Changes in placental permeability to corticosterone and estradiol-17β toward the end of gestation in the rat

Summary Radioactivity in the fetal plasma 1 h after maternal injection of¹⁴C-4-corticosterone or¹⁴C-4-estradiol-17 on day 21 of gestation was markedly higher than that 1 h after injection on day 22. Radioactivity in the maternal plasma was not different on these 2 days. The results suggest that the placental permeability to steroids from the mother to the fetus declines toward the end of gestation in the rat.Acknowledgment. We are indebted to Professor Tatsuo Imori (Department of Veterinary Surgery, College of Agriculture, University of Osaka Prefecture) for his valuable suggestions during the course of this study.     

The role of maternal parathyroids and vitamin D3 metabolites in fetal growth and the deposition of glycogen reserves in the maternal and fetal liver in rats]

Thyro-parathyroidectomy of pregnant Rats at 12.5 days of gestation decreased maternal liver glycogen on 21.5 days of gestation and fetal weight as well as fetal liver glycogen stores. The graft of one parathyroid gland or the injection of 1 alpha-hydroxycholecalciferol in these thyro-parathyroidectomized mothers increased their liver glycogen stores at 21.5 days of gestation. These treatments also markedly increased both fetal weight and fetal liver glycogen stores. It was concluded that maternal 1,25-dihydorxycholecalciferol, which is synthesized under the control of parathyroid hormone secretion, controls fetal growth and liver glycogen stores. The mechanism of these effects (direct or indirect) requires further investigations.     

In vivo incorporation of 14C-phenylalanine into ascidian tunichrome.

Ascidia ceratodes exposed to 14C-phenylalanine in the surrounding seawater incorporates the radiolabel into newly biosynthesized tunichrome molecules. Radioactivity can be detected in tunichrome extracted from circulating blood cells within one day following initial exposure to the radiolabel; weak activity (less than or equal to 4 microCi/mol tunichrome = 22 nmol phenylalanine/mol tunichrome) is detected in 1 to 10 days; significantly higher amounts of radiolabel (57 microCi/mol tunichrome = 318 nmol phenylalanine/mol tunichrome) appear 20 days after seawater exposure. Therefore, phenylalanine can function as a precursor in the biosynthesis of tunichrome.     

Maternal stress alters monoamine metabolites in fetal and neonatal rat brain

Heat-restraint stress given rats during the last week of gestation significantly altered dopaminergic dihydroxyphenylacetic acid and homovanillic acid (DOPAC and HVA) and noradrenergic 3-methoxy-4-hydroxy-phenyl-ethylene glycol (MOPEG) forebrain-hypothalamic monoamine (MA) metabolites in female offspring. On gestational day 21, HVA and MOPEG were significantly higher and lower, and on postnatal day 1 all were higher. There were virtually no differences in brain MA concentrations in males. Thus MA metabolic concentrations differ in fetal-neonatal forebrain-hypothalamus as a function of sex differences and maternal stress.     

Maternal stress alters monoamine metabolites in fetal and neonatal rat brain

Summary Heat-restraint stress given rats during the last week of gestation significantly altered dopaminergic dihydroxyphenylacetic acid and homovanillic acid (DOPAC and HVA) and noradrenergic 3-methoxy-4-hydroxy-phenyl-ethylene glycol (MOPEG) forebrain-hypothalamic monoamine (MA) metabolites in female offspring. On gestational day 21, HVA and MOPEG were significantly higher and lower, and on postnatal day 1 all were higher. There were virtually no differences in brain MA concentrations in males. Thus MA metabolic concentrations differ in fetal-neonatal forebrain-hypothalamus as a function of sex differences and maternal stress.     

Protein anabolism in endometrium and myometrium during the growth of induced deciduoma in rats

Summary Protein anabolism in the endometrium and myometrium was studied during the growth of induced deciduoma in terms of incorporation of [¹⁴C]-leucine into proteins. The data show that the specific activity of the proteins was highest 2 days after decidualisation. Protein synthesis in the endometrium studied on that day as a function of time after injection of the labelled amino acid showed a steady increase during the first 2 h. Cycloheximide (2 mg/kg b.wt) administration produced nearly 95% inhibition of protein synthesis in endometrium as well as in myometrium.     

