Maternal Oxygen Research Articles

Alternatives à l'analgésie péridurale au cours du travail

Many systemic techniques, so-called « alternatives » to labor epidural analgesia, have been described: they are all poorly effective and some are associated with significant maternal and neonatal side effects. Nonetheless, these techniques can provide good maternal satisfaction. Accordingly, they are indicated when epidural analgesia is contraindicated or unavailable. Administration of systemic opioids mandates maternal respiratory supervision, oxygen supplementation and/or pulse oxymetry. Systemic opioids may also decrease fetal heart rate variability and produce neonatal respiratory depression; naloxone administration to the neonate is therefore widely indicated. Pethidine should be abandoned because it can produce prolonged neonatal respiratory depression. Nalbuphine produces less nausea/vomiting and less long lasting neonatal respiratory depression. Intravenous PCA fentanyl or sufentanil is presently the method of choice during early labor. Alfentanil seems less effective and may produce more neonatal side effects. Intravenous PCA remifentanil is the most effective technique, but safe administration may be problematic during intermittent supervision usually implemented in labour ward. Nitrous oxide 50% provides little pain relief. Nonetheless, it is associated with few side effects, quite good maternal satisfaction and can be quickly implemented during advanced painful labor. It is not recommended to add it to systemic opioid (except under continuous supervision by the anaesthetic team), because of an increased incidence of maternal desaturation. The use of a subanaesthetic concentration of sevoflurane has been described recently; it is more effective than nitrous oxide. However, guidelines for safe implementation in labor ward remain to be determined.

Ex utero intrapartum procedure for delivery of a fetus with a large cervical mass

Ex utero intrapartum procedure for delivery of a fetus with a large cervical mass

Effects of maternal hypoxia or nutrient restriction during pregnancy on endothelial function in adult male rat offspring

Compromised fetal growth impairs vascular function; however, it is unclear whether chronic hypoxia in utero affects adult endothelial function. We hypothesized that maternal hypoxia (H, 12% O2, n= 9) or nutrient restriction (NR, 40% of control, n= 7) imposed from day 15-21 pregnancy in rats would impair endothelial function in adult male offspring (relative to control, C, n= 10). Using a wire myograph, endothelium-dependent relaxation in response to methacholine was assessed in small mesenteric arteries from 4- and 7-month-old (mo) male offspring. Nitric oxide (NO) mediation of endothelium-dependent relaxation was evaluated using N(omega)-nitro-L-arginine methyl ester (L-NAME; NO synthase inhibitor). Observed differences in the NO pathway at 7 months were investigated using exogenous superoxide dismutase (SOD) to reduce NO scavenging, and sodium nitroprusside (SNP; NO donor) to assess smooth muscle sensitivity to NO. Sensitivity to methacholine-induced endothelium-dependent relaxation was reduced in H offspring at 4 months (P < 0.05), but was not different among groups at 7 months. L-NAME reduced methacholine sensitivity in C (P < 0.01), H (P < 0.01) and NR (P < 0.05) offspring at 4 months, but at 7 months L-NAME reduced sensitivity in C (P < 0.05), tended to in NR (P= 0.055) but had no effect in H offspring. SOD did not alter sensitivity to methacholine in C, but increased sensitivity in H offspring (P < 0.01). SNP responses did not differ among groups. In summary, prenatal hypoxia, but not nutrient restriction impaired endothelium-dependent relaxation at 4 months, and reduced NO mediation of endothelial function at 7 months, in part through reduced NO bio-availability. Distinct effects following reduced maternal oxygen versus nutrition suggest that decreased oxygen supply during fetal life may specifically impact adult vascular function.

Patient controlled analgesia for labour: a comparison of remifentanil with pethidine*

We compared the analgesic efficacy and safety of remifentanil and pethidine via patient controlled analgesia for women in established uncomplicated labour. Women received either remifentanil 40 microg with a 2-min lockout (n = 20) or pethidine 15 mg with a 10-min lockout (n = 19). Visual analogue scores for pain during the study and for overall pain were similar for both groups (mean (SD) 6.4 (1.5) cm for remifentanil and 6.9 (1.7) cm for pethidine). The area under the curve for visual analogue scores of satisfaction with analgesia was higher for remifentanil than for pethidine (p = 0.001). Maternal arterial oxygen saturation was similar in both groups. Neurologic and Adaptive Capacity Scores at 30 min were higher for remifentanil than for pethidine (median (interquartile range [range]) 36 (34.5-37 [32-39]) vs 34 (33-35 [30-35]), respectively; p = 0.003).

