Indirect Effect of X-Irradiation on Embryonic Development: Utilization of High Doses of Maternal Irradiation on the First Day of Gestation

1968 ◽  
Vol 36 (3) ◽  
pp. 563 ◽  
Author(s):  
Robert L. Brent ◽  
Booker T. Bolden
Keyword(s):  
Embryonic Development ◽  
Indirect Effect ◽  
X Irradiation ◽  
High Doses

High doses of lipid-core nanocapsules do not affect bovine embryonic development in vitro

2017 ◽  
Vol 45 ◽  
pp. 194-201 ◽  
Author(s):  
Caroline G. Lucas ◽  
Mariana H. Remião ◽  
Franciele A. Bruinsmann ◽  
Isadora A.R. Lopes ◽  
Morgana A. Borges ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Lipid Core ◽  
Development In Vitro ◽  
High Doses

Sedimentation von nukleoiden aus thymus- und milzzellen der ratte nach ganzkörper-röntgenbestrahlung / Sedimentation of nucleoids from thymic and splenic cells of the rat following total-body x-irradiation

1988 ◽  
Vol 43 (1-2) ◽  
pp. 126-132 ◽  
Author(s):  
Karlheinz Tempel ◽  
Rüdiger Heinzelmann
Keyword(s):  
Sedimentation Rate ◽  
Dna Lesions ◽  
Proteinase K ◽  
Splenic Cells ◽  
X Irradiation ◽  
High Doses ◽  
Total Body ◽  
Enzymatic Changes ◽  
In Vivo Effects

The sedimentation of nucleoids from thymic and splenic cells of rats was tested following totalbody X-irradiation (TBI) with doses ranging from 24 to 1520 cGy. The principal results may be summarized as follows: 1) The nucleoid sedimentation of the cells was reduced immediately after TBI with doses of ≥ 760 cGy. In the following postirradiation period, an enhancement of sedimentation rate has been observed which could be neutralized by addition of proteinase K to the nucleoid preparation. 2) When nucleoids were prepared 6 h after TBI with doses ≥ 190 cGy, beside the main nucleoid band a smaller nucleoid fraction appeared in the ethidium bromide containing saccharose gradient. This fraction was of less sedimentability than the main nucleoid peak and could not be distinguished from pure, high molecular DNA. - From the present results it is suggested that the reduction of the nucleoid sedimentation immediately following high doses of TBI is the result of primary (non-repaired) DNA lesions whereas the changes detectable some hours later are due to the secondary enzymatic changes connected with the interphase death of the cells. With respect to the detection of in vivo effects of X-irradiation, the nucleoid sedimentation has to be regarded much less sensitive than some biochemical and/or cytomorphological methods

scholarly journals Dose-response effects of equine chorionic gonadotrophin (eCG) and human chorionic gonadotrophin (hCG) on early embryonic development and viable pregnancy rate in rats

Reproduction ◽  
2001 ◽  
pp. 283-287 ◽  
Author(s):  
CF Tain ◽  
HH Goh ◽  
SC Ng
Keyword(s):  
Embryonic Development ◽  
Pregnancy Rate ◽  
Dose Response ◽  
Early Embryo ◽  
Chorionic Gonadotrophin ◽  
Early Embryonic Development ◽  
Embryo Yield ◽  
Female Wistar Rats ◽  
High Doses

