Narrowing abdominal aorta and vein is a simple and useful method for preparing a mice model of gestational hypertension.

Hypertensive disorder of pregnancy (HDP) is a major cause of maternal morbidity and mortality, fetal growth restriction (FGR), and premature delivery. Soluble fms-like tyrosine kinase-1 (sFLT-1) is significantly elevated in pre-eclamptic women. Making animal models of hypertensive pregnancy is costly and requires advanced equipment. We established a gestational hypertension (GH), one of the HDP subtypes, mouse model by narrowing the abdominal aorta and vein together with a medical drip tube on day 10.5 of gestation. Systolic and diastolic blood pressure on day 18.5 of gestation in the narrowed aorta and vein (NAV) group were significantly higher than those in the control group. Fetal weight decreased in the NAV group. Serum sFLT-1 was significantly increased in the NAV group on day 18.5 of gestation compared to the control group. After delivery, blood pressure and serum sFLT-1 level did not differ between the NAV and the control groups. These parameters normalized postpartum. We established a novel GH mouse model through an easy operative procedure using a simple device. In this NAV model, blood pressure and serum sFLT-1 level were increased on day 18.5 of gestation, and normalized promptly after delivery. The mouse model mimics human GH, and is suitable for the development of other treatments.

Drug Repositioning for Preeclampsia Therapeutics by In Vitro Screening: Phosphodiesterase-5 Inhibitor Vardenafil Restores Endothelial Dysfunction via Induction of Placental Growth Factor.

We screened a library of 528 approved drugs to identify candidate compounds with therapeutic potential as preeclampsia treatments via their proangiogenic properties. Using human umbilical vein endothelial cells (HUVECs), we assessed whether the screened drugs induced placental growth factor (PIGF) and restored damaged endothelial cell function. Enzyme-linked immunosorbent assays (ELISAs) were carried out to measure levels of PlGF in conditioned media treated with each drug (100 µmol/L) in the drug library. Tube formation assays were performed using HUVECs to evaluate the angiogenic effects of drugs that induced PlGF. We also performed ELISA, quantitative reverse transcription polymerase chain reaction, and tube formation assays after treatment with a range of concentrations of the candidate drug. Of the drugs that induced PlGF, vardenafil was the only compound that significantly facilitated tube formation in comparison with the control cells (P < .01). Treatment with vardenafil at concentrations of 50, 100, and 250 µmol/L increased expression of PlGF in a dose-dependent manner. Vardenafil (250 µmol/L) significantly improved tube formation which was inhibited in the presence of soluble fms-like tyrosine kinase 1 (100 ng/mL) and/or soluble endoglin (100 ng/mL). Production of PlGF from HUVECs in the presence of sera derived from patients with preeclampsia was significantly elevated by administration of vardenafil (250 µmol/L). By assessing drug repositioning through screening a library of approved drugs, we identified vardenafil as a potential protective agent against preeclampsia. The therapeutic mechanism of vardenafil may involve inhibition of the systemic maternal antiangiogenic state that leads to preeclampsia, in addition to its vasodilating effect. As concentrations used are high and unlikely to be useful clinically, further work is needed before testing it in humans.

Importance of optimal local uterine blood flow for implantation.

AIMS: The aim of this study was to determine whether uterine blood flow is an effective parameter to anticipate uterine receptivity. MATERIAL AND METHODS: The local uterine blood flow was measured in the endometrium and on the outside of the uterus in mice during the early stage of pregnancy and an implantation failure mouse model using transient and local suppression of signal transducer and activator of transcription-3 activity during implantation. RESULTS: The local uterine blood flow was dramatically increased after mating and was decreased towards the time of implantation. The local uterine blood flow at 2.5 days post-coitus in signal transducer and activator of transcription-3 decoy transferred mice was significantly higher than in control mice. However, the range of individual values was too wide to find a cut-off point. CONCLUSIONS: It is necessary to decrease local uterine blood flow after ovulation to prepare the opening implantation window. The optimal local uterine blood flow is regulated by time events during pregnancy. The range of individual values of uterine blood flow is wide using a laser Doppler blood flow meter. This parameter itself may not be an appropriate parameter to evaluate the prospect of uterine receptivity.

Hypoxic preconditioning increases triiodothyronine (T3) level in the developing rat brain.

