Group I3 Research Articles

Effects of Different Sources of Culture Substrate on the Growth and Immune Performance of the Red Swamp Crayfish (Procambarus clarkii).

The substrate in the aquatic environment plays a crucial role in nutrient deposition and recovery for the growth of aquatic organisms. In order to optimize the culture medium of Procambarus Clarkii, culture media from different sources were selected in this study to explore their effects on the growth and immune performance of red swamp crayfish. The results showed that the weight gain rate (WGR), body length growth rate (BLGR) and specific growth rate (SGR) in group I2 were the highest, followed by group I1 and group I3. The WGR and SGR of crayfish in the I1 and I2 groups were significantly higher than those in the I3 group (p < 0.05). The activities of acid phosphatase (ACP), alkaline phosphatase (AKP) and superoxide dismutase (SOD) were the highest in group I2, followed by group I3, and the lowest in group I1. The expression trends in growth-related genes, nuclear hormone receptor (E75), molt-inhibiting hormone (MIH) and chitinase genes were similar, and the expression levels in the I2 group were higher than those in the I1 and I3 groups. It was noted that the expression levels of E75 and MIH genes in the I2 group were significantly higher than those in the I3 group (p < 0.05). α diversity analysis of 16S rRNA data showed that there was no statistically significant difference in the abundance of intestinal flora among the three culture substrate groups. The β diversity in the Xitangni group, crayfish Tangni group and Shuitangni group was significantly different. These changes in microbiota suggest that using different substrates to culture crayfish leads to differences in gut microbiota diversity. To sum up, the growth in crayfish and immune performance influenced by the culture substrate condition and aquatic breeding sediment substrates, rather than crab pool and paddy field pond sediment substrates, showed a better effect.

The anti-cariogenic effect of fluoride iontophoresis on sound enamel under different working conditions: an in vitro study

Objective. This study investigated the anti-cariogenic effect of fluoride iontophoresis on sound human enamel under different working conditions. Methods. One hundred and five enamel blocks were prepared and randomly assigned to seven different groups: Fluoride iontophoresis under different working conditions, including: different electric current intensities (0.2, 0.4, 0.6 mA) and durations of current application (3, 6, 9 min); No fluoride treatment (negative control); Fluoride immersion without iontophoresis (positive control). After 7 days of pH-cycling, morphology changes on enamel surfaces were examined by scanning electron microscopy (SEM), and Vickers surface microhardness (VH) values of enamel blocks before and after treatments were assessed using a Vickers microhardness tester. KOH-soluble fluoride (KOH-F) uptakes were measured by a fluoride ion-selective electrode. Results. Distinctly roughened enamel surfaces were showed in all treatment groups, with the greatest extent damaged surface in negative control group and the least in all the fluoride intophoresis groups. All the fluoride iontophoresis groups (except for the group under 0.2 mA) showed smaller reduction of VH values (p < 0.05) and greater KOH-F (p < 0.05) when compared with the negative and positive control groups. There was an increasing trend in the loss of VH and in fluoride uptakes with an increasing current intensity. Meanwhile, the reduction of VH values and KOH-F in Group I3 ( 0.6 mA) were significantly greater (p < 0.05) than those in Group I1 ( 0.2 mA). No significant differences of reduction of VH and KOH-F presented among the three groups applied with fluoride iontophoresis under different current durations. Conclusions. Fluoride iontophoresis resulted in a significantly increased KOH-F and a reduced loss of VH after the 7 days pH-cycling procedure, and its effectiveness was influenced by different electric current intensities but not influenced by different current durations.

Comparative immunohistochemical assessment of the effect of repetitive anesthesia with isoflurane and sevoflurane on rat liver

