Abstract
Background: Administration of high doses of angiotensin II (Ang II) results in natriuretic and diuretic responses that are mediated by increases in renal perfusion pressure (RPP). Elevations in renal interstitial hydrostatic pressure (RIHP) caused by increases in mean arterial pressure (MAP) or RPP are associated with significant increases in urinary sodium excretion (UNaV) and urine flow rate (V). In pregnant rats the renin-angiotensin system (RAS) is activated and basal RIHP is reduced. The exact relationship among MAP, RIHP, UNaV, and V in response to a high pressor dose of Ang II during normal pregnancy is not known. Methods: The objective of this study was to evaluate the relationship between MAP and RIHP, and determine the role of RIHP in the natriuretic and diuretic responses to administration of high dose of Ang II in midterm pregnant (MP) and nonpregnant (NP) Sprague-Dawley (SD) rats. Results: Intravenous infusion of Ang II (200 ng/kg/min) significantly increased MAP (ΔMAP), ΔUNaV, and ΔV in anesthetized MP and NP rats. The ΔMAP, ΔUNaV, and ΔV were 12 ± 2 mm Hg, 27.9 ± 2.7 μEq/min, and 197 ± 23 μL/min for MP rats and were similar (15 ± 3 mm Hg, 34.1 ± 4.3 μEq/min, and 242 ± 34 μL/min, respectively) for NP rats. The RIHP decreased significantly (P < .05) with Ang II infusion in NP (from 6.1 ± 0.2 to 3.9 ± 0.4 mm Hg) but not in MP (from 3.3 ± 0.3 to 4.1 ± 0.4 mm Hg) groups of rats. Acute renal decapsulation eliminated the change in RIHP mediated by high doses of Ang II infusion in the NP group, but did not affect MAP or the natriuretic and diuretic responses to Ang II in either the MP or NP groups of rats. Conclusions: The natriuretic and diuretic responses to high doses of Ang II are not mediated by changes in RIHP in pregnant or nonpregnant rats.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 300-305 |
| Number of pages | 6 |
| Journal | American journal of hypertension |
| Volume | 19 |
| Issue number | 3 |
| DOIs | |
| State | Published - Mar 1 2006 |
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Keywords
- Angiotensin II infusion
- Pregnancy
- Proximal tubular reabsorption
- Renal interstitial hydrostatic pressure
- Sodium excretion
ASJC Scopus subject areas
- Internal Medicine
Cite this
Renal interstitial hydrostatic pressure and natriuretic response to high doses of angiotensin II in pregnant rats. / Yu, Tianzheng; Khraibi, Ali A.
In: American journal of hypertension, Vol. 19, No. 3, 01.03.2006, p. 300-305.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Renal interstitial hydrostatic pressure and natriuretic response to high doses of angiotensin II in pregnant rats
AU - Yu, Tianzheng
AU - Khraibi, Ali A.
PY - 2006/3/1
Y1 - 2006/3/1
N2 - Background: Administration of high doses of angiotensin II (Ang II) results in natriuretic and diuretic responses that are mediated by increases in renal perfusion pressure (RPP). Elevations in renal interstitial hydrostatic pressure (RIHP) caused by increases in mean arterial pressure (MAP) or RPP are associated with significant increases in urinary sodium excretion (UNaV) and urine flow rate (V). In pregnant rats the renin-angiotensin system (RAS) is activated and basal RIHP is reduced. The exact relationship among MAP, RIHP, UNaV, and V in response to a high pressor dose of Ang II during normal pregnancy is not known. Methods: The objective of this study was to evaluate the relationship between MAP and RIHP, and determine the role of RIHP in the natriuretic and diuretic responses to administration of high dose of Ang II in midterm pregnant (MP) and nonpregnant (NP) Sprague-Dawley (SD) rats. Results: Intravenous infusion of Ang II (200 ng/kg/min) significantly increased MAP (ΔMAP), ΔUNaV, and ΔV in anesthetized MP and NP rats. The ΔMAP, ΔUNaV, and ΔV were 12 ± 2 mm Hg, 27.9 ± 2.7 μEq/min, and 197 ± 23 μL/min for MP rats and were similar (15 ± 3 mm Hg, 34.1 ± 4.3 μEq/min, and 242 ± 34 μL/min, respectively) for NP rats. The RIHP decreased significantly (P < .05) with Ang II infusion in NP (from 6.1 ± 0.2 to 3.9 ± 0.4 mm Hg) but not in MP (from 3.3 ± 0.3 to 4.1 ± 0.4 mm Hg) groups of rats. Acute renal decapsulation eliminated the change in RIHP mediated by high doses of Ang II infusion in the NP group, but did not affect MAP or the natriuretic and diuretic responses to Ang II in either the MP or NP groups of rats. Conclusions: The natriuretic and diuretic responses to high doses of Ang II are not mediated by changes in RIHP in pregnant or nonpregnant rats.
AB - Background: Administration of high doses of angiotensin II (Ang II) results in natriuretic and diuretic responses that are mediated by increases in renal perfusion pressure (RPP). Elevations in renal interstitial hydrostatic pressure (RIHP) caused by increases in mean arterial pressure (MAP) or RPP are associated with significant increases in urinary sodium excretion (UNaV) and urine flow rate (V). In pregnant rats the renin-angiotensin system (RAS) is activated and basal RIHP is reduced. The exact relationship among MAP, RIHP, UNaV, and V in response to a high pressor dose of Ang II during normal pregnancy is not known. Methods: The objective of this study was to evaluate the relationship between MAP and RIHP, and determine the role of RIHP in the natriuretic and diuretic responses to administration of high dose of Ang II in midterm pregnant (MP) and nonpregnant (NP) Sprague-Dawley (SD) rats. Results: Intravenous infusion of Ang II (200 ng/kg/min) significantly increased MAP (ΔMAP), ΔUNaV, and ΔV in anesthetized MP and NP rats. The ΔMAP, ΔUNaV, and ΔV were 12 ± 2 mm Hg, 27.9 ± 2.7 μEq/min, and 197 ± 23 μL/min for MP rats and were similar (15 ± 3 mm Hg, 34.1 ± 4.3 μEq/min, and 242 ± 34 μL/min, respectively) for NP rats. The RIHP decreased significantly (P < .05) with Ang II infusion in NP (from 6.1 ± 0.2 to 3.9 ± 0.4 mm Hg) but not in MP (from 3.3 ± 0.3 to 4.1 ± 0.4 mm Hg) groups of rats. Acute renal decapsulation eliminated the change in RIHP mediated by high doses of Ang II infusion in the NP group, but did not affect MAP or the natriuretic and diuretic responses to Ang II in either the MP or NP groups of rats. Conclusions: The natriuretic and diuretic responses to high doses of Ang II are not mediated by changes in RIHP in pregnant or nonpregnant rats.
KW - Angiotensin II infusion
KW - Pregnancy
KW - Proximal tubular reabsorption
KW - Renal interstitial hydrostatic pressure
KW - Sodium excretion
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UR - http://www.scopus.com/inward/citedby.url?scp=32944469925&partnerID=8YFLogxK
U2 - 10.1016/j.amjhyper.2005.09.016
DO - 10.1016/j.amjhyper.2005.09.016
M3 - Article
C2 - 16500518
AN - SCOPUS:32944469925
VL - 19
SP - 300
EP - 305
JO - American Journal of Hypertension
JF - American Journal of Hypertension
SN - 0895-7061
IS - 3
ER -