Differential effects of maternal hypoxia or nutrient restriction on carotid and femoral vascular function in neonatal rats

In response to reduced oxygen or nutrient supply, the fetus may redistribute cardiac output to conserve brain and heart growth, at the expense of the peripheral tissues; however, it is not known whether alterations in vascular function are maintained after birth or whether reduced fetal oxygen versus nutrient supply produces distinct effects. Using a pressure myograph, we examined isolated carotid and femoral artery responses to phenylephrine and endothelin-1 in neonatal rats, after either reduced maternal oxygen or global nutrient restriction during late gestation. Timed-pregnant Sprague-Dawley rats were randomly assigned to control (n = 10), hypoxia (12% O2, n = 9), or nutrient restriction (NR, 40% of control diet, n = 7) protocol and treated from day 15-21 of pregnancy. Pups were collected 3-12 h after birth. Neonatal weights (P < 0.001) and relative liver weights (P < 0.001) were lower in hypoxia and nutrient restriction treatments compared with control, while relative heart weights were greater in the hypoxia than in the control or nutrient restriction groups (P < 0.01). Constriction to phenylephrine was reduced in carotid arteries from the hypoxia and nutrient restriction groups compared with control (P < 0.001), while the femoral artery response was greater in hypoxia-treated neonates compared with control or nutrient-restricted neonates (P < 0.01). Only the hypoxia reduced carotid responses to endothelin-1, while no differences were observed in the endothelin-1 responses in femoral arteries. Maternal hypoxia and maternal nutrient restriction produced distinct effects on heart growth and neonatal vascular function, suggesting that regional changes in cardiovascular function after poor fetal growth are dependent on the nature of the insult in utero.

Fetal effects of maternal supplementary oxygen during Caesarean section

This review summarises the current issues, knowledge and research on the effects of maternal supplementary oxygen therapy on the fetus during Caesarean section. This is a controversial subject since supplementary oxygen has the potential to confer both benefits and also harm to the fetus, depending on the circumstances. For elective Caesarean section, breathing room air under regional anaesthesia or 30% oxygen under general anaesthesia is not associated with either maternal or fetal hypoxia. A prolonged uterine-incision-to-delivery (U-D) interval of up to 310 s is not a major factor per se for development of fetal hypoxia or acidosis, and no benefits could be derived from breathing supplementary oxygen in this situation. Although it appears rational to provide supplementary oxygen in the presence of a hypoxic or compromised fetus, to achieve meaningful increases in fetal oxygenation, a very high inspired oxygen fraction (FiO2) is required. However, it still remains unclear whether this is beneficial for the fetus. The process of damage to the hypoxic fetus is one of oxidative stress mediated by free radicals generated during reperfusion (ischaemia-reperfusion injury). Independently, hyperoxia from breathing supplementary oxygen also induces formation of free radicals by direct mitochondrial electron transfer. Although hyperoxia could lessen the severity of fetal hypoxia, there is also a theoretical risk of an enhanced reperfusion injury. This issue has not been resolved in a clinical study, but an animal study reported enhanced formation of free radicals after an episode of fetal hypoxia in the group receiving supplementary oxygen. For elective Caesarean section, current evidence suggests that supplementary oxygen is unnecessary. For emergency Caesarean section, further data are required before a conclusion can be made for its beneficial and adverse effects. Improvement of fetal oxygenation should be the primary objective, and this is achievable in the short term by using a very high FiO2. Although there is also a possibility of an enhanced reperfusion injury, particularly in the preterm and non-labouring patients, further data are necessary before a conclusion can be made.

