Changes induces by haloperidol (antidepressant drug) on the developing retina of the chick embryo

Morphological and histological studies were done on the retina of chick embryos of 6th, 10th and 16th days of incubation by a single dose of haloperidol (0.25 mg/egg), injected on day zero and 5 of incubation. To get an idea about the extent of the teratogenic effect of this drug on the development retina. Sign of malformation in the chick embryo after administration of haloperidol were seen as absent of the ear vesicles, eyes or decreased size of them. Retardation of growth of the retina at 6th, 10th and 16th days treated chick embryo were observed as evidenced of reduction of the size of the retina, associated with sign of degeneration of the retina cells.

Conclusion

The injection of haloperidol drug give rise to several side effects as retardation of growth and degeneration of the cells. The decrease of the thickness of the layers and less density of the cells was related to direct effect of the drug on the cells of this organ. Also on the DNA formation and on the retardation of cellular mitotic activates, therefore the retina appeared decrease in thickness and less cell density with degeneration its cells.     

Teratogenic effect of the cholesterol synthesis inhibitor AY 9944 on rat embryos in vitro.

AY 9944 [trans-1,4-bis(2-chlorobenzylaminomethyl) cyclohexane dihydrochloride] is an amphiphilic cationic molecule. This chemical is an established inhibitor of cholesterol synthesis and is teratogenic in rats. The mechanisms of this teratogenicity remain to be clarified. This study used cultured rat whole embryos to ascertain whether AY 9944 had a direct effect on embryos, or whether its action was indirect, via the maternal cholesterol metabolism. Four experimental conditions were investigated: (A) controls; (B) 10 day untreated embryos were cultured in serum of treated rats; (C) 10 day untreated embryos were cultured in serum containing added AY 9944 (0-1,000 micrograms/ml); and (D) 10 day embryos from females treated on day 4 of gestation were cultured in normal serum. In group B there was no growth retardation; some slight nonspecific abnormalities were not significant. In group C, direct addition of AY 9944 to culture medium retarded growth and differentiation in a dose-dependent manner. No malformation was observed, but histological examinations showed numerous areas of cell necrosis, especially in the CNS. In group D, not only was growth retardation observed, but also characteristic malformations of AY 9944 teratogenesis, including pituitary agenesis. These results show that AY 9944 teratogenicity is initiated prior to day 10.     

Study of nucleic acid synthesis in rat embryos in relation to phase-specific characteristics of teratogenic effect of chloridine]

The maximal rate of incorporation of 32P-phosphate, 14C-formate and 14C-thymidine in DNA was recorded on the 13th day of development in the rat embryos and that of 14C-formate and 32P-phosphate in RNA and nucleotides of the acid-soluble fraction on the 12th day. The maximal incorporation of 14C-formate was recorded later: on the 15-16th days. Chloridin inhibited the incorporation of 14C-formate in DNA at all developmental stages, irrespective of the sensitivity of embryos to its teratogenic effect. The period of the maximal rate of DNA synthesis coincides with that of highest teratogenic activity of the drug. A suggestion is put forward to the effect that quantitative differences in the intensity of DNA synthesis at different stages of organgenesis provide one of the main causes of differential sensitivity of embryos to the teratogenic effect of inhibitors of nucleic acid synthesis.     

Vertical development of the secondary palate in hamster embryos following exposure to 6-mercaptopurine

Cellular aspects of vertical development of the secondary palate were examined in control and 6-mercaptopurine (6MP)-treated hamster embryos. Cross-sectional area of the palatal shelf was measured and the numbers of both epithelial and mesenchymal cells counted. Also, in 6MP-treated palates the damaged mesenchymal cells, characterized by the presence of dense bodies, were counted. DNA synthesis in both control and treated fetuses was measured by 3H-thymidine incorporation. The results indicated that both the shelf area and cell numbers increased with age in control and 6MP-treated palates. However, in controls the mesenchymal cell density and DNA synthesis showed two peaks that were absent following 6MP treatment. Unlike controls, in treated embryos the damage to mesenchymal cells became increasingly pronounced between days 10:00 and 10:12 but subsided by day 11:00 of gestation. It is suggested that a major force in the development of the initial primordia and early vertical development of the palatal shelf may be provided by a spurt of DNA synthesis in the mesenchymal cells resulting in their increased number. After 6MP treatment, depression of DNA synthesis and consequent reduction in the mesenchymal cell number and density followed by cell damage lead to retardation in the vertical development of the palatal shelves.     