Placental permeability of arsenate ion during early embryogenesis in the hamster

Summary Sodium arsenate crosses the placental barrier in pregnant Syrian hamsters following injection in teratogenic or tracer doses on the 8th day of gestation.This work was supported by USPHS grant ES-00697.     

Inhibitory effects of LHRH on ovarian LH receptors in rats]

The administration of LHRH or of its analog [D-Ala6, des-Gly-NH10(2)] LHRH ethylamide to the female rat on day 10 of gestation resulted in termination of pregnancy and in a marked decrease in ovarian LH receptors and plasma progesterone level. Asingle injection of either compound during diestrus I also led to a decrease in LH receptors. These data demonstrate the high sensitivity of the control of ovarian LH receptors by circulating gonadotrophins and suggest that the contraceptive action of pre- and postcoitally administered LHRH is mediated by negative control of LH receptors.     

Cell kinetic studies in the epidermis of the mouse. I. Changes in labeling index with time after tritiated thymidine administration

The changes in the labeling index (LI) with time after a single injection of tritiated thymidine (3HTdR) at each of 4 different times of the day have been studied. Slight differences occur in the shape of these LI curves, (e.g. in the timing of the peaks) depending on the time of day when the initial injection was given. Thus, the time of day influences not only the number of cells in DNA synthesis but also determines the subsequent behavior of the labeled cells. The curves show 3 distinct peaks from which estimates of the cell cycle time can be made. The technique permits the cell cycle time to be estimated. From the data as a whole a minimum cell cycle time of 90 h for basal cells in the epidermis on the back of a mouse is obtained. The technique also provides estimates for the duration of S + G2 + M which varies depending on the time of day that the label is given. The LI curves can best be understood if the basal layer is assumed to contain 2 cell populations with differing cell cycle times; one having a long cell cycle (about 180 h) but short S-phase and containing the stem cells, the other having a short cell cycle (about 90 h) and a long S-phase duration and consisting of transit cells.     

Melatonin in the plasma of growing sheep subjected to short and skeleton long photoperiods

Summary The levels of melatonin in plasma were measured at hourly intervals for 24 h in 8 sheep, 4 under 8L:16D (short day) and 4 under 7L:10D:1L:6D (skeleton long day) after 38 days of exposure. Mean concentrations did not differ significantly between treatments (52 pg/ml under short days; 91 pg/ml for skeleton long days), but the levels were more stable during 24 h in the SD treatment. Under skeleton long days there were 3 peaks during the 10D scotophase, with low levels during the 6D scotophase and the 7L photophase.     

Mastocytosis in suckling mice.

In suckling mice injected intraperitoneally with mitomycin C on the 1st to 5th day after birth and sacrificed in the course of 24 or 48 h after injection, mastocytosis occurred in the oral mucosa membrane, skin of the trunk or extremities and bone marrow of extremities.     

Mastocytosis in suckling mice

Summary In suckling mice injected intraperitoneally with mitomycin C on the 1st to 5th day after birth and sacrificed in the course of 24 or 48 h after injection, mastocytosis occurred in the oral mucosa membrane, skin of the trunk or extremities and bone marrow of extremities.     

Zur Biosynthese des Cantharidins. I

Summary In contrast to the female, the adult males ofLytta vesicatoria (Coleopt. Meloidae) produced radioactive cantharidine on injection with¹⁴C-1-acetate and¹⁴C-2-mevalonate solutions. A partial degradation of the cantharidine showed that in the acetate experiment approximately of the activity occurred at C atoms 2 + 3 whereas with mevalonate approximately of the activity was at C atoms 8 + 9 and at C atoms 10 + 11. These results show that cantharidine is not formed by a tail to tail linkage of 2 isoprene units.

