Permeability of the Foetal Guinea-Pig Placenta to Arginine-Vasopressin

Forsling, Mary L.; Fenton, Enid

doi:10.1677/joe.0.0720409

Cited by 5 publications

(3 citation statements)

References 4 publications

(5 reference statements)

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“…Plasma concentrations in the pig fetus were consistently higher than those in the sow, thereby indicating that they were not passively derived from the maternal circulation. These observations were consistent with the findings in other species that the placenta is effectively impermeable to vasopressin (Forsling & Fenton, 1977). Similar concentrations of arginine vasopressin with no upward trend during gestation are found in the unstressed fetal sheep, (Stark, Daniel, Husain, James & Van de Weile, 1979;Drummond et al 1980;Rose et al 1981).…”

Section: Discussionsupporting

confidence: 90%

Effect of Haemorrhage on Plasma Lysine Vasopressin and the Cardiovascular Responses to Vasopressin in the Pig Fetus

et al. 1986

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SUMMARYThe effect of haemorrhage on plasma lysine vasopressin concentrations and the cardiovascular effects of intravenous injections of synthetic lysine vasopressin were studied in twenty-four chronically catheterized pig fetuses aged between 81 and 114 d gestation (term = 114 ± 1 d).Removal of 15-20% of the estimated blood volume reduced mean arterial blood pressure and elevated plasma vasopressin concentrations above the mean basal value of 2-2 + 0 3 ,uu./ml. The vasopressin concentration in plasma of fetuses younger than 104 d was insignificantly affected at 30 and 60 min after the bleed, whereas the corresponding values in older fetuses were raised by 127±72,uu./ml (d.f. = 7) and 16 0+ 60 uu./ml (d.f. = 7) respectively. The pituitary concentration of vasopressin was also greater towards the end of gestation. Plasma osmolality was unaffected by fetal blood loss. Maternal concentrations of vasopressin did not change from the basal values of [ 00± 01 ,uu./ml (d.f. = 16). Injection of vasopressin raised fetal blood pressure and decreased heart rate. These results demonstrate that lysine vasopressin is present in the circulation of the pig fetus at 81 d (0-72 gestation), and that near term fetuses respond to haemorrhage more rapidly, and to a greater degree than younger fetuses.

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Section: Discussionsupporting

confidence: 90%

Effect of Haemorrhage on Plasma Lysine Vasopressin and the Cardiovascular Responses to Vasopressin in the Pig Fetus

et al. 1986

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“…These data suggest that the placenta is responsible for 90% of fetal AVP clearance. In contrast, Forsling and Fenton [4], in perfusing guinea-pig pla centas with varying amounts of AVP, observed no significant placenta AVP clearance; however, their results are not conclusive since the low perfusion rate used would not be expected to produce a decrease in AVP concentra tion should placenta clearance have occurred. We found similar MCR val ues for AVP in fetuses and lambs suggesting that placental AVP clearance contributes insignificantly to fetal AVP metabolism.…”

Section: Discussionmentioning

confidence: 86%

Arginine Vasopressin Metabolie Clearance and Production Rates in Fetal Sheep, Pregnant Ewes, and Lambs

Stegner¹,

Leake²,

Palmer³

et al. 1984

Dev Pharmacol Ther

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Arginine vasopressin (AVP) metabolic clearance rates (MCR) and production rates (PR) were measured in chronically catheterized fetuses, maternal ewes (130-135 days of gestation), and 1 - to 6-month-old sheep using constant infusion noncompartmental kinetic methodology. No significant differences in mean basal plasma A VP levels, MCR rates or PR were found among the fetuses, maternal ewes or lambs. MCR of AVP did not change with steady-state plasma AVP levels varying from 2 to 68 μU/ml. Neither the placenta nor the fetal kidney appear to play a significant role in AVP metabolic clearance.

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“…Basal levels of AVP are nearly identical in maternal and fetal plasma [1,6], The fetus appears to respond autonomously, however, to osmotic and nonosmotic stimuli since there is little correlation of stimulated A VP levels in maternal and fetal plasma [2,6,12,13], In addition, we reported earlier that following infusion of 10 units of synthetic A VP into the fetal circulation of chronically catheterized sheep, no increase in maternal plasma A VP concentrations could be measured [6]. In contrast, Forslinget al [3] using a recirculation system to perfuse the guinea pig placenta found AVP transfer from the maternal site to the perfusate in 4 of 7 animals following in vivo injection of 25-50 mU AVP in the maternal circulation prior to sacrifice. When 40 mU AVP were added to the perfusate, no increase in AVP concentrations could be mea sured on the maternal side.…”

Section: Introductionmentioning

confidence: 83%

Permeability of the Sheep Placenta to ^125I-Arginine Vasopressin

Stegner¹,

Leake²,

Palmer³

et al. 1984

Dev Pharmacol Ther

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We studied the permeability of the ovine placenta to AVP. ^125I-AVP (9.3 ± 1.9 mU) with approximately 82 (± 17.3) X 10^6 counts per 5 min were infused intravenously in 6 pregnant ewes. Six blood samples were collected at 10-min intervals over a 1-hour period from chronically catheterized maternal and fetal sheep. ^125I-AVP in maternal and fetal plasma samples (1 ml each) were counted in a gammacounter for 5 min. Maternal counts decreased from 9,300 to 2,500 counts per 5 min over the hour following infusion but no increase in radioactivity could be measured in fetal blood, indicating that the sheep placenta is impermeable to ^125I-AVP.

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Permeability of the Foetal Guinea-Pig Placenta to Arginine-Vasopressin

Cited by 5 publications

References 4 publications

Effect of Haemorrhage on Plasma Lysine Vasopressin and the Cardiovascular Responses to Vasopressin in the Pig Fetus

Effect of Haemorrhage on Plasma Lysine Vasopressin and the Cardiovascular Responses to Vasopressin in the Pig Fetus

Arginine Vasopressin Metabolie Clearance and Production Rates in Fetal Sheep, Pregnant Ewes, and Lambs

Permeability of the Sheep Placenta to ^125I-Arginine Vasopressin

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