The effects of hypoxia on growth cones in the ovine fetal brain

Objective: This study was designed to investigate the effects of hypoxia on neural process proliferation by studying its effects on growth cone tubulin and insulin-like growth factor (IGF)-I receptor content.Methods: Six fetal lambs were catheterized in the brachial artery and vein. Maternal oxygenation was reduced in steps from a fractional inspired oxygen concentration (FiO2) of 20% to 6% by addition of nitrogen to the inhaled gas mixture for a period of 4 h of reduced oxygen intake. Fetal arterial blood was sampled after the maternal FiO2 and oxygen were stable for > 5 min at maternal FiO2 of 20% to 6%. Controls were obtained from normoxic fetuses whose ewes had similar surgery and were kept at an FiO2 of 20% throughout the experiment. Growth cones were isolated from the fetal cerebrum and cerebellum. α-Tubulin and IGF-I receptors were quantified by immunoblotting. Tubulin and IGF-I receptor mRNA expressions were quantified by real-time polymerase chain reaction.Results: Maternal nitrogen breathing reduced fetal arterial pH from 7.32 ± 0.06 to 6.99 ± 0.02 (p < 0.001). Hypoxia increased IGF-I receptors from 143 ± 10 to 327 ± 14 (p < 0.001) and from 272 ± 26 to 396 ± 34 (p < 0.001) fluorescence units/μg protein in the cerebrum and cerebellum, respectively. It also increased α-tubulin from 713 ± 30 to 1873 ± 126 (p < 0.001) and from 780 ± 34 to 2362 ± 79 (p < 0.001) fluorescence units/μg protein in the cerebrum and cerebellum, respectively. Expression of IGF-I receptor mRNA increased significantly in the hypoxic animals both in the cerebrum and the cerebellum, but there was no change in expression of α-tubulin mRNA.Conclusions: This increase in IGF-I receptor expression and growth cone content may be an adaptive response to hypoxia to maintain neurite growth by facilitating binding of IGF-I. Hypoxia also increased the growth cone level of α-tubulin but did not increase its mRNA expression, which may indicate an inability to polymerize tubulin and build microtubules.

Effects on the fetus and newborn of maternal analgesia and anesthesia: a review

To review the effects of maternal anesthesia and analgesia on the fetus and newborn. An on-line computerized search of Medline, Embase, and the Cochrane Collaboration via PubMed was conducted. English language articles were selected. The bibliographies of relevant articles and additional material from other published sources were retrieved and reviewed. No one test clearly separates the effects on the fetus/newborn, if any, of maternally administered medication during labour and delivery, or during surgery for non-obstetric indications. Supposition in this regard is limited in part by methodology previously used to study the transplacental passage of various drugs. This work needs to be repeated using a human model. Routine maternal supplemental oxygen administration is being questioned in light of research showing that free radical generation and oxidative stress are implicated as the underlying mechanisms in several neonatal conditions. Maternal hypotension is associated with neonatal acidemia and base excess correlates with neonatal outcome. Common postpartum analgesics transfer minimally into breast milk. Maternal or fetal surgery conducted during pregnancy necessitates modification of both anesthetic and surgical approaches. The key to resuscitation of the fetus is resuscitation of the mother: intra-uterine maneuvers, including perimortem Cesarean section, aim to reverse treatable causes of fetal asphyxia, restore fetal oxygenation, and correct fetal acidosis. The well-being of the infant is a major criterion for evaluating the anesthetic management of pregnant women. Many tools exist to assist with this determination for the fetus, whereas few are available to evaluate the newborn.

Cardiac Disease in Pregnancy

After completing this article, readers should be able to: 1. Describe how the cardiovascular changes of pregnancy can affect the woman who has cardiac disease. 2. Review the importance of preconception counseling. 3. Discuss the purpose of a multidisciplinary team approach to the management of the woman who has cardiac disease during pregnancy. 4. Review delivery management of women who have cardiac disease. Pregnancy causes considerable physiologic change in women, particularly in their cardiovascular systems. Circulating blood volume increases dramatically, and cardiac output increases up to 50% by the end of pregnancy. Pregnant women who have cardiac disease must be able to accommodate these normal changes to have a successful pregnancy. Inability to do so can result in increased morbidity and mortality. Cardiac disease is an important cause of nonobstetric mortality during pregnancy and can result in significant morbidity. (1)(2) Approximately 10% of all maternal deaths in the United States can be attributed to cardiac disease, a number that has remained consistent for the last half century. (1) In one study of 1,000 pregnant women who had various types of cardiac disease and were followed by the same health-care team over a 10-year period, more than 75% of the women had no complications during pregnancy. (2) Among the remaining 25%, the following complications were seen most often: The overall maternal mortality rate in this group was 2.7%, and the stillbirth and spontaneous abortion rate was 7.7%. Cardiac disease covers a wide range of conditions, including congenital heart disease, acquired disease such as rheumatic valvular disease, and coronary disease. It is estimated that 1% to 3% of women either have cardiac disease entering pregnancy or are diagnosed with cardiac disease while they are pregnant. …

