Hypertension produced by reductions in uterine perfusion in the pregnant rat: role of interleukin 6.
The purpose of this study was to determine the role of interleukin (IL) 6 in mediating the increase in arterial pressure (AP) in response to chronic reductions in uterine perfusion pressure (RUPP) in pregnant rats. AP was higher in RUPP rats (138+/-1 mm Hg) than in normal pregnant (NP) rats (104+/-1 mm Hg). Serum IL-6 levels in the RUPP rats were 104.5+/-28.6 pg/mL as compared with 36.6+/-7.4 pg/mL in NP rats. To determine the long-term effects of a 2- to 3-fold elevation in plasma IL-6 on renal function and AP in pregnant rats, we infused IL-6 for 5 days (2.5 ng/day) in NP rats starting at day 14 of gestation. Five days later, serum IL-6 levels were 55.5+/-6.5 pg/mL in the control NP rats and 157.0+/-36.1 pg/mL in the IL-6-treated NP rats. AP was higher in the IL-6-treated NP rats (115+/-3 mm Hg) as compared with NP controls (101+/-1 mm Hg) at day 19 of gestation. Renal plasma flow and GFR were lower in the IL-6-treated NP rats than in the NP group. IL-6 increased plasma renin activity but did not affect endothelin in IL-6-treated NP rats. In contrast to the NP rats, IL-6 had no effect on AP or renal hemodynamics in virgin rats. In summary, these data indicate that plasma IL-6 is elevated in response to chronic reductions in uterine perfusion in pregnant rats and that a comparable elevation in plasma IL-6 increases AP and reduces renal function in pregnant rats.
Gadonski
Giovani
G
Department of Physiology and Obstetrics, Center for Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, Jackson, Miss. 39216-4505, USA.
LaMarca
B Babbette D
BB
Sullivan
Elizabeth
E
Bennett
William
W
Chandler
Derrick
D
Granger
Joey P
JP
D000818:Animals; D001012:Aorta, Abdominal; D001794:Blood Pressure; D019332:Endothelin-1 / Q000378:metabolism; D005260:Female; D006439:Hemodynamics; D006973:Hypertension / Q000209:etiology*; D015850:Interleukin-6 / Q000097:blood*; D007668:Kidney / Q000378:metabolism / Q000503:physiopathology; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000209:etiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012039:Regional Blood Flow; D012079:Renal Circulation; D012083:Renin / Q000097:blood; D013525:Surgical Instruments; D014599:Uterus / Q000098:blood supply*
D019332:Endothelin-1; D015850:Interleukin-6; D012083:Renin