Abstract
Objective: The study examined the effects of salt-induced hypertension on vascular contractile responses during pregnancy and the mechanisms of the effects. Methods: Aortic rings from pregnant Wistar rats, fed for 6 weeks on diets containing 0.3% (control) and 8.0% (test) sodium chloride were contracted by phenylephrine, 5-hydroxytryptamine, and potassium chloride, in the presence and absence of either endothelium or 10-6 M indomethacin. Contractile responses to calcium chloride were also assessed. Results: High salt intake increased the systolic blood pressure of the rats. Rings from the high-salt-fed rats showed enhanced reactivity to phenylephrine, but not to potassium chloride and 5-hydroxytryptamine. Indomethacin treatment decreased the contractions of rings from the test rats to phenylephrine, but did not significantly affect the responses of rings from the control rats. Removal of endothelium resulted in similar increase in the contractile responses of rings from both groups of rats to phenylephrine but had no effect on responses to 5-hydroxytryptamine and potassium chloride. Rings from hypertensive rats showed significantly increased maximal contractions to calcium chloride when pretreated with phenylephrine but not potassium chloride. Contractile responses to phenylephrine in calcium-free medium were similar in both groups of rats. Conclusions: The results suggest that the enhanced contractions of aortic rings from pregnant rats with salt-induced hypertension are related to alterations in adrenergic mechanisms, and are mediated by vasoconstrictor prostaglandin and enhanced calcium influx through a phenylephrine-activated receptor operated calcium entry pathway. The capacity to produce endothelium-dependent relaxation appears unaltered in this form of hypertension in pregnancy. Objective: The aim of the study was to elucidate the biochemical and structural basis of the modifications in endothelial functions recently described in pregnancy-induced hypertension (PIH). Methods: Umbilical cords were obtained from 6 healthy pregnant women and 6 women affected by PIH. Endothelial cells were prepared by an adaptation of the method of Jaffe et al. The fluidity of the cellular membrane was assayed by the fluorescent probe l-(4-trimethylaminophenyl)-6-phenyl-l,3,5-hexatriene (TMA-DPH). The fluid-phase endocytosis of the cells was studied by the measurement of the probe fraction internalized by endocytosis as described by Illinger. The morphological study was performed by transmission electron microscopy (TEM). Results: In comparison with endothelial cells from controls the cells from PIH women showed: (i) a significant decrease in the anisotropy values of TMA-DPH (P
| Original language | English |
|---|---|
| Pages (from-to) | 227-234 |
| Number of pages | 8 |
| Journal | Hypertension in Pregnancy |
| Volume | 14 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 1995 |
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Keywords
- Electron microscopy study
- Endocytosis
- Endothelial cell
- Mechanisms
- Membrane fluidity
- Pregnancy
- Pregnancy-induced hypertension
- Salt-induced hypertension
ASJC Scopus subject areas
- Obstetrics and Gynaecology
- Internal Medicine
Cite this
Pregnancy-induced hypertension is associated with an activation of endothelial cells. / Cester, Nelvio; Romanini, Carlo; Pugnaloni, Armanda; Biagini, Graziella; Rizzoli, C.; Salvolini, Eleonora; Staffolani, Roberto; Mazzanti, Laura; Rabini, Rosa Anna.
In: Hypertension in Pregnancy, Vol. 14, No. 2, 1995, p. 227-234.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Pregnancy-induced hypertension is associated with an activation of endothelial cells
AU - Cester, Nelvio
AU - Romanini, Carlo
AU - Pugnaloni, Armanda
AU - Biagini, Graziella
AU - Rizzoli, C.