Long-term hypoxia alters endocrine and physiologic responses to umbilical cord occlusion in the ovine fetus.

This study was designed to determine the effect of umbilical cord occlusion (UCO) on fetal endocrine responses in the long-term hypoxemic (LTH) ovine fetus. Pregnant ewes were maintained at high altitude (3820 m) from day 30 of gestation. Normoxic control and LTH fetuses were catheterized, and an inflatable occluder was placed on the umbilical cord at day 132 of gestation. In the LTH group, maternal oxygen tension was maintained at approximately 60 mmHg by nitrogen infusion through a maternal tracheal catheter. On day 137, two 5-minute UCOs were performed. On day 139, the study was repeated with a 10-minute UCO. Basal adrenocorticotropic hormone (ACTH) levels and peak responses to the first 5-minute UCO were not different between control and LTH fetuses (17.6 +/- 4.0 to 418.8 +/- 41.3 in controls, 25.7 +/- 4.0 to 530.0 +/- 93.0 pg/mL in LTH fetuses). A similar pattern was observed during the second UCO. Basal cortisol levels were similar in both groups. In response to UCO, a significant increase in cortisol was observed in both groups, but peak concentrations in the LTH group were significantly higher than those in the control group (23.9 +/- 4.8 versus 14.8 +/- 2.9 ng/mL, respectively, P <.05). The second occlusion also increased cortisol concentrations, but no differences were observed between groups. After the 10-minute UCO, the ACTH and cortisol responses were similar to the first 5-minute occlusion, with higher cortisol levels in the LTH fetuses. Despite similar ACTH responses to UCO, the cortisol response was greater in the LTH fetuses than in normoxic controls. LTH appears to result in enhanced adrenal sensitivity to a secondary stressor or altered cortisol metabolism.

Arterial oxygen tension during sleep in the third trimester of pregnancy.

Changes during pregnancy include reduced functional residual capacity (FRC) and residual volume (RV), increased alveolar difference for oxygen and, in the supine position, reduced cardiac output. In conjunction with sleep-related disturbances, these changes could lead to maternal oxygen desaturation during sleep. Because of conflicting data from respiratory sleep studies in pregnancy, we performed complete polysomnography on 21 pregnant women at the 36th week of gestation and again postpartum. We also measured the partial pressure of oxygen in the arterial blood (PaO2) in the supine and sitting positions. We tested 21 healthy pregnant women at the 36th week of gestation. Arterial samples were taken in the sitting position. Complete polysomnography was performed in all of the pregnant women. Before the polysomnography arterial samples were taken in the supine and sitting positions and then every 2 h until termination of the study. We did not find any correlation between SaO2/PaO2 levels and apnea, hypopnea or percent of rapid eye movement (REM) sleep. The frequency of apnea and hypopnea was significantly lower during pregnancy (5.81 +/- 2.1 apneas or hypopneas per hour of sleep) than postpartum (12.1 +/- 2.7 apneas or hypopneas per hour of sleep) (p < 0.001), which may be due to the raised level of progesterone. The PaO2 levels in the supine position were significantly lower than in the sitting position at 36 weeks of gestation (p < 0.001). No differences were found between PaO2 levels in the sitting and supine positions postpartum (p < 0.5). According to our results we conclude that 1) the frequency of apnea and hypopnea in pregnancy was significantly lower than postpartum, and 2) a significant difference in PaO2 levels in the sitting and supine positions was observed at 36 weeks of gestation.

Maternal oxygen administration for fetal distress.