The present study examined the dose-response effects of eCG treatment alone and in combination with various doses of hCG on early embryonic development in vivo and viable pregnancy rate in rats. Mated female Wistar rats were treated with eCG alone (0, 10, 20 or 40 iu), or with 20 iu eCG in combination with various doses of hCG (10, 20, 40 or 80 iu) administered 48 h later. The animals were killed on days 2, 3, 4, 5 or 14 of pregnancy and the numbers of embryos and fetuses recovered were scored. All rats treated with 0 or 10 iu eCG were pregnant. The pregnancy rate was reduced from 62.5% on day 2 to 25% on day 14 and from 31% on day 2 to 10% on day 14 in the groups treated with 20 and 40 iu eCG, respectively. The reduction in pregnancy rate induced by 20 iu eCG was negated by the increasing doses of hCG used. A 100% pregnancy rate was noted on days 2 and 3 in the groups treated with doses of hCG between 10 and 80 iu and from day 2 to day 4 in the groups treated with doses of hCG between 20 and 80 iu. However, a higher viable pregnancy rate was observed only in the group treated with 10 iu hCG compared with the group treated with 20 iu eCG and 0 iu hCG. These results imply that hyperstimulation of rats with high doses of eCG compromises pregnancy rate and markedly reduces litter size and that the addition of hCG is required for complete ovulation, which results in higher embryo yield and a delay in early embryo demise.

Desoxyribonucleasen in Mäusenieren unter dem Einfluß von Folsäure / On the Action of Folic Acid on Deoxyribonucleases of Mouse Kidney

1971 ◽  
Vol 26 (6) ◽  
pp. 589-594 ◽  
Author(s):  
K. Tempel
Keyword(s):  
Folic Acid ◽  
Dna Synthesis ◽  
Extreme Values ◽  
Dnase I ◽  
Dnase Ii ◽  
X Irradiation ◽  
Acid Deoxyribonuclease ◽  
High Doses ◽  
Dose Dependent

The behaviour of the in vitro-activities of an alkaline and an acid deoxyribonuclease (DNase I and II, resp.), and of an inhibitor of DNase I of the kidney of mice, as well as of the DNA- and protein-content of kidneys and thymus, was studied in about 500 mice 4 hours to 21 days after exposure to folic acid in doses of 60 — 180 mg/kg body-weight.The most important results can be summarized af follows:1. Activity of DNase I decreased and activities of DNase II and of a DNase I-inhibitor increased under the influence of high doses of folic acid. Significant effects were observed 16 — 24 hours after folic acid-injections. Extreme values (80% decrease [DNase I], 180% increase [DNase II, DNase I-inhibitor]) were reached after 2 and 4 days and were dose-dependent. Control values reappeared within 1 — 3 weeks.2. Protein- and DNA-content of the thymus behaved very similarly to DNase I-activity of the kidney.3. The increase of the DNase II-activity of the kidney under the influence of folic acid resulted from enzyme induction. As to the behaviour of DNase I loss of enzyme out of damaged cells and the induction of a DNase I-inhibitor in the kidney must be taken into account.4. In many systems DNase I may control DNA-synthesis. Preliminary studies on the behaviour of folic acid-induced reaction of the kidney, when inhibited by X-irradiation, Actinomycin D, Actidione, or poly (vinylsulfate), suggest that DNase I-inhibitor plays a certain role in combining protein- and DNA-synthesis by inhibiting DNase I.

Indirect Effect of X-Irradiation on I131 Uptake in Chick Embryos.

1959 ◽  
Vol 101 (2) ◽  
pp. 390-391 ◽  
Author(s):  
F. T. Brayer ◽  
S. R. Glasser
Keyword(s):  
Indirect Effect ◽  
Chick Embryos ◽  
X Irradiation

Microcirculatory effects of whole-body X-irradiation and radiomimetic procedures

1965 ◽  
Vol 208 (3) ◽  
pp. 492-498 ◽  
Author(s):  
Benjamin W. Zweifach ◽  
Evelyn Kivy-Rosenberg
Keyword(s):  
Endothelial Cells ◽  
Nitrogen Mustard ◽  
Whole Body ◽  
Disruptive Effect ◽  
X Rays ◽  
The Status ◽  
X Irradiation ◽  
Vascular Beds ◽  
High Doses ◽  
Capillary Walls