Autoradiographic and liquid scintillation assessment of beta-amino-propionitrile-induced inhibition of collagen maturation using 3H-proline and 3H-lysine

BAPN (0.1 mg/day) was injected into chick embryos for 4 days starting on the 7th day of incubation. On the 11th day, the embryos were administered either 3H-proline or 3H-lysine. 36 h later, the incorporation of each isotope by the periosteal osteogenic cells as well as into bone matrix was investigated by autoradiography. The incorporation of the two isotopes into whole bones was assessed by liquid scintillation counting. 3H-proline incorporation into the cellular or matrical compartments was unaffected by treatment. As compared to the controls, 3H-lysine label in BAPN-treated embryonic bones was significantly higher in the cellular compartment but was reduced over the bone matrix. The data provide the first direct morphological evidence that BAPN probably induces certain changes in the maturation of collagen involving lysyl residues which result in an inhibition of cross-linkage formation in collagen.     

Investigations of alkaline phosphatase Ca+2-ATPase and Na+, K+-ATPase during beta-APN-induced initial bone mineralization inhibition

Tibias of 6-day-old white Leghorn chick embryos treated with beta-aminopropionitrile (beta-APN; 0.1 mg/egg/day) for 4 days and injected with 3H-proline or 3H-tetracycline on the 11th day were analyzed for incorporation of 3H-proline and 3H-tetracycline. The incorporation of 3H-proline was comparable in the controls and beta-APN-treated embryos. However, the incorporation of 3H-tetracycline was significantly lower in beta-APN-treated embryos. The bone ash contents were also lower in the latter group. Alkaline phosphatase and Ca+2-ATPase were found to be significantly lower in beta-APN-treated embryonic bones. There was, however, no difference in the activity of Na+, K+-ATPase. The histochemical examination showed the alkaline phosphatase to be present on osteoblasts and matrix vesicle plasma membranes at the periosteal surface. The chick embryonic liver tissue showed no significant differences in the activities of any of the above enzymes. The results suggest that beta-APN-induced inhibition of the bone mineralization may be due to the bone-specific inhibition of alkaline phosphatase and Ca+2-ATPase.     

Transforming growth factor beta inhibits DNA synthesis in hepatocytes isolated from normal and regenerating rat liver

The inhibitory action of transforming growth factor beta (TGF beta) on DNA synthesis in hepatocytes isolated from the liver of normal rats or from the liver remnant of rats 18 h following partial hepatectomy was compared. Continuous exposure to TGF beta inhibited DNA synthesis of cultured hepatocytes to a similar degree in both groups when labelled with 3H thymidine from 24-48 h or 48-72 h. At 20 pM TGF beta, 3H-thymidine incorporation was reduced by 64-78% in hepatocytes from normal liver and by 60-73% in cells from 18 h regenerating liver. The nuclear labelling index was reduced by 70-80% in all cells. Exposure to TGF beta at concentrations up to 500 pM from 0-24 h had no effect on 3H-thymidine incorporation, but exposure at 20 pM for 24 h periods thereafter was uniformally effective. These results indicate that there is no change in sensitivity of hepatocytes from 18 h regenerating liver to TGF beta, compared with normal cells, and that TGF beta may act at some point in the G1 phase of the cell cycle to inhibit hepatocyte growth.     

Formation of the skeletal system of white rat and golden hamster embryos during experimental hypovitaminosis B1

In pregnant females B1-hypovitaminosis was induced by injecting various doses of oxythiamine--a specific antimetabolite for B1 vitamin. The rat and hamster embryos were respectively treated on the 20th and 15th days of development after the technique suggested by Dauson-Dyban with staining the osseous anlages of the skeletons with alizarine red. The results of the investigations performed in 193 skeletons of the rat embryos and in 196 skeletons of the golden hamster embryos revealed a progressive decrease, as the dose of oxythiamine increased, in length of ossification anlages of the extremity bones. However, susceptibility to lesions in various bones of the extremity and skull skeletons was not similar under conditions of progressive oxythiamine-induced B1-hypovitaminosis and depended on time of their anlage formations.     