Maternal oxygen administration has been used in an attempt to lessen fetal distress by increasing the available oxygen from the mother. This has been used for suspected fetal distress during labour, and prophylactically during the second stage of labour on the assumption that the second stage is a time of high risk for fetal distress. The objective of this review was to assess the effects of maternal oxygenation for fetal distress during labour and to assess the effects of prophylactic oxygen therapy during the second stage of labour on perinatal outcome. We searched the Cochrane Pregnancy and Childbirth Group trials register (March 2003) and the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 3, 2002). Randomised trials comparing maternal oxygen administration for fetal distress during labour and prophylactic oxygen administration during the second stage of labour with a control group (dummy or no oxygen therapy). Both reviewers assessed eligibility and trial quality. Data were extracted, checked and entered into RevMan software. For dichotomous data, relative risks (RR) and 95% confidence intervals (CI) were calculated. For continuous data, weighted mean differences and 95% CI were calculated. No trials addressing maternal oxygen therapy for fetal distress were located. Two trials which addressed prophylactic oxygen administration during labour were included. Abnormal cord blood pH values (less than 7.2) were recorded significantly more frequently in the oxygenation group than the control group (relative risk 3.51, 95% confidence interval 1.34 to 9.19). There were no other statistically significant differences between the groups. There were conflicting conclusions on the effect of the duration of oxygen administration on umbilical artery pH values between the two trials. Implications for practiceThere is not enough evidence to support the use of prophylactic oxygen therapy for women in labour, nor to evaluate its effectiveness for fetal distress. Implications for researchIn view of the widespread use of oxygen administration during labour and the possibility that it may be ineffective or harmful, there is an urgent need for randomised trials to assess its effects.

Normal pregnancy and oxygenation during sleep

Pregnancy is associated with significant alterations in respiratory function. Changes during pregnancy include reduced functional residual capacity (FRC) and residual volume (RV), increased alveolar-arterial difference for oxygen (A-αPO 2) and in the supine position, reduced cardiac output. In conjunction with sleep-related apneas or hypopneas, these could lead to maternal oxygen desaturation during sleep. Because of the conflicting data from sleep studies in late pregnancy, we performed complete polysomnography on 11 pregnant women at 36 weeks of gestation and again postpartum. We also measured the PaO 2, every 2 h. The frequency of apneas and hypopneas was significantly lower during pregnancy compared with that on the postpartum control night. PaO 2 levels in the supine position, during sleep, were also significantly lower during pregnancy compared to the postpartum period. No correlation was observed between PaO 2 levels and apneas or hypopneas or percent of REM sleep.

The placenta at high altitude.

The influence of oxygen pressure on placental and villous vascular development is reviewed and considered relative to the natural experiment afforded by residence at high altitude. Data obtained from normal high altitude pregnancies are compared with those from IUGR and preeclampsia, conditions believed to be caused by placental hypoxia. High altitude placentas are characterized by increased villous vascularization, thinning of the villous membranes, proliferation of the villous cytotrophoblast, and reduced perisyncytial fibrin deposition relative to low altitude placentas. The significance of reduced fibrin deposition is unknown; it could be explained by less apoptosis along the barrier membrane, less syncytiotrophoblast turnover, or altered ratios of local proversus anticoagulant production. Increased villous capillary density and thinning of the villous membranes increases oxygen diffusion capacity and is generally considered a beneficial adaptation. Nonetheless, there is evidence that hypoxia and/or reduced blood flow reduce placental nutrient transporter densities, and this may act in additive or synergistic fashion to reduce birth weight at high altitude. The available literature on high altitude placentas derives from less than 100 pregnancies from three different continents and six different ethnic groups, and were acquired in pregnancies ranging from 2500 to 4300 m in altitude. Thus differences between studies are likely to be due to variation in altitude and/or to ethnic variation, which in turn may be due to differences in population history of residence at high altitude (e.g., Andeans vs. Europeans). Nonetheless, systematic examination of human placental development under conditions of lowered maternal arterial oxygen pressure (high altitude > 2700 m) may provide useful insights into the etiology of pathological conditions believed to be associated with placental hypoxia.