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Wir danken dem Schweizerischen Nationalfonds zur Förderung der wissenschaftlichen Forschung für die Unterstützung dieser Arbeit, Herrn Dr.J. Würsch (Physikalisch-chemische Abteilung der Firma F. Hoffmann-La Roche & Co. AG, Basel) für¹⁴C-2-Mevalolacton und unserer mikroanalytischen Abteilung (LeitungH. Frohofer) für die Aktivitätsbestimmungen.     

Sexual differences in the development of plasma thyroxine levels in the embryo and young chick]

Plasma thyroxine (T4) levels were separately ascertained in male and female embryo and young chicken from the 12th day of incubation till the 4th day after hatching by the thyroxine binding globulin technique. In both sexes, plasma T4 reach a peak the 20th day of incubation, but values are significantly higher in females. A sharp decrease occurred thereafter, plasma T4 tending toward adult values the 4th day after hatching.     

Intra-brain microinjection of human mesenchymal stem cells decreases allodynia in neuropathic mice

Neuropathic pain is a very complex disease, involving several molecular pathways. Current available drugs are usually not acting on the several mechanisms underlying the generation and propagation of pain. We used spared nerve injury model of neuropathic pain to assess the possible use of human mesenchymal stem cells (hMSCs) as anti-neuropathic tool. Human MSCs were transplanted in the mouse lateral cerebral ventricle. Stem cells injection was performed 4 days after sciatic nerve surgery. Neuropathic mice were monitored 7, 10, 14, 17, and 21 days after surgery. hMSCs were able to reduce pain-like behaviors, such as mechanical allodynia and thermal hyperalgesia, once transplanted in cerebral ventricle. Anti-nociceptive effect was detectable from day 10 after surgery (6 days post cell injection). Human MSCs reduced the mRNA levels of the pro-inflammatory interleukin IL-1β mouse gene, as well as the neural β-galactosidase over-activation in prefrontal cortex of SNI mice. Transplanted hMSCs were able to reduce astrocytic and microglial cell activation.     

Spontaneous morphine withdrawal from the rat spinal cord

A characteristic and reproducible sign of narcotic withdrawal is the naloxone induced increase in arterial pressure. In morphine-dependent rats allowed to undergo spontaneous withdrawal (6-24 h) and then transected at the spinal C-1 level, arterial pressure was maintained at a significantly higher level than either spinal-transected nondependent controls or morphine-dependent, spinal-transected rats pithed from C-1 to L-4. These findings indicate that the morphine-dependent spinal cord, independent of supraspinal influences, is able to exhibit an autonomic component of spontaneous withdrawal.     

Teratogene Wirkung von 1-Phenyl-3,3-dimethyl-triazen,Erzeugung von Gaumenspalten bei BD-Ratten

Summary 1-Phenyl-3, 3-dimethyl-triazene and its monomethyl-derivative, when given as single s.c. injection of 75 mg/kg b.w. to pregnant rats on the 15th day of gestation, proved to be powerful cleft palate teratogens.     

Progesterone formation and metabolism by rabbit placenta in vitro

4-¹⁴C-Progesterone and 4-¹⁴C-pregnenolone are metabolized in vitro by rabbit placenta, at day 15 and 28 of gestation, exclusively to compounds reduced in ring A (5) and at carbon 3 and 20.     

Alopecia induced in young mice by exposure to excess dietary zinc

Second generation mice were exposed to normal (50 ppm, Group I) or excess (2000 ppm, Group II) zinc in the maternal diet during gestation and lactation, then weaned and continued on the mother's diet until sacrifice at 8 weeks. Tibia zinc reflected dietary intake. Group II had reduced plasma copper, body weight, and hematocrit; the second coat of hair appeared late and was lighter in color than Group I, possibly as an effect of copper and pigmentation development and hair growth.     

The involvement of serotonin in induced ovulation in the immature rat.

In pregnant mare's serum gonadotropin (PMS) treated immature rats the cortex, cerebellum, caudate nucleus and hypothalamus were isolated and analyzed for their serotonin (5-HT) content at 6-h intervals for 72 h. Results showed a general trend of significant variation occurring in days 1 and 3 after PMS injection with no major variations observed on the second day. The results obtained suggest a possible involvement of 5-HT in the control of ovulation.