BACKGROUND: The purpose of this study was to determine the role of thromboxane A2 (TXA2) in a conscious, chronically instrumented rat model of pregnancy-induced hypertension (PIH) produced by chronic reductions in uterine perfusion pressure (RUPP). METHODS: Mean arterial pressure (MAP), glomerular filtration rate (GFR), effective renal plasma flow (ERPF) and 24-h urinary excretion of TXB2 (metabolite of TXA2) were determined in normal pregnant rats and RUPP pregnant rats. RESULTS: At day 20 of pregnancy, RUPP rats showed a significantly (P < .05) higher MAP (125 +/- 3 mm Hg v 100 +/- 2 mm Hg) as compared with normal pregnant controls. The elevation in arterial pressure in RUPP group was associated with a marked increase (P < .05) in the urinary concentration of TXB2 compared with normal pregnant group (3663 +/- 488 v 2646 +/- 257 pg/24 h). Baseline GFR (1.74 +/- 0.13 v 2.40 +/- 0.20 mL/min, respectively, P < .05) and ERPF (5.13 +/- 0.44 v 6.44 +/- 0.58 mL/min, respectively) were decreased in RUPP rats relative to pregnant controls. Infusion of a TX receptor antagonist, SQ 29,548 (2 mg/kg bolus plus 2 mg/kg per h infusion) had no significant effect on increased MAP in RUPP pregnant rats. Similarly, ERPF and GFR did not change during acute blockade of TXA2 receptors in this group. CONCLUSION: These findings suggest that enhanced production of TXA2 does not play a major role in mediating the hypertension and renal vasoconstriction produced by chronic RUPP in pregnant rats.
BACKGROUND: The purpose of this study was to determine the role of thromboxane A2 (TXA2) in a conscious, chronically instrumented rat model of pregnancy-induced hypertension (PIH) produced by chronic reductions in uterine perfusion pressure (RUPP). METHODS: Mean arterial pressure (MAP), glomerular filtration rate (GFR), effective renal plasma flow (ERPF) and 24-h urinary excretion of TXB2 (metabolite of TXA2) were determined in normal pregnant rats and RUPP pregnant rats. RESULTS: At day 20 of pregnancy, RUPP rats showed a significantly (P < .05) higher MAP (125 +/- 3 mm Hg v 100 +/- 2 mm Hg) as compared with normal pregnant controls. The elevation in arterial pressure in RUPP group was associated with a marked increase (P < .05) in the urinary concentration of TXB2 compared with normal pregnant group (3663 +/- 488 v 2646 +/- 257 pg/24 h). Baseline GFR (1.74 +/- 0.13 v 2.40 +/- 0.20 mL/min, respectively, P < .05) and ERPF (5.13 +/- 0.44 v 6.44 +/- 0.58 mL/min, respectively) were decreased in RUPP rats relative to pregnant controls. Infusion of a TX receptor antagonist, SQ 29,548 (2 mg/kg bolus plus 2 mg/kg per h infusion) had no significant effect on increased MAP in RUPP pregnant rats. Similarly, ERPF and GFR did not change during acute blockade of TXA2 receptors in this group. CONCLUSION: These findings suggest that enhanced production of TXA2 does not play a major role in mediating the hypertension and renal vasoconstriction produced by chronic RUPP in pregnant rats.
Authors: Florian Herse; Babbette Lamarca; Carl A Hubel; Tea Kaartokallio; A Inkeri Lokki; Eeva Ekholm; Hannele Laivuori; Martin Gauster; Berthold Huppertz; Meryam Sugulle; Michael J Ryan; Sarah Novotny; Justin Brewer; Joon-Keun Park; Michael Kacik; Joachim Hoyer; Stefan Verlohren; Gerd Wallukat; Michael Rothe; Friedrich C Luft; Dominik N Muller; Wolf-Hagen Schunck; Anne C Staff; Ralf Dechend Journal: Circulation Date: 2012-11-15 Impact factor: 29.690
Authors: Adrian C Eddy; John Aaron Howell; Heather Chapman; Erin Taylor; Fakhri Mahdi; Eric M George; Gene L Bidwell Journal: Hypertension Date: 2019-12-02 Impact factor: 10.190
Authors: Babbette D LaMarca; Barbara T Alexander; Jeffery S Gilbert; Michael J Ryan; Mona Sedeek; Sydney R Murphy; Joey P Granger Journal: Gend Med Date: 2008