Inhalation anesthetics are used in human, as well as veterinary medical practice. In the present study we investigated the effect of isoflurane and sevoflurane on rat hepatocytes. A total of 40 Wistar female rats were used in this study. Animals were divided in groups of 5 rats. Groups IM, SM served as control groups. Groups I1, I2, I3 were used to study isoflurane and S1, S2, S3 for sevoflurane study. They were anesthetized 3 times, for 2h long, at 2 days interval with a concentration of: 1.5% isoflurane (I1, I2, I3) and 2% sevoflurane (S1, S2, S3). The oxygen supply throughout the anesthesia was 1LO2/min. Groups IM, IS, I1, S1 were sacrificed immediately after the last anesthesia. Groups I2, S2 were sacrificed 6h after the last anesthesia, and groups I3, S3, 24h post-anesthesia. Liver samples were harvested to highlight caspase-3 in apoptotic hepatocytes. Following isoflurane administration, there were less than 1% cells in apoptosis highlighted in rat livers from groups IM, I1 and I2. At 24h post-anesthesia (group I3), a small number of apoptotic hepatocytes was highlighted (around 3.23% cells in apoptosis), with a strictly periacinar disposition, randomly distributed in a small number of hepatic lobules. After sevoflurane administration, less than 1% apoptotic hepatocytes were identified at all control moments throughout the study. The results suggest that the anesthetics do not present a considerable hepatotoxicity. The comparative assessment of the two anesthetics shows that sevoflurane is superior to isoflurane.

Comparative immunohistochemical assessment of the effect of repetitive anesthesia with isoflurane and sevoflurane on rat liver

Background and objectivesInhalation anesthetics are used in human, as well as veterinary medical practice. In the present study we investigated the effect of isoflurane and sevoflurane on rat hepatocytes. MethodsA total of 40 Wistar female rats were used in this study. Animals were divided in groups of 5 rats. Groups IM, SM served as control groups. Groups I1, I2, I3 were used to study isoflurane and S1, S2, S3 for sevoflurane study. They were anesthetized 3 times, for 2h long, at 2 days interval with a concentration of: 1.5% isoflurane (I1, I2, I3) and 2% sevoflurane (S1, S2, S3). The oxygen supply throughout the anesthesia was 1LO2/min. Groups IM, IS, I1, S1 were sacrificed immediately after the last anesthesia. Groups I2, S2 were sacrificed 6h after the last anesthesia, and groups I3, S3, 24h post-anesthesia. Liver samples were harvested to highlight caspase-3 in apoptotic hepatocytes. ResultsFollowing isoflurane administration, there were less than 1% cells in apoptosis highlighted in rat livers from groups IM, I1 and I2. At 24h post-anesthesia (group I3), a small number of apoptotic hepatocytes was highlighted (around 3.23% cells in apoptosis), with a strictly periacinar disposition, randomly distributed in a small number of hepatic lobules. After sevoflurane administration, less than 1% apoptotic hepatocytes were identified at all control moments throughout the study. ConclusionsThe results suggest that the anesthetics do not present a considerable hepatotoxicity. The comparative assessment of the two anesthetics shows that sevoflurane is superior to isoflurane.

Effect of different durations of low-concentration isoflurane anesthesia on expression of NR2B in hippocampus of mice

Objective To investigate the effect of different durations of low-concentration isoflurane anesthesia on the expression of 2B subunits-containing N-methyl-D-aspartate receptors(NR2B)in the hippocampus of mice. Methods Forty C57BL/6 mice, aged 10 weeks, weighing 20-24 g, were randomly divided into 5 groups(n=8 each)using a random number table: control group(group C); 0.7%-1.0% isoflurane inhaled for 30 min group(group I1); 0.7%-1.0% isoflurane inhaled for 2 h group(group I2); 0.7%-1.0% isoflurane inhaled for 4 h group(group I3); 0.7%-1.0% isoflurane inhaled for 6 h group(group I4). Morris water maze test was carried out at 48 h after the end of anesthesia, and the escape latency and frequency of crossing the original platform were recorded.The mice were sacrificed after the end of the test, and the hippocampi were removed for determination of the expression of activated caspase-3 and NR2B(using Western blot analysis). Results Compared with group C, the escape latency was significantly shortened, and the frequency of crossing the original platform was increased in I1 and I2groups, no significant changes were found in the activated caspase-3 expression, and the expression of NR2B was up-regulated in I1, I2 and I3 groups, and the escape latency was prolonged, the frequency of crossing the original platform was decreased, the activated caspase-3 expression was up-regulated, and the expression of NR2B was down-regulated in group I4. Conclusion The mechanism underlying the effect produced by different durations of low-concentration isoflurane anesthesia on the cognitive function is related to the expression of NR2B in the hippocampus of mice. Key words: Isoflurane; Cognition disorders; Receptors, N-methyl-D-aspartate; Hippocampus

Experimental study on contrast-enhanced ultrasound to evaluate testicular microvascular injury