Fetal growth restriction and maternal oxygen transport during high altitude pregnancy.

High altitude reduces birth weights, averaging a 100-g fall per 1000 m elevation gain, as the result of restriction of third trimester fetal growth. Intrauterine growth restriction (IUGR) raises neonatal or infant mortality at low as well as at high altitude, but existing studies are unclear as to whether IUGR-specific mortality at high altitude is similar to, less than, or greater than at low altitude. Pregnancy increases maternal ventilation and raises arterial O(2) saturation at high altitude, which helps to protect against altitude-associated IUGR. Chronic hypoxia interferes with the maternal circulatory adjustments to pregnancy such that blood volume is lower and the rise in cardiac output diminished compared with sea level. The growth and remodeling of the uterine artery and other uteroplacental vessels is incomplete at high compared with low altitude, with the result that there is less redistribution of common iliac flow from the external iliac to the uterine arteries and lower uterine artery blood flow near term. Adaptations in multigenerational high altitude populations (e.g., Andeans and Tibetans) permit higher uterine artery blood flows and protect against altitude-associated IUGR.

Maternal oxygen administration for suspected impaired fetal growth.

Fetal hypoxaemia is often a feature of fetal growth impairment. It has been suggested that perinatal outcome after suspected impaired fetal growth might be improved by giving mothers continuous oxygen until delivery. The objective was to assess the effects of maternal oxygen therapy in suspected impaired fetal growth on fetal growth and perinatal outcome. We searched the Cochrane Pregnancy and Childbirth Group trials register and the Cochrane Controlled Trials Register. Acceptably controlled trials comparing maternal oxygen therapy with no oxygen therapy in suspected impaired fetal growth. Eligibility and trial quality was assessed. Two studies involving 62 women were included. Oxygenation compared with no oxygenation was associated with a lower perinatal mortality rate (relative risk 0.41, 95% confidence interval 0.21 to 0.78). However higher gestational age in the oxygenation groups may have accounted for the difference in mortality rates. There is not enough evidence to evaluate the benefits and risks of maternal oxygen therapy for suspected impaired fetal growth.

Effects of maternal oxygen supplementation on fetal oxygenation and lipid peroxidation following a single umbilical cord occlusion in fetal goats.

Maternal oxygen supplementation is commonly performed to improve fetal oxygenation and acid-base balance during fetal asphyxia. The efficiency of this treatment is controversial, which may be associated with the production of oxygen free radicals and lipid peroxidation. However, only a few studies have been performed to evaluate these issues. To clarify them, we investigated the effects of maternal oxygen supplementation on fetal oxygenation and lipid peroxidation following fetal asphyxia in late gestation goats. We measured fetal blood gases, pH and plasma malondialdehyde (MDA), one of the endproducts of lipid peroxidation, before, during and after fetal asphyxia with and without maternal oxygenation in late gestation goats. Fetal asphyxia was induced by a single total umbilical cord occlusion of 3 minutes' duration, and maternal oxygenation was initiated at 20 min before the cord occlusion and terminated at 20 min after the release of cord occlusion. Maternal oxygen supplementation resulted in a significant increase in fetal PaO(2) before and after the cord occlusion (p<0.05). During the cord occlusion, the extents of hypoxia and acidemia were not changed by maternal oxygen supplementation. Fetal plasma MDA levels before maternal oxygen supplementation averaged 0.80+/-0.04 micromol/L, significantly increased after the initiation of maternal oxygen supplementation (1.11+/-0.07 micromol/L), and further increased following fetal asphyxia (1.28+/-0.06 micromol/L), and after the release of the cord occlusion (1.58+/-0.7 micromol/L)(p<0.05). These values were significantly higher than those in fetuses without oxygenation. We conclude that maternal oxygen supplementation increased fetal oxygenation but caused a concomitant increase in lipid peroxidation in the fetus.

A longitudinal study of maternal oxygen saturation during short-term submaximal exercise.