Immediate and delayed effects of vincristine administered during early postimplantation stages of murine embryogenesis

Vincristine was given to pregnant mice on day 7 1/2 of pregnancy and the teratogenic effects of this treatment were assessed 2 and 3 days thereafter. Most of the embryos in litters removed on day 9 1/2 of pregnancy (2 days after treatment) were morphologically normal, whereas on day 10 1/2 most embryos were either developmentally retarded by the treatment or malformed. The morphologically "normal" embryos removed on day 9 1/2 of pregnancy were cultured in vitro for 24 h. During this procedure more than 50% of them showed growth retardation or abnormal development. These data indicate that exposure of early postimplantation embryos to vincristine has an immediate teratogenic and embryocidal action, and also a delayed effect which becomes apparent only several days after exposure and following an ostensibly "normal" period of embryonic development.     

An adenosine receptor agonist-induced modulation of TSH-dependent cell growth in FRTL-5 thyroid cells mediated by inhibitory G protein, Gi.

Adenosine has been shown to modulate the TSH-induced DNA synthesis in FRTL-5 thyroid cells. The mechanism of this adenosine action has been somewhat controversial because both A1 adenosine receptor-mediated and non-receptor-mediated mechanisms have been proposed. We have now reexamined our preliminary finding of the inhibitory action of a non-metabolizable adenosine derivative, N6-(L-2-phenylisopropyl)adenosine (PIA), on the TSH-induced DNA synthesis to clarify the adenosine-dependent mechanism of cell growth modulation. PIA dose-dependently inhibited the TSH-induced DNA synthesis expressed by [3H]thymidine incorporation into DNA. This adenosine derivative also prevented the TSH-induced entry of the cell cycle to the S phase at 24 h of culture and the increase in cell number at 48 h. These PIA actions on different aspects of TSH-dependent cell growth were abolished by the treatment of the cells with pertussis toxin, suggesting the involvement of Gi in the PIA action mechanism. Dibutyryl cAMP-induced DNA synthesis was not influenced by PIA. In concert with our previous finding that PIA in a similar concentration range inhibited TSH-induced cAMP production through the adenosine A1 receptor, the present results strongly support the idea that the major pathway of adenosine signaling for the inhibition of the TSH-induced cell proliferation is through the A1 adenosine receptor-Gi system.     

Comparative studies on acetazolamide teratogenesis in pregnant rats, rabbits, and rhesus monkeys

Acetazolamide produces a characteristic forelimb reduction deformity when administered to pregnant rodents. Past studies indicated that non-rodent species (rabbit and monkey) are resistant to this effect. The present studies confirmed this fact and demonstrated that transport of acetazolamide into the rabbit embryo was similar to that in sensitive rat embryos. In monkeys, however, the concentrations of acetazolamide within maternal plasma and embryo were much lower than in rats. Carbonic anhydrase activity was also measured since inhibition of this enzyme is the primary pharmacologic effect of acetazolamide. Again the rabbit embryo had carbonic anhydrase specific activity levels similar to that of the rat. Monkey embryos, on the other hand, contained negligible levels of enzyme activity during the presumed sensitive period of development. Thus the resistance of monkey embryos to acetazolamide teratogenesis may be due to low carbonic anhydrase activity and/or the small amount of drug reaching the embryo. No basis for the resistance of rabbit embryos to acetazolamide teratogenesis was uncovered.     

N^7＋重离子注入和贯穿后小麦种胚的期外DNA合成效应

用＾３ＨＴｄＲ掺入法研究了经Ｎ＾７＋重离子注入贯穿处理的８２５７９小麦和８８１２小麦种胚的ＤＮＡ合成动态。结果发现,未经Ｎ＾７＋重离子任何处理的两个小麦品种的对照种胚,在萌发早期（２０ｈ内）仅存在一个ＤＮＡ合成峰（于萌发的第１４ｈ）,而经过Ｎ＾７＋重离子注入和贯穿处理的小麦种胚则存在两个ＤＮＡ合成峰（分别于萌发的８－１０ｈ和１４－１６ｈ）,该种子经ＤＮＡ修复合成的抑制剂咖啡因处理后,第一个ＤＮＡ合     

Effects of secondary bile acids on the in vitro development of early somite rat embryos

