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dc.contributor.authorRouch, Alexander John
dc.date.accessioned2021-03-31T19:31:16Z
dc.date.available2021-03-31T19:31:16Z
dc.date.issued1989-06
dc.identifier.urien
dc.identifier.urihttp://hdl.handle.net/10675.2/623950
dc.description.abstractFluoride flux (JF) was measured in the isolated perfused rabbit cortical collecting duct (CCD) to determine some of the basic physiological characteristics of JF in this segment. Also, the effect of fluoride on hydraulic conductivity (Lp) in the CCD was assessed. Fluoride can increase cyclic AMP levels in a variety of tissues and the vasopressin-induced increase in Lp in the CCD is a cyclic AMPdependent event. To determine if fluoride would increase Lp. Lp was compared among 3 conditions: 1) control, (no fluoride or vasopressin); 2) with 1 or 5 mM .fluoride in the bath; and 3) with 25 J.LU/ml vasopressin in the bath. The Lp in condition 1 was not different from that in 2 (8.6 ± 1.8 vs 5.0 ± 2.7 cm/sec/atm X I0-7, respectively, n=5) (Data expressed as mean ± SE). Lp in condition 3 (112 ± 7.4 cm/sec/atm X 10-7) was significantly higher than that in 1 and 2 (p<.001). The effect of luminal-fluid pH on JF was assessed. In one set of experiments (n=7), JF determined with a pH of 6.1 was significantly higher than that with a pH of 7.4 (.027 ± .007 vs .008 ± .002 pmole/min/mm, respectively; p<.01). In another set (n=5), JF with a pH of 5.0 was significantly higher than that with a pH of 6.1 (.040 ± .004 vs .018 ± .003 pmole/min/mm, respectively; p<.01). Bath pH was always 7.4. Osmotically-induced, lumen-to-bath fluid flux (Jv) did not affect JF. A 40o/o reduction in the trans epithelial fluoride concentration gradient did not affect JF. The effects of acetazolamide and the disulfonic stilbene DIDS on JF were determined separately by measuring JF in the absence and presence of each agent. Neither of these agents significantly affected JF, although JF was reduced consistently with acetazolamide. JF measured with bicarbonate-buffered solutions (.025 ± .003 pmole/min/ID.Iil, n=30) was significantly higher than that with HEPES-buffered solutions (.012 ± .003 pmole/min/mm, n=16) (p<.02). Transepithelial voltages which ranged from +10 to - 104 mV did not affect JF. It was concluded that: 1) fluoride did not affect Lp: 2) Jv did not affect JF: 3) pH gradients affected JF: 4) acetazolamide and DIDS did not affect JF: 5) JF was affected by the buffer of the solution: and 6) the CCD permeability for fluoride is relatively low.en_US
dc.language.isoen_USen_US
dc.publisherAugusta Universityen_US
dc.rightsCopyright protected. Unauthorized reproduction or use beyond the exceptions granted by the Fair Use clause of U.S. Copyright law may violate federal law.en_US
dc.subjectFlurideen_US
dc.subjectFluoride Fluxen_US
dc.subjectDuct Voltageen_US
dc.titleCharacteristics of fluoride flux and the absence of a vasopressin-like effect by fluoride in the isolated perfused rabbit cortical collecting ducten_US
dc.typeDissertationen_US
dc.contributor.departmentDepartment of Physiology and Endocrinologyen_US
dc.description.advisorWhitford, Gary M.
dc.description.committeeGinsburg, J.M.
dc.description.committeeBond, G.C.
dc.description.committeePashley, D.H.
dc.description.degreeDoctor of Philosophyen_US
dc.embargoen
refterms.dateFOA2021-03-31T19:31:16Z


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