TY - JOUR
T1 - Pregnancy influence on the vascular interactions between nitric oxide and other endothelium-derived mediators in rat kidney
AU - Bobadilla, Rosa A.
AU - Anguiano, Liliana
AU - Pérez-Alvarez, Victor
AU - López Sanchez, Pedro
PY - 2003/1/1
Y1 - 2003/1/1
N2 - Peripheral vascular resistance and sensitivity to circulating pressor and vasoconstrictor agents are blunted during pregnancy. This has been mainly attributed to an increased production of endothelium-derived mediators. The objective of this work was to evaluate if pregnancy changes the relative participation of nitric oxide (NO) and prostaglandins (PG) in respect to the modulation of the increases in renal perfusion pressure induced by phenylephrine (Phe). Dose-response curves were made with gradually increasing doses of Phe using an isolated kidney preparation in the presence of a NO synthase (NOS) inhibitor (L-NAME, 1 μM), a PG-synthesis inhibitor (indomethacin, 1 μM), both, or neither. Also, renal cyclooxygenase (COX-1 and COX-2) and endothelial NOS (eNOS) expression was determined using PCR. The experiments were done in kidneys from nonpregnant and pregnant rats. Our results showed that the relative participation of renal vasoactive mediators seems to change during pregnancy. We found the presence of a COX-1-dependent vasoconstrictor in the middle of pregnancy that was not found in nonpregnant rats. Our results also suggest that there is increased participation of another renal vasodilator substance, the effect of which is observed when NO or PG synthesis is inhibited during late pregnancy. In addition, an apparent interaction between renal eNOS and COX-1 expression was observed: eNOS expression was diminished, while COX-1 was increased during the 2nd week of pregnancy. In contrast, in kidneys from the 3rd week of pregnancy, the expression of these two enzymes was similar.
AB - Peripheral vascular resistance and sensitivity to circulating pressor and vasoconstrictor agents are blunted during pregnancy. This has been mainly attributed to an increased production of endothelium-derived mediators. The objective of this work was to evaluate if pregnancy changes the relative participation of nitric oxide (NO) and prostaglandins (PG) in respect to the modulation of the increases in renal perfusion pressure induced by phenylephrine (Phe). Dose-response curves were made with gradually increasing doses of Phe using an isolated kidney preparation in the presence of a NO synthase (NOS) inhibitor (L-NAME, 1 μM), a PG-synthesis inhibitor (indomethacin, 1 μM), both, or neither. Also, renal cyclooxygenase (COX-1 and COX-2) and endothelial NOS (eNOS) expression was determined using PCR. The experiments were done in kidneys from nonpregnant and pregnant rats. Our results showed that the relative participation of renal vasoactive mediators seems to change during pregnancy. We found the presence of a COX-1-dependent vasoconstrictor in the middle of pregnancy that was not found in nonpregnant rats. Our results also suggest that there is increased participation of another renal vasodilator substance, the effect of which is observed when NO or PG synthesis is inhibited during late pregnancy. In addition, an apparent interaction between renal eNOS and COX-1 expression was observed: eNOS expression was diminished, while COX-1 was increased during the 2nd week of pregnancy. In contrast, in kidneys from the 3rd week of pregnancy, the expression of these two enzymes was similar.
KW - EDHF
KW - Kidney
KW - Nitric oxide
KW - Pregnancy
KW - Prostaglandins
UR - http://www.scopus.com/inward/record.url?scp=0037252990&partnerID=8YFLogxK
U2 - 10.1139/y02-168
DO - 10.1139/y02-168
M3 - Artículo
SN - 0008-4212
VL - 81
SP - 1
EP - 8
JO - Canadian Journal of Physiology and Pharmacology
JF - Canadian Journal of Physiology and Pharmacology
IS - 1
ER -