Objective To explore the way of contrast-enhanced ultrasound(CEUS) and quantitative analysis technology to assess testicular microvascular ischemia-reperfusion injury. Methods Twenty-four healthy adult rabbits were randomly divided into the control group and the microvascular mild, moderate, serve ischemic injury group (group Ⅰ, including group Ⅰ1, Ⅰ2, Ⅰ3). The spermatic cord of the control group were threaded but not ligated. The group Ⅰ1, Ⅰ2, Ⅰ3 were reperfused 2 h after 2 h, 4 h, 6 h complete testicular ischemia respectively. The ultrasound contrast angiographic parameters of each group were analyzed by the quantitative analysis techniques, including peak intensity(PI), time to peak(TP), slope, mean transmit time(MTT), DT/2 and area. The levels of plasma vWF, NO and ET-1 were tested after the CEUS. The pathological changes of the ipsilateral testicular were observed by the HE and immunohistochemical staining. Statistical analysis was performed by SPSS13.0 software. Results Preoperativeiy, each parameter of the experimental group and the control group showed no statistical significance (P>0.05). Postoperatively, the PI, slope, area of the group Ⅰ1 increased significantly, while the TP, MTT were prolonged(P<0.05). Contrast time-intensity curve was significantly higher peak and retrusion. The group Ⅰ2′s PI, slope, area increased further, DT/2 was significantly prolonged, but TP significantly reduced(P<0.05). The contrast curve significantly increased, forward and decreased slowly. The contrast curves of the group Ⅰ3 was approximate a straight line. The vWF, NO, ET-1 levels of each experimental group were significantly higher than those in control group (P<0.05), among them, the levels of group Ⅰ2 were the highest(P<0.05). With the aggravation of ischemia, the testicular capillaries expansion, erythrocyte sedimentation, leakage, infiltration of inflammatory cells, MMP-9 expression in vascular basement membrane gradually increased. Conclusions The CEUS and quantitative analysis techniques can effectively evaluate testicular microvascular injury. Key words: Ultrasonography; Microbubbles; Testis; Ischemia; Reperfusion injury

Oxidative Stress Evaluation in Rats Anesthetized with Isoflurane or Sevoflurane

Oxidative stress implies an imbalance between antioxidant production and reactive oxygen species generation. In this experimental study, we aimed to assess the effects of two inhalational anesthetics (isoflurane and sevoflurane) on the oxidative stress enzymes, namely: superoxid dismutase and glutathione peroxidase. Our protocol included 40 Wistar female rats, divided into 8 groups (5 animals per group): IM, I1, I2, I3, SM, S1, S2 and S3. The groups were subdued to: oxygen alone (control groups IM and SM), isoflurane (I1, I2, I3) and sevoflurane anesthesia (S1, S2, S3), 3 times, for 2 hours long, every other day. The supplied oxygen was 1l O 2 /min and the concentration of isoflurane and sevoflurane was 1 minimum alveolar concentration (1 MAC). We harvested blood samples from each group at different moments: IM, SM, I1, S1 - immediately, I2, S2 - 6 hours and I3, S3 - 24 hours after the treatment. We assessed superoxid dismutase and glutathion peroxidase in the red blood cells. Both anesthetics drecreased the enzyme activities: isoflurane in groups I1 and I3, whereas sevoflurane in all experimental groups (S1, S2, S3).

Impact of Isoflurane and Sevoflurane Anesthesia on Kidney Structure and Function in Rats

Various researchers studied the nephrotoxicity of inhalational anesthetics, with contradictory results. We aimed to observe the impact of the repeated isoflurane or sevoflurane anesthesia on kidney structure and function. 40 female rats were used in this study. Animals were divided in 8 groups. Two groups served as control: IM (isoflurane) and SM (sevoflurane), exposed to oxygen alone (1l/min) 3 times, for 2 hours, every other day. Three groups were anesthetized with isoflurane (I1, I2, I3) and the other three (S1, S2, S3) with sevoflurane. The anesthetics were administered three times, for two hours long each, every other day. Rats were sacrificed through cervical dislocation as follows: groups IM, SM, I1, S1 imediately after the last anesthesia, groups I2, S2 – 6 hours post-anesthesia and groups I3, S3 – 24 hours post-anesthesia. Kidney samples were harvested, fixed in 10% buffered formaline, embedded in paraffin, sectioned (5 µm thickness) and stained with Goldner’s trichrome metod. After isoflurane anesthesia, the kidney displays a moderate congestion in the corticomedullary area, which maintains throughout the experimental period. The only changes in animals anesthetized with sevoflurane also appear on the vascular component. The congestion maintains throughout the experimental period in the renal cortex, as well as the corticomedullary area. No other aspects that suggest functional impairment are observed, in any of the experimental groups. Inhalational anesthesia with isoflurane and sevoflurane produces a moderate congestion, without majorly impairing the kidney function.

