulse waveform under different pressure points (Systolic, Mean Arterial, and Diastolic Pressures). Pulse waveforms' characteristics were determined from the waveforms at three different pressures and are compared for subjects at three different age groups. Estimation of blood pressure using a morphology based approach was done by using the change of pulse waveform characteristics at different pressure points. Pulse waveforms' characteristics that were obtained from pulse waveforms are utilized to estimate SBP, MAP, and DBP. The estimates obtained with pulse morphology based technique are compared with a BP measurement device and Maximum Amplitude Algorithm. Maximum slope of the pulse was also used for blood pressure estimation. The effect of movement and breathing on proposed method and MAA were compared and it was observed that breathing artifacts affect less the proposed method.

Thesis (Ph. D.)--State University of New York at Binghamton, Decker School of Nursing, 2007. / Includes bibliographical references.