Uterine and peripheral blood concentrations of vasodilator prostaglandins in conscious pregnant rabbits

Chaudhuri, Gautam; Barone, P.; Lianos, Elias A.; Hurd, Mary; Lele, Amol; Venuto, Rocco C.

doi:10.1016/0002-9378(82)90348-9

Cited by 11 publications

(3 citation statements)

References 15 publications

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“…Prostaglandin E2 (PGE2) reversed the effects of indomethacin and appeared to be the primary endogenous prostaglandin required to ensure full vasoconstrictor responses. Paradoxically, increased blood PGE2 has been described in pregnancy (Chaudhuri et al, 1982).…”

Section: Discussionmentioning

confidence: 99%

Mesenteric arterial function in the rat in pregnancy: role of sympathetic and sensory‐motor perivascular nerves, endothelium, smooth muscle, nitric oxide and prostaglandins

Ralevic

Burnstock

1996

British J Pharmacology

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1 The effects of pregnancy on mesenteric arterial function were examined in constantly perfused (5mlmin-1) mesenteric arterial beds isolated from 21-day pregnant rats. The function of sympathetic and sensory-motor perivascular nerves, endothelium and smooth muscle was examined. The role of nitric oxide and prostaglandins in vasoconstrictor function was tested by use of NG-nitro-L-arginine methyl ester (L-NAME; 100 uM) and indomethacin (10 iM), respectively.2 Electrical field stimulation (EFS; 4-32 Hz, 1 ms, 90 V, 30 s) at basal tone elicited frequency-dependent vasoconstriction which was markedly reduced in preparations from pregnant rats at all frequencies. Vasoconstrictor responses to vasopressin and endothelin were also reduced in pregnancy and there was a trend towards a reduction in maximal responses to noradrenaline (NA). In contrast, there was no difference in vasoconstrictor responses to ATP, 5-hydroxytryptamine (5-HT) or angiotensin II. 3 L-NAME (100 gM) augmented responses to EFS, NA, ATP and vasopressin in control mesenteric arterial preparations. In contrast, L-NAME augmented responses only to EFS in pregnancy, having no significant effect on responses to NA, ATP and vasopressin.4 Indomethacin (10 gM) attenuated responses to NA and vasopressin, but not to EFS, in controls and in pregnancy. Responses to ATP were attenuated by indomethacin in controls but not in pregnancy. 5 Mesenteric preparations from pregnant rats were resistant to having tone raised by continuous perfusion with methoxamine. Despite an approximately 10 fold greater concentration of methoxamine, there was a significantly smaller increase in tone in preparations from pregnant, 34.27+4.8mmHg(n= 11) compared to control, 65.92+5.4mmHg (n= 11), rats. EFS (4-12Hz, 60V, 0.1Ims, 30s) in the presence of guanethidine (5 gM) to block sympathetic neurotransmission elicited frequency-dependent vasodilatation due to activation of sensory-motor nerves. Percentage relaxations were similar in preparations from pregnant and non-pregnant rats. 6 Dose-dependent endothelium-dependent vasodilatations to acetylcholine and ATP were similar in preparations from pregnant and non-pregnant rats. Endothelium-independent vasodilatation to sodium nitroprusside and to calcitonin gene-related peptide were also similar between the two groups. 7 There was no significant difference in the basal perfusion pressure of mesenteric arterial beds from control (21.3 + 1.0 mmHg, n = 24) and pregnant (20.2 + 1.2 mmHg, n = 23) rats. However, a step-wise increase in perfusate flow from 5 to 10, 15, 20 and 24 ml min-' produced smaller increases in perfusion pressure in pregnancy compared to the controls. L-NAME (100,tM) or indomethacin (10jiM) had no significant effect on the relationship between flow and perfusion pressure. 8 The present results show that prejunctional changes are involved in blunted sympathetic vasoconstriction of rat mesenteric arteries in pregnancy. Non-specific postjunctional changes are implicated in the reduced constrictor responses to applied methoxamine, ...

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Section: Discussionmentioning

confidence: 99%

Mesenteric arterial function in the rat in pregnancy: role of sympathetic and sensory‐motor perivascular nerves, endothelium, smooth muscle, nitric oxide and prostaglandins

Ralevic

Burnstock

1996

British J Pharmacology

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“…Changes in MAP were then recorded. This dose of meclofenamate has been shown to inhibit prostaglandin synthesis in pregnant and non-pregnant rabbits (Chaudhuri et al, 1982).…”

Section: Methodsmentioning

confidence: 96%

“…The role of vasodilator prostanoids in modulating basal vascular tone during late pregnancy was also explored in this study as it has been shown that pregnancy results in increased prostaglandin production in women (Bay & Ferris, 1979;Goodman et al, 1982) and in laboratory animals (Gerber et al, 1981;Chaudhuri et al, 1982;Paller et al, 1989). Unlike NO, vasodilator prostanoids do not appear to play an important role in the maintenance of vascular tone in late pregnancy since meclofenamate did not change MAP in pregnant and non-pregnant animals.…”

Section: Iamentioning

confidence: 99%

The role of nitric oxide in the altered vascular reactivity of pregnancy in the rat

Nathan

Cuevas

Chaudhuri

1995

British J Pharmacology

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1 Pregnancy is characterized by a decrease in systemic vascular resistance and a blunting of the angiotensin II (All) pressor response. We studied the role of nitric oxide (NO) and prostanoids in these vascular changes of pregnancy in anaesthesized, ganglion blocked non-pregnant and pregnant rats. 2 Inhibition of NO synthesis with N0-nitro-L-arginine methyl ester (L-NAME) led to an increase in mean arterial pressure (MAP) which was of a significantly greater magnitude in pregnant rats in late gestation than in non-pregnant rats, or rats in mid-gestation. 3 The pressor response to varying doses of All was attenuated during late pregnancy, and this attenuation was partially reversed by L-NAME. 4 The pressor response to varying doses of a vasocontrictor, phenylephrine (PE), was also attenuated in late pregnancy. However, this attenuation was not reversed by L-NAME. 5 Inhibition of prostanoid biosynthesis with meclofenamate did not alter basal MAP, nor the pressor response to varying doses of All or PE in pregnant and non-pregnant animals. 6 It is concluded that (a) increased NO synthesis occurs during late gestation and contributes both to the decrease in systemic vascular resistance, as well as the blunting of the pressor response to All during pregnancy, and (b) prostaglandins are not important in the maintenance of basal vascular tone, or the blunting of the pressor response to All during pregnancy.

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The pregnant rabbit, guinea pig, sheep and rhesus monkey as models in reproductive physiology

Mårtensson

1984

European Journal of Obstetrics & Gynecology and Reproductiv

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Uterine and peripheral blood concentrations of vasodilator prostaglandins in conscious pregnant rabbits

Cited by 11 publications

References 15 publications

Mesenteric arterial function in the rat in pregnancy: role of sympathetic and sensory‐motor perivascular nerves, endothelium, smooth muscle, nitric oxide and prostaglandins

Mesenteric arterial function in the rat in pregnancy: role of sympathetic and sensory‐motor perivascular nerves, endothelium, smooth muscle, nitric oxide and prostaglandins

The role of nitric oxide in the altered vascular reactivity of pregnancy in the rat

The pregnant rabbit, guinea pig, sheep and rhesus monkey as models in reproductive physiology

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