English

OBJECTIVES: To study the correlation between fetal abdominal subcutaneous fat thickness (FASTT) and actual birth weight. METHODS: Fifty women with normal singleton pregnancy underwent sonography at 37-39weeks of gestation. Subcutaneous fat measurement of fetal abdomen was done at the about 2cm from the site of entry of umbilical vein into the fetal abdomen. It was then correlated with the actual fetal weight. RESULTS: Birth weight was divided into three groups for analytic purposes. Group I-weight less than 10th percentile, Group II-10th to 90th percentile and Group III more than 90th percentile. Subcutaneous fat had a high degree of correlation with actual birth weight. The mean subcutaneous fat thickness varied significantly as in Group I3.7mm, Group II-5.4mm and Group III-6.1mm (p value<0.001)with average fat thickness of newborns having birth weight between 10th-90th percentile was 5.4mm.Conclusion:-Foetal Subcutaneous fat thickness correlates well with actual birth weight and is a useful predictor of foetal growth abnormalities.

Clinicophysiological and haemodynamic effects of fentanyl with xylazine, medetomidine and dexmedetomidine in isoflurane-anaesthetised water buffaloes (&lt;i&gt;Bubalus bubalis&lt;/i&gt;)

The present study was undertaken to investigate the sedative, analgesic and clinical effects of xylazine, medetomidine and dexmedetomidine with fentanyl as pre-anaesthetics in water buffaloes and to compare the dose-sparing effect of xylazine, medetomidine and dexmedetomidine on thiopental for induction and isoflurane for maintenance of anaesthesia in water buffaloes. Six male water buffaloes randomly received intravenous fentanyl (5.0 µg/kg body weight) and xylazine (0.05 mg/kg body weight), fentanyl (5.0 µg/kg body weight) and medetomidine (2.5 µg/kg body weight), fentanyl (5.0 µg/kg body weight) and dexmedetomidine (5.0 µg/kg body weight) at weekly intervals in groups I1, I2 and I3, respectively. After 15 min, the animals were restrained in right lateral recumbency and anaesthesia was induced by 5% thiopental sodium administered intravenously. The intubated animal was connected to the large animal anaesthesia machine and isoflurane in 100% oxygen (5 L/min) was insufflated for 60 min. The treatments were compared by clinicophysiological, haematobiochemical and haemodynamic parameters. Fentanyl-medetomidine and fentanyl-dexmedetomidine produced more cardiovascular depression during the pre-anaesthetic period but less depression of cardio-respiratory dynamics in the post induction and maintenance period. Quicker recovery was recorded in I2 and I3 groups. A lower dose of thiopental was required in group I3 (4.33 mg/kg ± 0.66 mg/kg) than in groups I2 (4.41 mg/kg ± 0.98 mg/kg) and I1 (4.83 mg/kg ± 0.79 mg/kg). The dose of isoflurane was less in group I3 (45.50 mL ± 5.45 mL) than in group I1 and I2 (48.66 mL ± 5.10 mL and 48.00 mL ± 6.38 mL). Better anaesthesia was recorded with fentanyl-dexmedetomidine-thiopental-isoflurane (group I3) than with fentanyl-medetomidine-thiopental-isoflurane (group I2) and fentanyl-xylazine-thiopental-isoflurane (group I1). Fentanyl-medetomidine and fentanyl-dexmedetomidine were better pre-anaesthetic agents in comparison to fentanyl-xylazine for thiopental and isoflurane anaesthesia. Fentanyl-dexmedetomidine-thiopental-isoflurane and fentanyl-medetomidine-thiopental-isoflurane produced effective surgical anaesthesia and were found to be safe, as cardio-pulmonary functions were well preserved during maintenance anaesthesia with no deleterious effect on vital organ functions in water buffaloes.

