Thesis (Ph. D.)--Ohio State University, 2003. / Title from first page of PDF file. Document formatted into pages; contains xii, 120 p.; also includes graphics. Includes bibliographical references (p. 110-120).

The present study has established that physiological concentrations of estradiol can modulate stress-induced increases in plasma epinephrine (EPI). In anesthetized female rats, insulin-induced hypoglycemia (0.25 U/kg) increased plasma EPI concentration to a significantly greater extent in 14-day ovariectomized (OVEX) rats compared to sham-operated controls. In 17-estradiol (E2)-replaced OVEX rats, the hypoglycemia-induced rise in plasma EPI was significantly reduced compared to OVEX rats. This suppression was due to both decreased adrenal medullary output and increased clearance of EPI. Adrenal venous EPI concentration was significantly reduced in OVEX+E2 rats, suggesting that EPI secretion from the adrenalmedulla was decreased by E2 replacement. The underlying mechanism(s) of this apparent E2-mediated reduction in secretion could not be established since 1) the expression levels of the biosynthetic enzymes tyrosine hydroxylase and phenylethanolamine N-methyltransferase were not affected in OVEX+E2 rats, suggesting that EPI biosynthesis is similar in these and OVEX rats; and 2) agonist-induced increases in intracellular CaP2+P were identical in isolated adrenal medullary chromaffin cells exposed to E2 (10 nM) or vehicle for 48 hr, suggesting that stimulus secretion coupling is unaffected by E2 treatment. In contrast, plasma clearance of EPI was significantly increased in OVEX+E2 rats. Although 48 hr exposure to E2 had no effect on intracellular signaling in chromaffin cells, acute (3 min) exposure to micromolar concentrations of E2 dose-dependently and reversibly inhibited agonist-induced CaP 2+Ptransients. Consistent with this observation, acute (30 min) infusions of E2 also significantly reduced the insulin-induced increase in plasma EPI in OVEX rats. These data demonstrate that physiological levels of circulating E2 can modulate hypoglycemia-induced increases in plasma EPI. This effect appears to be mediated by the steroids influence on adrenal medullary EPI output and plasma EPI clearance; however the mechanism(s) underlying these E2-mediated modulations remain undetermined. This study has also established that acute exposure to supra-physiological levels of E2 can suppress hypoglycemia-induced increases in plasma EPI, due at least in part to inhibition of stimulus-secretion coupling.

Catecholamines are stress hormones that are produced and released by a rare tumor called pheochromocytoma. This tumor can cause hypertension which if undiagnosed and untreated leads to death. Since good therapy is available, it is important to find the tumor in time. The most common way to diagnose the tumor is measurement of the biochemical markers; catecholamines and their metabolites, methylated catecholamines. After observation that almost all normetanephrine results for women were higher than the upper reference limit and therefore pathological, the accuracy of the present reference intervals was questioned. Therefore new reference intervals for both urinary catecholamines and methylated catecholamines were developed by analysis of 46 samples using HPLC. Creatinine was analysed in acidified urine in order to see if the results became the same as when analysed in non-acidified urine. Urinary catecholamines and methylated catecholamines were analysed using HPLC. Comparison between measurement of creatinine in acidified urine and non-acidified urine with an enzymatic method was performed using Architect ci 8200, Abbott. As suspected, there was a difference between the present and new intervals. Therefore the new intervals will be used for future diagnosis. There was no difference between the two treatments of creatinine samples wherefore it can be measured in both.In conclusion reference intervals determind in this study will be used and it was shown that creatinine can be measured in acidified urine.

Thesis (Ph. D.)--University of Nevada, Reno, 2008. / "December, 2008." Includes bibliographical references. Online version available on the World Wide Web.

No description available.

This thesis has examined the influence of the environment on aspects of the acute stress response in juvenile and pro-larval Acipenser fulvescens.The acute stress response was examined in grouped and isolated juveniles. Catecholamines significantly increased in both treatments one minute post-stress and plasma glucose was significantly higher in isolated as compared to grouped fish one minute post-stress. In the second series of experiments fertilized eggs of A. fulvescens were raised at 9, 12 & 15°C. Chromaffin-like cells were studied using light and electron microscopy techniques. Development of renal tissue was also examined in these treatment groups. Two populations of chromaffin-like cells were identified, one in close association with the proximal tubule of the kidney, and the other in close association with the neural tube. Results suggest this latter population were immature pheochromoblast like-cells. Development of renal tissue followed a predictable pattern that was most rapid in the 15°C treatment.

This thesis has examined the influence of the environment on aspects of the acute stress response in juvenile and pro-larval Acipenser fulvescens.The acute stress response was examined in grouped and isolated juveniles. Catecholamines significantly increased in both treatments one minute post-stress and plasma glucose was significantly higher in isolated as compared to grouped fish one minute post-stress. In the second series of experiments fertilized eggs of A. fulvescens were raised at 9, 12 & 15°C. Chromaffin-like cells were studied using light and electron microscopy techniques. Development of renal tissue was also examined in these treatment groups. Two populations of chromaffin-like cells were identified, one in close association with the proximal tubule of the kidney, and the other in close association with the neural tube. Results suggest this latter population were immature pheochromoblast like-cells. Development of renal tissue followed a predictable pattern that was most rapid in the 15°C treatment.

Thesis (Ph.D)--Murdoch University, 2007. / Thesis submitted to the Division of Health Sciences. Includes bibliographical references (leaves 232-267).

Thesis (Ph. D.)--University of Virginia, 1997. / Spine title: c-Src-Associated PTPase. Includes bibliographical references (169-197). Also available online through Digital Dissertations.

Thesis (doctoral)--Lund University, 1997. / Added t.p. with thesis statement inserted.