Effects of secondary bile acids--lithocholic (LCA) and deoxycholic (DCA)--on the in vitro development of early somite (10.5 days old) rat embryos were studied. It was shown that an addition to the culture medium of 0.1 mM LCA (final concentration) resulted in 9% growth-retarded and 12% malformed embryos when the duration of exposure was 24 h. When treatment with LCA was prolonged to 48 h, the rate of growth retardation increased to 18% and that of malformations to 40% versus 0.5% for both parameters observed in controls. This could be interpreted as a reversible or time-dependent effect of LCA on the in vitro development of the mammalian embryo. Culture of embryos in medium with 0.5 mM DCA resulted in 22% of growth retardation and 50% of malformations. DCA in 0.1 mM final concentration had only slight and statistically nonsignificant effects. Retardation of growth development could be demonstrated by a decrease in crown-rump length and the number of somites. Among malformed embryos, abnormalities in the development of the neural tube and exencephaly were the most common types of malformations. Abnormalities as well as growth retardation were accompanied by significant pathological changes in structure and perhaps in function of the endodermal visceral yolk sac cells. It could be suggested that secondary bile acids when present in pathophysiological concentrations can affect the embryonic development by direct inhibitory effects and that these effects may be time and dose dependent.     

Several Cell Responses to Insulin of Cultured Cells Derived from Micromeres, Isolated from Sea Urchin Embryos at the 16 Cell Stage

In micromere-derived cells of sea urchin embryos, treatment with insulin started for up to 24 h during culture at 20°C resulted in augmentation of ³²P incorporation into protein (protein phosphorylation) followed by activation of ³²P incorporation into RNA (RNA synthesis) and then induced pseudopodial cable growth, accompanied by considerable decreases in the rates of protein phosphorylation and RNA synthesis. This augmentation of RNA synthesis and cable growth induced by insulin were blocked by H-7, which inhibited protein phosphorylation, and were also inhibited by actinomycin D without any inhibition of protein phosphorylation. Similar results were obtained on treatment with horse serum, found to contain insulin-like compounds. In cells treated with horse serum treated cells, high rates of protein phosphorylation and RNA synthesis were maintained even after the initiation of cable growth and about 5 h later, spicule rods were produced. Insulin treatment did not induce spicule rod formation. In cells treated with horse serum, actinomycin D treatment started at the time of initiation of cable growth, cables were formed but formation of spicule rods was blocked. These results suggest that horse serum contains some other substance besides insulin-like ones, which induces expression of genes that are indispensable for spicule rod formation.     

Prevention of spinal neural tube defects in the mouse embryo by growth retardation during neurulation

Homozygous mutant curly tail mouse embryos developing spinal neural tube defects (NTD) exhibit a cell-type-specific abnormality of cell proliferation that affects the gut endoderm and notochord but not the neuroepithelium. We suggested that spinal NTD in these embryos may result from the imbalance of cell proliferation rates between affected and unaffected cell types. In order to test this hypothesis, curly tail embryos were subjected to influences that retard growth in vivo and in vitro. The expectation was that growth of unaffected rapidly growing cell types would be reduced to a greater extent than affected slowly growing cell types, thus counteracting the genetically determined imbalance of cell proliferation rates and leading to normalization of spinal neurulation. Food deprivation of pregnant females for 48 h prior to the stage of posterior neuropore closure reduced the overall incidence of spinal NTD and almost completely prevented open spina bifida, the most severe form of spinal NTD in curly tail mice. Analysis of embryos earlier in gestation showed that growth retardation acts by reducing the incidence of delayed neuropore closure. Culture of embryos at 40.5 degrees C for 15-23 h from day 10 of gestation, like food deprivation in vivo, also produced growth retardation and led to normalization of posterior neuropore closure. Labelling of embryos in vitro with [3H]thymidine for 1 h at the end of the culture period showed that the labelling index is reduced to a greater extent in the neuroepithelium than in other cell types in growth-retarded embryos compared with controls cultured at 38 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)     

Studies on the growth of the fetal guinea pig. Effects of reduction in uterine blood flow on the plasma sulphation-promoting activity and on the concentration of insulin-like growth factors-I and -II

