Increased acetylcholine-induced vasodilation in pregnant rats: A role for gap junctional communication

Maria Fernanda Villela Dantas, Marcia Urban, David C. Spray, Maria Helena Catelli De Carvalho, Rita De Cassia Aleixo Tostes Passaglia

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

We have tested the hypothesis that increased gap junctional communication contributes to the augmented endothelium-dependent vasodilation in pregnancy. Contractile force and connexin43 expression were measured in aortic rings from nonpregnant and pregnant rats. Norepinephrine-constricted aortas from pregnant rats were more sensitive to acetylcholine, but not to sodium nitroprusside, compared with those from nonpregnant rats. Vessels from pregnant rats, constricted either with 45 mmol/L KCl or with norepinephrine± 10-4 mol/L N(G)-monomethyl-L-arginine (L-NMMA), an inhibitor of nitric oxide synthase, also exhibited greater relaxation to acetylcholine. Heptanol, an uncoupler of gap junctional communication, inhibited acetylcholine responses in norepinephrine-constricted aortas from nonpregnant rats but greatly impaired acetylcholine relaxation in aortas from pregnant rats. Heptanol also inhibited in both groups acetylcholine responses in vessels constricted with KCl, only minimally affected acetylcholine relaxation in arteries constricted with norepinephrine+L-NMMA, and did not change sodium nitroprusside-induced relaxation. Tetraethylammonium chloride induced greater contractions in control aortas compared with aortas from pregnant rats. Increased connexin43 mRNA levels were found in the uterus and in the roesenteric, uterine, and thoracic aortic arteries, but not in the heart and brain, from pregnant rats. These results suggest that increased gap junctional communication, possibly due to increased gap junction protein expression, may facilitate the effects of endothelium-derived relaxing factors, contributing to the augmented endothelium-dependent relaxation in arteries from pregnant rats.

Original languageEnglish (US)
Pages (from-to)937-942
Number of pages6
JournalHypertension
Volume34
Issue number4 II
StatePublished - Oct 1999

Fingerprint

Vasodilation
Acetylcholine
Communication
Aorta
Norepinephrine
Heptanol
omega-N-Methylarginine
Connexin 43
Nitroprusside
Endothelium
Thoracic Arteries
Arteries
Endothelium-Dependent Relaxing Factors
Connexins
Tetraethylammonium
Nitric Oxide Synthase
Uterus
Arginine
Pregnancy
Messenger RNA

Keywords

  • Endothelium-derived factor
  • Gap junctions
  • Nitric oxide
  • Preeclampsia
  • Rats

ASJC Scopus subject areas

  • Internal Medicine

Cite this

Villela Dantas, M. F., Urban, M., Spray, D. C., Catelli De Carvalho, M. H., & Tostes Passaglia, R. D. C. A. (1999). Increased acetylcholine-induced vasodilation in pregnant rats: A role for gap junctional communication. Hypertension, 34(4 II), 937-942.

Increased acetylcholine-induced vasodilation in pregnant rats : A role for gap junctional communication. / Villela Dantas, Maria Fernanda; Urban, Marcia; Spray, David C.; Catelli De Carvalho, Maria Helena; Tostes Passaglia, Rita De Cassia Aleixo.

In: Hypertension, Vol. 34, No. 4 II, 10.1999, p. 937-942.

Research output: Contribution to journalArticle

Villela Dantas, MF, Urban, M, Spray, DC, Catelli De Carvalho, MH & Tostes Passaglia, RDCA 1999, 'Increased acetylcholine-induced vasodilation in pregnant rats: A role for gap junctional communication', Hypertension, vol. 34, no. 4 II, pp. 937-942.
Villela Dantas MF, Urban M, Spray DC, Catelli De Carvalho MH, Tostes Passaglia RDCA. Increased acetylcholine-induced vasodilation in pregnant rats: A role for gap junctional communication. Hypertension. 1999 Oct;34(4 II):937-942.
Villela Dantas, Maria Fernanda ; Urban, Marcia ; Spray, David C. ; Catelli De Carvalho, Maria Helena ; Tostes Passaglia, Rita De Cassia Aleixo. / Increased acetylcholine-induced vasodilation in pregnant rats : A role for gap junctional communication. In: Hypertension. 1999 ; Vol. 34, No. 4 II. pp. 937-942.
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