Pregnancy restores the renal vasodilator response to glycine in Dahl salt-sensitive rats.
To determine if pregnancy alters the impaired renal vasodilator responses in hypertensive Dahl salt-sensitive (Dahl S) rats, we measured glomerular filtration rate and effective renal plasma flow and calculated renal vascular resistance before, during, and after renal vasodilation with glycine (0.17 mmol/kg per minute IV). Conscious, midterm (day 11 to 14) pregnant and age-matched virgin Dahl S and Dahl salt-resistant (Dahl R) rats were fed an 8% NaCl diet for 4 weeks (n = 6 per group). Mean arterial pressure was elevated (P < .05) in Dahl S compared with Dahl R rats, with no significant difference between pregnant and virgin animals in either group. Pregnancy resulted in significant increases in plasma volume, baseline glomerular filtration rate, and renal plasma flow and a significant decrease in renal vascular resistance. The glycine-induced increase in filtration rate in virgin Dahl S rats (27 +/- 4%) was less (P < or = .01) than pregnant Dahl S (60 +/- 4%) and either group of Dahl R (virgin, 43 +/- 3%; pregnant, 45 +/- 5%) rats. Similarly, the 21 +/- 4% increase in renal plasma flow in virgin Dahl S rats was less (P < or = .01) than the pregnant Dahl S (45 +/- 4%) and either pregnant (45 +/- 5%) or virgin (45 +/- 5%) Dahl R rats. Glycine decreased renal vascular resistance only 12 +/- 2% in the virgin Dahl S compared with 31 +/- 3% in the pregnant Dahl S rats and 30 +/- 4% and 28 +/- 3% in pregnant and virgin Dahl R rats.(ABSTRACT TRUNCATED AT 250 WORDS)
Whitescarver
S A
SA
Department of Physiology, Ohio State University, Columbus 43210-1218.
Heesch
C M
CM
D000704:Analysis of Variance; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001810:Blood Volume / Q000187:drug effects; D004195:Disease Models, Animal; D005260:Female; D005919:Glomerular Filtration Rate / Q000187:drug effects; D005998:Glycine / Q000494:pharmacology*; D006973:Hypertension / Q000503:physiopathology*; D007668:Kidney / Q000187:drug effects*; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000503:physiopathology*; D051381:Rats; D011919:Rats, Inbred Strains; D012079:Renal Circulation / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects*
D005998:Glycine