The effects of prenatal growth restriction caused by uterine artery ligation at midgestation has been studied in pregnant guinea pigs. Ligation of a uterine artery at day 30 of pregnancy commonly caused a reduction in fetal growth of greater than 45% by days 40-65 of gestation. This was associated with substantial delays in the development of a number of fetal tissues and in particular that of the skeleton which remained cartilagenous for longer than normal. Hence normally by day 50 of pregnancy clear evidence of epiphyseal ossification in the long bones of the fore- and hindlimbs was present, but in growth retarded fetuses of less than 50% of normal size such evidence was sparce. Delayed skeletal development and the slowing of fetal growth rate correlated well with marked depression of plasma sulphation-promoting activity. Indeed plasma from fetuses that were less than 40% of normal size inhibited sulphate incorporation into pig costal cartilage. This indicated the presence of inhibitory factors in the plasma of such fetuses, an interpretation that was re-inforced by the observation that plasma IGF-II concentrations were 2-4 times above normal. In contrast plasma IGF-I concentration was depressed upto 50% by growth retardation in line with the fall in fetal plasma insulin concentration. The changes in plasma sulphation-promoting activity and of IGF-I are consistent with slowing of DNA, RNA and protein synthesis and of gene expression in tissues of the growth-retarded fetus. The elevated fetal plasma IGF-II concentration provided further evidence that in the fetal guinea pig this hormone has a potentially glyconeogenic action and maintains essential glycogen stores.     

Aurintricarboxylic acid (ATA) and DNA synthesis. II. Effect of ATA on structure and function of the crypts of the small intestine.

ATA affects only slightly DNA synthesis of continuously replicating cells. A single injection of the drug reduces the incorporation of (3H)-thymidine into DNA of crypt cells to only 62% of the control. The effect on DNA synthesis is preceded by a slight inhibition of protein synthesis, and by a partial decrease in the number of dividing cells. On the contrary, the incorporation of (3H)-uridine into RNA was enhanced. Electron microscopic studies revealed no cytologic abnormalities in ATA-treated animals. In view of the fact that ATA at the same concentration inhibits DNA synthesis of growth stimulated cells to 100% (Novi, 1976), it was suggested that the drug may become an useful tool in inducing a preferential inhibition of growth stimulation.     

Differential effects of growth factors on [3H]thymidine incorporation and [125I]iodine uptake in FRTL-5 rat thyroid cells

We studied the effect of several growth factors on DNA synthesis and function of FRTL-5 rat thyroid cells by simultaneous measurement of [3H]thymidine incorporation and [125I]iodide uptake. Endothelial cell growth factor, fibroblast growth factor, platelet-derived growth factor, and insulin-like growth factor I stimulated thymidine incorporation in a dose-dependent manner without the parallel increase of [125I]iodide uptake. These growth factors had an additive effect with thyroid-stimulating hormone (TSH) on thymidine incorporation, but they inhibited TSH-stimulated iodide uptake. Bombesin stimulated thymidine incorporation and inhibited TSH-stimulated iodide uptake; epidermal growth factor and gastrin-releasing peptide 10 had neither effect. None of the growth factors studied affected iodide uptake in the absence of TSH. Of the growth factors tested, endothelial cell growth factor, fibroblast growth factor, insulin-like growth factor bombesin, and platelet-derived growth factor all share similar differential effects on FRTL-5 cells: stimulation of DNA synthesis, potentiation of the effects of TSH on DNA synthesis, and attenuation of the effects of TSH on cell function. The data suggest that these growth factors may play important roles in regulation of thyroid function.     

Growth inhibition of human embryonic and fetal rat bones in organ culture by rubella virus.

Paired organ cultures of metacarpal, metatarsal, and long bones of previable human embryos of 7 to 12 weeks' gestation and tibias of 17-day rat fetuses with inoculated with live or ultraviolet-inactivated rubella virus or control fluids and the growth of the bones was measured by increase in wet weight. In several cultures the ability of the human bones to incorporate 35S, a measure of rate of mucopolysaccharide synthesis, was tested. Growth of human and rat bones was retarded in cultures inoculated with live virus but not in cultures inoculated with inactivated virus or control fluids. Mean 35S uptake was increased by approximately 25% in virus-inoculated cultures of bones of 9- to 12-week human embryos. No histological abnormalities were seen. These findings suggest that (1) defective bone growth in congenital rubella is a direct effect of viral infection of bone, (2) a disorder of mucopolysaccharide syntheses may contribute to the osseous lesions that occur in this disease, and (3) organ cultures of human embryonic and fetal rat bones may serve as convenient models for studying the pathogenesis of this virus-induced congenital osteopathy.