Hematological and biochemical changes due to short-term oral administration of imidacloprid

Subacute toxicity of repeated (28 day) oral administration of imidacloprid in male White Leghorn (WLH) chicks was assessed. One hundred and twenty-five birds were divided into five groups, with each group containing 25 birds. The birds of group C1 were given no treatment and served as control. Group C2 was administered groundnut oil (1 ml/kg) and served as control (vehicle). Group I1 was given 1/40th of apparent LD50 (ALD50) (1.25 mg/kg), and group I2 was put on 1/30th of ALD50 (1.67 mg/kg), while group I3 received 1/20th of ALD50 (2.5 mg/kg) of imidacloprid suspended in groundnut oil. The blood samples were collected from birds after 14 and 28 days of oral administration and analyzed for hematological and biochemical parameters. The study showed that hematological parameters [hemoglobin (Hb), packed cell volume (PCV), total erythrocyte count (TEC)] remained unaffected except total leukocyte count which was decreased at the highest dose tested only on 28th day of experiment in birds of group I3. Imidacloprid produced hypoglycemia during the entire period of study, which was dose dependent. Imidacloprid treated birds showed significant increase in serum glutamate oxaloacetate transaminase (SGOT) level at 14 and 28 days of experiment, while no significant change in serum glutamate pyruvate transaminase (SGPT), serum total protein, serum total albumin, serum total globulin and serum creatinine was seen.

Characterization of Archaeal Community in Contaminated and Uncontaminated Surface Stream Sediments

Archaeal communities from mercury and uranium-contaminated freshwater stream sediments were characterized and compared to archaeal communities present in an uncontaminated stream located in the vicinity of Oak Ridge, TN, USA. The distribution of the Archaea was determined by pyrosequencing analysis of the V4 region of 16S rRNA amplified from 12 streambed surface sediments. Crenarchaeota comprised 76% of the 1,670 archaeal sequences and the remaining 24% were from Euryarchaeota. Phylogenetic analysis further classified the Crenarchaeota as a Freshwater Group, Miscellaneous Crenarchaeota group, Group I3, Rice Cluster VI and IV, Marine Group I and Marine Benthic Group B; and the Euryarchaeota into Methanomicrobiales, Methanosarcinales, Methanobacteriales, Rice Cluster III, Marine Benthic Group D, Deep Sea Hydrothermal Vent Euryarchaeota 1 and Eury 5. All groups were previously described. Both hydrogen- and acetate-dependent methanogens were found in all samples. Most of the groups (with 60% of the sequences) described in this study were not similar to any cultivated isolates, making it difficult to discern their function in the freshwater microbial community. A significant decrease in the number of sequences, as well as in the diversity of archaeal communities was found in the contaminated sites. The Marine Group I, including the ammonia oxidizer Nitrosopumilus maritimus, was the dominant group in both mercury and uranium/nitrate-contaminated sites. The uranium-contaminated site also contained a high concentration of nitrate, thus Marine Group I may play a role in nitrogen cycle.Electronic supplementary materialThe online version of this article (doi:10.1007/s00248-010-9734-2) contains supplementary material, which is available to authorized users.

Role of protein kinase C in induction of vascular endothelial growth factor secretion by isoflurane in primary cultured rat cardiomyocytes

Objective To investigate the role of protein kinase C (PKC) in induction of vascular endothelial growth factor (VEGF) secretion by isoflurane in primary cultured rat cardiomyocytes. Methods Primary cultured neonatal rat cardiomyocytes were randomly divided into 6 groups ( n = 6 each): control group (group C), 3 different concentration isoflurane groups (group Ⅰ1-3 ), PKC inhibitor calphostin C group (group P), and PKC inhibitor + isoflurane group (group PI). The cells were exposed to 0.7%, 1.4% and 2.1% isoflurane for6 h in group Ⅰ1-3 respectivly. Calphostin C was added to the culture medium with a final concentration of 50 nmol/L in group P. Calphostin C was added to the culture medium with a final concentration of 50 nmol/L, then the cells were exposed to 1.4% isoflurane for 6 h in group PI. VEGF concentrations and expression of PKC isoforms were determined by ELISA and Western blot respectively. Results Compared with group C, the VEGF concentration was significantly increased in group Ⅰ2 and Ⅰ3, and PKCe expression was down-regulated in the cytoplasm while upregulated in the cytomembrane in group Ⅰ2 ( P ＜ 0.01 ), but no significant change was found in the parameters mentioned above in group Ⅰ2 ( P ＞ 0.05). PKCα, PKCδ and PKCζ expression was significantly higher in the cytoplasm than in the cytomembrane in group C and Ⅰ2. VEGF concentrations were gradually increased with the increase in isoflurane concentrations ( P ＜ 0.05). VEGF concentrations were significantly lower in group PI than in Ⅰ2 ( P ＜0.05) .Conclusion Isoflurane induces VEGF secretion in primary cultured rat cardiomyocytes through translocation of PKCe from the cytoplasm to the cytomembrane, suggesting that it is a mechanism of the cardioprotective effects of isoflurane. Key words: Isoflurane; Myocytes, cardiac; Protein kinase C; Vascular endothelial growth factors