AU - Salvolini, Eleonora
AU - Staffolani, Roberto
AU - Mazzanti, Laura
AU - Rabini, Rosa Anna
PY - 1995
Y1 - 1995
N2 - Objective: The study examined the effects of salt-induced hypertension on vascular contractile responses during pregnancy and the mechanisms of the effects. Methods: Aortic rings from pregnant Wistar rats, fed for 6 weeks on diets containing 0.3% (control) and 8.0% (test) sodium chloride were contracted by phenylephrine, 5-hydroxytryptamine, and potassium chloride, in the presence and absence of either endothelium or 10-6 M indomethacin. Contractile responses to calcium chloride were also assessed. Results: High salt intake increased the systolic blood pressure of the rats. Rings from the high-salt-fed rats showed enhanced reactivity to phenylephrine, but not to potassium chloride and 5-hydroxytryptamine. Indomethacin treatment decreased the contractions of rings from the test rats to phenylephrine, but did not significantly affect the responses of rings from the control rats. Removal of endothelium resulted in similar increase in the contractile responses of rings from both groups of rats to phenylephrine but had no effect on responses to 5-hydroxytryptamine and potassium chloride. Rings from hypertensive rats showed significantly increased maximal contractions to calcium chloride when pretreated with phenylephrine but not potassium chloride. Contractile responses to phenylephrine in calcium-free medium were similar in both groups of rats. Conclusions: The results suggest that the enhanced contractions of aortic rings from pregnant rats with salt-induced hypertension are related to alterations in adrenergic mechanisms, and are mediated by vasoconstrictor prostaglandin and enhanced calcium influx through a phenylephrine-activated receptor operated calcium entry pathway. The capacity to produce endothelium-dependent relaxation appears unaltered in this form of hypertension in pregnancy. Objective: The aim of the study was to elucidate the biochemical and structural basis of the modifications in endothelial functions recently described in pregnancy-induced hypertension (PIH). Methods: Umbilical cords were obtained from 6 healthy pregnant women and 6 women affected by PIH. Endothelial cells were prepared by an adaptation of the method of Jaffe et al. The fluidity of the cellular membrane was assayed by the fluorescent probe l-(4-trimethylaminophenyl)-6-phenyl-l,3,5-hexatriene (TMA-DPH). The fluid-phase endocytosis of the cells was studied by the measurement of the probe fraction internalized by endocytosis as described by Illinger. The morphological study was performed by transmission electron microscopy (TEM). Results: In comparison with endothelial cells from controls the cells from PIH women showed: (i) a significant decrease in the anisotropy values of TMA-DPH (P
AB - Objective: The study examined the effects of salt-induced hypertension on vascular contractile responses during pregnancy and the mechanisms of the effects. Methods: Aortic rings from pregnant Wistar rats, fed for 6 weeks on diets containing 0.3% (control) and 8.0% (test) sodium chloride were contracted by phenylephrine, 5-hydroxytryptamine, and potassium chloride, in the presence and absence of either endothelium or 10-6 M indomethacin. Contractile responses to calcium chloride were also assessed. Results: High salt intake increased the systolic blood pressure of the rats. Rings from the high-salt-fed rats showed enhanced reactivity to phenylephrine, but not to potassium chloride and 5-hydroxytryptamine. Indomethacin treatment decreased the contractions of rings from the test rats to phenylephrine, but did not significantly affect the responses of rings from the control rats. Removal of endothelium resulted in similar increase in the contractile responses of rings from both groups of rats to phenylephrine but had no effect on responses to 5-hydroxytryptamine and potassium chloride. Rings from hypertensive rats showed significantly increased maximal contractions to calcium chloride when pretreated with phenylephrine but not potassium chloride. Contractile responses to phenylephrine in calcium-free medium were similar in both groups of rats. Conclusions: The results suggest that the enhanced contractions of aortic rings from pregnant rats with salt-induced hypertension are related to alterations in adrenergic mechanisms, and are mediated by vasoconstrictor prostaglandin and enhanced calcium influx through a phenylephrine-activated receptor operated calcium entry pathway. The capacity to produce endothelium-dependent relaxation appears unaltered in this form of hypertension in pregnancy. Objective: The aim of the study was to elucidate the biochemical and structural basis of the modifications in endothelial functions recently described in pregnancy-induced hypertension (PIH). Methods: Umbilical cords were obtained from 6 healthy pregnant women and 6 women affected by PIH. Endothelial cells were prepared by an adaptation of the method of Jaffe et al. The fluidity of the cellular membrane was assayed by the fluorescent probe l-(4-trimethylaminophenyl)-6-phenyl-l,3,5-hexatriene (TMA-DPH). The fluid-phase endocytosis of the cells was studied by the measurement of the probe fraction internalized by endocytosis as described by Illinger. The morphological study was performed by transmission electron microscopy (TEM). Results: In comparison with endothelial cells from controls the cells from PIH women showed: (i) a significant decrease in the anisotropy values of TMA-DPH (P
KW - Electron microscopy study
KW - Endocytosis
KW - Endothelial cell
KW - Mechanisms
KW - Membrane fluidity
KW - Pregnancy
KW - Pregnancy-induced hypertension
KW - Salt-induced hypertension
UR - http://www.scopus.com/inward/record.url?scp=0029017268&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0029017268&partnerID=8YFLogxK
U2 - 10.3109/10641959509009583
DO - 10.3109/10641959509009583
M3 - Article
AN - SCOPUS:0029017268
VL - 14
SP - 227
EP - 234
JO - Hypertension in Pregnancy
JF - Hypertension in Pregnancy
SN - 1064-1955
IS - 2
ER -