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Biomedical subjects

I Iwata

Publications and source records attributed to I Iwata.

35 records · Page 2Linked to original sources

Plasma concentrations of human atrial natriuretic peptide at vaginal delivery and elective cesarean section.

The change in plasma concentration of atrial natriuretic peptide (hANP) at delivery was examined by measuring the concentrations of hANP in plasma samples from 21 subjects after 36 weeks of normal pregnancy, 22 subjects after normal spontaneous delivery and 20 subjects after elective cesarean section. The maternal plasma concentration of hANP after normal delivery (38.0 +/- 8.2 fmol/ml, mean +/- S.E.M.) was significantly higher than that after 36 weeks of normal pregnancy (16.8 +/- 2.3 fmol/ml), but its concentration after cesarean section was not different from that after 36 weeks of pregnancy. After normal delivery, the plasma concentration of hANP in the umbilical artery (66.9 +/- 11.8 fmol/ml) was also significantly higher than that in the umbilical vein (35.1 +/- 7.3 fmol/ml). In contrast, after elective cesarean section, the hANP levels in the umbilical artery and vein were not significantly different. These results suggest that hANP secretion into the maternal and fetal circulation may be stimulated by the dynamic movement of the mother in labour and the stress of the fetus at delivery, respectively.

Adult↗

Changes in concentration of human atrial natriuretic peptide in normal pregnancy and toxaemia.

Changes in concentration of human atrial natriuretic peptide (hANP) in normal and toxaemic pregnancy were examined. The maternal plasma concentration of hANP increased gradually during normal pregnancy to a maximum of 20.0 +/- 2.4 pmol/l (mean +/- S.E.M.) after week 36 of pregnancy. From week 20, the plasma concentrations of hANP were significantly higher than those in non-pregnant women (9.3 +/- 2.0 pmol/l). In toxaemia with hypertension, maternal plasma hANP levels were increased after week 26 of pregnancy (37.7 +/- 6.0 pmol/l) compared with those in normal gravida at the same time (17.1 +/- 1.6 pmol/l). Maternal plasma hANP levels in toxaemia only with oedema were not different from those in normal gravida.

Adult↗

The effect of maternal antigenic stimulation upon the active immune responsiveness of their offspring: suppression induced by soluble protein antigen, ovalbumin, in mice.

The active immune responsiveness of the offspring of pregnant mice stimulated with heterologous protein antigen was investigated by measuring the plaque-forming cells (PFC). Mice (C57BL/10;B10) immunized once in pregnancy with ovalbumin (OVA) in the form of Al(OH)3 gel (in alum) or in a soluble form (in saline) developed no anti-OVA PFC response. The anti-OVA PFC response suppression induced in the offspring was high in the offspring of alum-treated mothers and low in those of saline-treated mothers. The optimal dose of OVA in alum that induces the highest immunological memory in pregnant mice caused the complete suppression of PFC development in their offspring. The same dose of OVA in saline induced a negative immunological memory in pregnant mice and partial suppression in the offspring. On the other hand, mice primed prior to conception and boosted during pregnancy developed anti-OVA PFC in significant numbers, and only a partial suppression was established in their young. Based on these data, we discussed the possible mechanisms concerned with the specific suppression induced in the young B10 mice stimulated by OVA.

Animals↗