Neonatal hypoxic-ischemic encephalopathy (HIE) is one of the major causes of neurodegeneration and mortality in the neonatal period. Although hypoxic preconditioning (HPC) provided strong neuroprotection against HIE in an animal model, the mechanism underlying this effect is not fully understood especially in the immature brain. Here, we investigated whether thyroid hormones (THs), especially triiodothyronine (T3), which are essential during normal brain development, contribute to the neuroprotective mechanisms of HPC by using an established model of HPC in neonatal rats. HPC treatment (8% O2 for 2.5h at 37°C) was performed in immature rats at postnatal day 6 (P6). Subsequently, we investigated the levels of THs, TH receptors (TRs) and type 2 and 3 deiodinase (D2 and D3) mRNA, and glutamate transporter 1 (GLT1) at 24h after HPC treatment, and myelin basic protein (MBP) at 6, 12 and 24h after HPC treatment. The HIE procedure was performed at 24h after HPC, and the neuroprotective effect of HPC was assessed via microtubule-associated protein 2 (MAP2) and MBP immunohistochemical staining at 14 days after HIE (P21). HPC treatment afforded marked neuroprotection at 14 days after HIE. The local level of T3 was upregulated 24h after HPC treatment in the developing rat brain, probably via the upregulation of D2. In addition, the expression of MBP and GLT1, which are the downstream protein of T3, were significantly increased 24h after HPC treatment. The present study indicates that thyroid hormones and their associated molecules may be involved in neuroprotective mechanisms of HPC during the developmental period.

Ceftriaxone preconditioning confers neuroprotection in neonatal rats through glutamate transporter 1 upregulation.

OBJECTIVE: This study investigated the hypothesis that ceftriaxone preconditioning ameliorates brain damage in neonatal animals through glutamate transporter 1 (GLT-1) upregulation. STUDY DESIGN: Sprague Dawley rats were pretreated with ceftriaxone, erythromycin, minocycline, or saline for 5 consecutive days starting from postnatal day 2 (P2), and GLT-1/glutamate-aspartate transporter (GLAST) messenger RNA (mRNA) and protein levels were examined in the P7 brains. After ceftriaxone or saline preconditioning, the P7 rats underwent hypoxic-ischemic (H-I) procedure or sham operation. One week after the procedure (P14), hematoxylin-eosin staining, microtubule-associated protein 2 (MAP-2) immunostaining, and transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) assay were used to examine neuronal damage and possible neurotoxicity. RESULTS: Repeated ceftriaxone injections significantly increased GLT-1 mRNA and protein levels but not GLAST. Following such treatment and H-I procedure, the MAP-2-positive area increased and TUNEL-positive cells decreased. CONCLUSION: Antenatal ceftriaxone may help to provide neuroprotection in the immature brain and become a new prophylactic strategy to reduce neonatal encephalopathy in clinical perinatal medicine.

Effect of hypothermia on motor function of adult rats after neonatal hyperthermic hypoxic-ischemic brain insult.

Regarding therapeutic hypothermia for human neonatal hyperthermic hypoxic-ischemic encephalopathy (HIE), we investigated the motor function of a neonatal hyperthermic HIE rat model, and also performed systemic hypothermia using the model. Forty-two neonatal Wistar rats at 7-days-old were used in this study. The left common carotid artery of 34 neonatal rats was ligated under isoflurane anesthesia. We also established a sham group (S group, n = 8). After 1-h recovery, all rats were exposed to 8% oxygen at an ambient temperature (T (a)) of 40 degrees C for 15 min. Following insult, 16 rats were placed in a chamber at a T (a) of 30 degrees C (H group) and the other 18 rats at a T (a) of 37 degrees C after arterial ligation (N group), and all rats in the S group were placed in a chamber at a T (a) of 37 degrees C for 12 h. A Rota-Rod test was performed involving all rats at 8 weeks old. The rod was rotated at 5, 5, and 7 rpm on three consecutive days, respectively. Rats in the N group stayed on the rotating rod for a significantly shorter period than those in S and H groups only on the second day of measurement. The width of the insulted hemisphere in N group rats was significantly smaller than those in S and H groups. There was no significant correlation between S and H groups regarding the motor function and anatomy. These results suggest that neonatal hyperthermic hypoxic-ischemic insult impairs the motor function, which may be rescued by systemic hypothermia after insult.

Effect of temperature on the development of free-living stages of Strongyloides ratti.

In the genus Strongyloides, larval development external to the host is known to be markedly affected by a variety of environmental factors. This investigation focuses on the effect of temperature on Strongyloides ratti. Low temperature (15 degrees C) was shown to favor direct development, producing infective larvae, while high temperature (25 degrees C) favored indirect development, producing free-living females and males. Different courses of development were brought about by either a 16-h temperature stimulus at 15 degrees C or a 6-h temperature stimulus at 25 degrees C. Moreover, eggs were not susceptible to the cold-temperature stimulus of 15 degrees C, while newly hatched larvae were. The results indicate that the developmental course of S. ratti larvae external to the host is determined at a relatively early stage before the first molt.