Longitudinal prospective study before, during and after normal pregnancy of the effect of short-term submaximal exercise on maternal oxygen saturation. Fourteen healthy women were recruited to the study before a planned pregnancy, and were followed seven times during the pregnancy and for up to 6 month after delivery. A submaximal bicycle exercise test with a target heart rate of 85% of the predicted age-adjusted maximum was performed. Maternal oxygen saturation was continuously recorded using a pulse oximeter. Maternal oxygen saturation at maximum work-load had increased significantly already at 8 weeks gestation compared with preconception levels, and remained at a significantly higher level until 29 weeks of gestation. Thereafter, the oxygen saturation continued to be higher even at 6 month postpartum. During the exercise test, the lowest saturation was found during the late recovery period, this remained unchanged before, during and after pregnancy. A pregnant woman responds to short-term exercise by increasing the oxygen saturation until 29 weeks. After that, the saturation level decreases but remains at a higher level even 6 month after delivery compared with preconception levels.

Effects of High Inspired Oxygen Fraction During Elective Caesarean Section Under Spinal Anaesthesia on Maternal and Fetal Oxygenation and Lipid Peroxidation

Effects of High Inspired Oxygen Fraction During Elective Caesarean Section Under Spinal Anaesthesia on Maternal and Fetal Oxygenation and Lipid Peroxidation

홍삼 사포닌이 수태중인 흰쥐의 항산화 효소활성에 미치는 영향

수태는 많은 신체적인 기능들의 높은 에너지 요구 및 산소요구량 증가로 인하여 생리적인 변화를 수반한다. 때문에 산소 섭취량 및 이용이 증가하여 산화적인 스트레스의 증가를 기대할 수 있다. 수태중에 발생되는 free radical에 대하여 홍삼사포닌 투여가 간 항산화효소의 활성에 미치는 영향을 연구하였다. 수태중에 superoxide dismutase(SOD)의 활성은 전반적으로 감소하는 경향을 나타냈으며, 사포닌 투여군은 대조군에 비하여 유의한 변화가 관찰되지 않았다. 그리고 glutathione peroxidase(GPX) , gluthatione reductase (GRD)와 catalase의 활성도는 수태중에 감소하는 경향을 나타냈으며, 반면에 사포닌 투여군은 대조군 비하여 GRD 및 catalase의 활성도에 유의한 변화를 나타냈다. 사포닌 투여군의 GPX의 활성도는 대조군에 비하여 감소하는 경향이 다소 적게 나타났다. 수태중 대조군의 glutathione-S-transferase (GST) 활성도는 항상성을 유지하기 위해 증가하는 경향을 나타냈으며, 사포닌 투여군도 대조군에 비하여 이 효소의 활성도가 더욱 증가하는 경향을 나타냈다. 분만 후 대조군 및 사포닌 투여군은 정상수준으로 회복되었다. 수태와 같은 생체변화에도 불구하고 수태한 흰쥐의 간 항산화 효소활성에 대한 사포닌의 영향은 산소독성에 대하여 모체간을 보호해주는 생리적 항상성의 적응메카니즘에 의하여 조절되는 것으로 보인다. Pregnancy is a physiological state accompained by a high energy demand of many bodily functions and an increased oxygen requirement. Because of the increased intake and utilization of oxygen, increased levels of oxidative stress would be expected. So we observed the activities of the hepatic antioxidant enzymes from rat treated with total saponin from the red ginseng against free raicals produced in pregnant rats. The activity of superoxide dismutase (SOD) in the control group was slightly decreased during pregnancy, and SOD activity in total saponin treated group was not observed any siginificant change compared with the control group. The activities of glutathione peroxidase (GPX), glutathione reductase (GRD) and catalase in the control group have shown the decreasing tendency during pregnancy, whereas the activities of GRD and catalase in total saponin treated group showed significant increased tendency compared with the control group. GPX activity in total saponin treated group was slightly decreased tendnency compared with the control group. The activity of glutathione-S-transferase (GST) in the control group was increased to keep the state of homaeostasis tendency in pregnant rats. On the other hand, the activity of GST after total saponin treatment was increased than control group. Activity of all enzymes in the control group and total saponin treated group recovered the normal level after delivery of rats. In spite of the physiological changes in vivo, the inflaunce of total saponin on activaties of hepatic antioxidant enzyme in pregnant rats seems to be regulated the biological homeostatic adaptation mechanism which protects the maternal liver aganist oxygen induced toxicity