Effect of intrathecal injection of ifenprodil on the expression of 2B subunit mRNA of NMDA receptor in spinal cord in a mouse model of bone cancer pain

Objective To investigate the effect of intrathecal injection of ifenprodil on the expression of 2B subunit mRNA of NMDA receptor (NR2B) in spinal cord in a mouse model of bone cancer pain. Methods One hundred and forty male C3H/HeJ mice weighing 20-25 g were randomly divided into 5 groups (n=28 each):group S sham operation; group B bone cancer pain; group I1- ifenprodil 2.5, 5 and 10 μg. Bone cancer pain was performed by intra-right-femur inoculations of osteolytic NCTC 2472 cells in group I1- and B. On the 14 d after inoculations, group I1-3 received intrathecal injection of ifenprodil 2.5, 5 and 10 μg dissolved in 5 μl solvent respectively, while group B and S received intrathecal injection of solvent. Seven mice was selected randomly from each group at 1 d before inoculations, at 1 h before, intrathecal injection of ifenprodil or solvent and at 2, 12 and 24 h after the injection (T1-5) tor determination of mechanical and thermal pain threshold. The mice were decapitated at T2.5 after determination of pain threshold and the L3-5 part of spinal cord was removed for determination of the expression of NR2B mRNA by RT-PCR. Results The mechanical and thermal pain threshold were significantly lower in group B and I1-3(P 0.05), and the expression of NR2B mRNA was significantly higher in group B and I3 while lower in group I2.3 than in group S (P 0.05). The mechanical and thermal pain threshold were significantly higher and the expression of NR2B mRNA was lower in group I3 than in group I2 (P <0.05). Conclusion lntratheeal injection of ifenprodil can attenuate bone cancer pain through blocking NR2B and inhibit hyperalgesia through down-regulating the NR2B mRNA expression in spinal cord. Key words: Piperidines; Receptors, N-methyl-D-aspartate; Spinal cord; Bone neoplasms; Injections, spinal

An in vitro evaluation of prostaglandin E1 and I2 on hypothermic injury to immature myocytes.

The purpose of this study was to evaluate the functional and biochemical effects of Prostaglandin E1 (PGE1) and prostaglandin I2 (PGI2) on cardiac myocytes incubated under hypothermic conditions. Cardiac myocytes were isolated from neonatal rat ventricles and cultured for 4 days with MCDB 107 medium. Following this, 12.5 x 10(5) myocytes/flask were incubated at 4 degrees C for 24 h in media with PGE1, at concentrations of 0 M (group E0), 10(-9) M (group E1), 10(-8) M (group E2), 10(-7) M (group E3), or 10(-6) M (group E4); or with PGI2 at concentrations of 0 M PGI (group I0), 10(-9) M (group I1), 10(-8) M (group 12), 10(-7) M (group I3), or 10(-6) M (group I4). After hypothermic incubation, creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) were measured, and the myocytes were then cultured for 24 h at 37 degrees C to evaluate the recovery of the myocyte beating rate. Of the PGI2 groups, only group I2 recovered significantly more than the control group (group I0), at 47.9 +/- 28.5% (mean +/- SD) of the control, being the beating rate prior to hypothermic incubation, whereas it was 18.1 +/- 9.7% in group I0 (P < 0.025); however, there were no significant differences among the PGE1 groups. Moreover, the release of CPK and LDH was significantly suppressed in group 12 compared to the control, being 57.7 +/- 27.6 mIU/flask (P < 0.05) and 275.1 +/- 83.0 mIU/flask (P < 0.025), respectively, in group I2, and 96.8 +/- 38.3 mIU/flask and 439.6 +/- 147.1 mIU/flask in group I0. Again, no significant differences were observed among the PGE1 groups. In conclusion, PGI2 was found to have a direct cytoprotective effect on immature myocytes which suggests that PGI2 may promote cardiac preservation in the neonatal period.