Whole-body X-irradiation (WBR) was administered to young adult, unanesthetized rats. Terminal vascular beds of the exteriorized mesocecum of these rats (most of which had received relatively high doses of X-rays) were observed (under anesthesia) at selected periods between 1 hr and 48 days postirradiation. Thirteen experimental categories were utilized to determine the status of reactivity and of the microvascular barrier. These included topical application of epinephrine, norepinephrine, histamine, and Versene; and injection of heparin, cortisone, nitrogen mustard, bacterial endotoxin, and carbon. Results indicate that by the 3rd–4th day after WBR, response of terminal arterioles and precapillaries to epinephrine and norepinephrine are exaggerated and by the 2nd week, activity is up tenfold over threshold levels. With regard to venular and capillary walls, Versene had a dramatic disruptive effect. The character of the lesion suggests that it is due to an undermining and weakening of the basement membrane, and/or forces which hold the endothelial cells together. There is no evidence, however, that the endothelial cell has been damaged.

Effects of 4-hydroxyandrostenedione and hyperstimulation with pregnant mare serum gonadotrophin on early embryonic development in rats

2001 ◽  
Vol 79 (9) ◽  
pp. 744-753 ◽  
Author(s):  
Terry Y.Y Tong ◽  
Victor H.H Goh
Keyword(s):  
Embryonic Development ◽  
Early Embryonic Development ◽  
Female Rats ◽  
High Dose ◽  
Negative Effects ◽  
Embryo Survival ◽  
High Doses ◽  
Higher Doses ◽  
Pregnant Mare Serum Gonadotrophin

A possible role of high oestradiol levels in mediating the adverse effects of hyperstimulation with pregnant mare serum gonadotrophin (PMSG) on early embryonic development in the rat was investigated using an aromatase inhibitor, 4-hydroxyandrostenedione (4-OHA), to inhibit endogenous oestradiol production. Three experiments were conducted in this study. In the first, varying doses of 4-OHA were administered either concurrently with human chorionic gonadotropin (hCG) to pro-oestrus female rats hyperstimulated at early di-oestrus stage with 20 IU PMSG or alone into nonhyperstimulated pro-oestrus females. At high doses of 1000, 2000, or 5000 µg/rat, 4-OHA substantially improved the survival of embryos in hyperstimulated females, while low doses of 100 and 500 µg/rat were ineffective. The protective effect of 4-OHA on embryo count was optimum at 2000 µg. When administered alone, only the highest dose of 5000 µg/rat 4-OHA increased embryo count. In the second experiment, higher doses of PMSG were studied (30 or 40 IU), with or without 5000 µg/rat 4-OHA given at the time of hCG injection. PMSG proved to be more detrimental with increasing dose, and 5000 µg/rat 4-OHA was able to rescue embryos from death in the 30, but not 40, PMSG group. In the third experiment, the influence of the timing of 4-OHA treatment on its ability to improve the embryo count in hyperstimulated females was examined by introducing 4-OHA 24 h earlier, rather than at the time of hCG treatment. The results showed the importance of timing of 4-OHA administration, as 5000 µg/rat 4-OHA was able to restore embryo survival in the 40 PMSG hyperstimulated group only when it was administered 24 h before hCG injection. Together, these results highlighted that 4-OHA, when administered at the appropriate time and dose, could reverse the negative effects of hyperstimulation from PMSG on early embryonic development. This may be due to its potent aromatase inhibiting properties that lead to the suppression of oestrogen production, thereby alleviating the supraphysiological level of oestradiol, which is typically present in PMSG-treated females. Interestingly, 4-OHA treatment on its own was able to positively influence embryo count when given at a high dose of 5000 µg/rat, and this may be associated with its weak androgenic properties. In conclusion, this study supports the hypothesis that excessive oestradiol is responsible for the negative effects of hyperstimulation with PMSG on early embryonic development.Key words: 4-hydroxyandrostenedione, embryonic development, PMSG, rat.

Sign in / Sign up

Export Citation Format

Share Document