Thesis (Ph. D.)--Cornell University. / Offprint from: Proceedings of the United States National Museum, v. 26, no. 1331.

Thesis (Ph. D.)--Cornell University. / Offprint from: Proceedings of the United States National Museum, v. 26, no. 1331.

Thesis (doctoral)--Ludwig Maximilians-Universität zu München, 1979.

The objective of these experiments was to investigate the effects of various membrane receptor-mediated and receptor-independent vasodilators on the resistance and capacitance vessels of conscious, unrestrained rats by measuring mean arterial pressure (MAP) and mean circulatory filling pressure (MCFP), an index of total body venous tone. ln the first set of experiments the dose-response effects of the directly-acting vasodilators nitroglycerin, sodium nitroprusside and hydralazine were determined in intact rats as well as in rats treated with the ganglionic blocker, hexamethonium. The effects of these drugs were compared with those of the vehicle, normal saline, in control rats. In intact rats, iv infusion of nitroglycerin did not alter MAP while iv infusions of nitroprusside and hydralazine caused dose-dependent decreases in MAP. In intact rats, nitroglycerin and sodium nitroprusside did. not affect MCFP while hydralazine increased MCFP. After treatment with hexamethonium all three drugs decreased MCFP, though the decreases in MCFP caused by hydralazine were not significantly different from the corresponding changes in saline-treated rats. Therefore, sodium nitroprusside and hydralazine but not nitroglycerin were effective arteriolar dilators in intact rats; all three drugs dilated arterioles in ganglionic-blocked rats, ln intact rats, the direct venodilator actions of nitroprusside and nitroglycerin were masked by endogenous sympathetic tone. When sympathetic nerve activity was attenuated, both drugs had venodilatory effects. Hydralazine, on the other hand, hao insignificant venodilatory effects both in the presence and absence of the sympathetic reflexes. In the second set of experiments we determined the dose-response effects of hexamethonium, phentolamine, prazosin and rauwolscine — the latter being non-selective ⍺, ⍺₁-selective, and ⍺₂-selective adrenoceptor antagonists, respectively — in intact rats. Prazosin and rauwolscine were also administered to rats with reflexly increased venous tone induced by the infusion of hydralazine. In intact rats iv infusions of prazosin, phentolamine and rauwolscine all caused dose-dependent decreases in MAP; only rauwolscine reduced MCFP to levels slightly below control. Hexamethonium caused a aecrease in MAP as well as a markea reduction in MCFP. After venous tone was raised by the infusion of hydralazine, both prazosin and rauwolscine dose-dependently decreased MCFP. Therefore, the resistance and capacitance vessels contain both ⍺₁- and ⍺₂-adrenoceptors. in the intact rat, however, the capacitance vessels are somewhat resistant to the effects of postjunctionally acting ⍺-antagonists in contrast to the effects of hexamethonium which acts at the level of the ganglion. / Medicine, Faculty of / Anesthesiology, Pharmacology and Therapeutics, Department of / Graduate

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Saphenous veins are widely used as graft material in coronary artery bypass surgery. Biomechanical testing may help identify veins with the optimum chance of longevity. In this thesis, the author has constructed an experimental apparatus to measure circumferential and axial stress-strain data for such arteries and veins. Three different experimental techniques were used to obtain the dimensions of the vessels during pressure-diameter tests; the traditional method of photographic and direct measurement of the external dimensions along with the assumption of incompressibility to approximate inner dimensions; second the use of intravascular ultrasound to obtain the inner and outer dimensions of the vessels; and third the use of intravascular ultrasound for internal dimensions and photography for the outer dimensions. Three forms of mathematical expression were fitted to the circumferential and axial stress-strain data. The sensitivity of the resulting material parameters was investigated with regard to conversion and reference data variations, and data from repeated experiments, experiments fitting more than one axial strain, and experiments testing the variation in elastic properties were compared. The combination of the ultrasound experimental technique and exponential form of mathematical expression was found to be the most robust. Using this combination, a significant difference between material parameters of pig arteries and human saphenous veins was found . While the data indicate that material parameters of healthy and diseased veins may also differ significantly, the number of healthy veins in this study was not sufficient to be conclusive.

M.S. / Anatomy / The purpose of this paper is to give a description of the hepatic circulation and associated blood vessels of a 6 mm. pig embryo. The early work of His and Hochstetter upon the development of the larger veins and ductus venosus opened the way for later investigation in this field. Minot and Lewis devoted their attention to the study of the minute structure of the hepatic and other sinusoids. Thyng has described a pig embryo of 7.8 mm; Piper, Ingalls, Mall and Jordan have each described human embryos of lengths varying from 4 mm. to 7mm., while Schulte, Huntington and McClure have outlined the development of the venous circulation of the cat. / Poor text quality is due to the onion skin paper the thesis was scanned from.

Thesis (M.A.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains v, 69 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 36-40).

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