Full text in pdf format

A quantitative study of human amniotic fluid fibronectin in the second trimester of pregnancy

Gifone A. Rocha; Sérgio D.J. Pena

Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Caixa Postal 2486, 30161 Belo Horizonte, MG, Brasil. Send correspondence to S.D.J.P.

ABSTRACT

We determined by electroimmunoassay the concentration of fibronectin in 60 samples of second trimester amniotic fluid obtained from normal pregnancies. We found a mean fibronectin concentration of 142 +/_; 7 jig/ml (mean +/_; SEM), corresponding to 3.1%; of the total amniotic fluid protein. The fibronectin levels rised significantly from the 14th to the 24th week of gestation and showed a significant negative correlation with the concentration of a-fetoprotein in the specimens. This correlation appeared to be spurious and due to an effect of gestational age upon both variables.
The level of amniotic fluid protein was within normal limits in two samples from pathological fetuses: one with Down syndrome (trisomy 21) and one with anencephaly.

Keywords: human; amniotic; fluid; fibronectin; pregnancy.

REFERENCES

Bradford, M.M. (1976). A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. AnaL Biochem. 72: 248-254.

Chen, A.B., Mosesson, M.W. and Solishi, G.I. (1976). Identification of the cold insoluble globulin of plasma in amniotic fluid. Am. J. Obstet. GynecoL 125: 958-961.

Crouch, E., Balian, G., Holbrook, K., Duksin, D. and Bornstein, P. (1978). Amniotic fluid fibro-nectin: characterization and synthesis by cells in culture. J. Cell Biol. 78: 701-715. Hynes, R.O. (1986). Fibronectins. Sci. Am. 254: 32-41.

Hynes, R.O. and Yamada, K.M. (1982). Fibronectins: multifunctional modular glycoproteins. J. Cell Biol. 95: 369-377.

Krusius, T., Fukuda, M., Dell, A. and Ruoslahti, E. (1985). Structure of the carbohydrate units of human amniotic fluid fibronectin. J. Biol Chem. 260: 4110-4116.

Kuusela, P., Seppala, M., Brock, D.J.H., Ruusuvaara, L. and Ruoslahti, E. (1978). Amniotic fluid fibronectin in normal pregnancy and in pregnancies with anencephalic fetus. Biomedicine 29: 296-299.

Laurel, C.-B. (1972). Electroimmuno assay. Scand. J. Clin. Lab. Invest. 29 (suppL 124): 21-37.

Matsuura, H. and Hakomori, S.-I. (1985). The oncofetal domain of fibronectin defined by monoclonal antibody FDC-6: its presence in fibronectins from fetal and tumor tissues and its absence in those from normal adult tissues and plasma. Proc Nat1 Acad. Sci. (USA). 82: 6517-6521.

Mosesson, M.W., Chen, A.B. and Huseby, R.M. (1975). The cold-insoluble globulin of human plasma: studies of its essential features. Biochim. Biophys. Acta 386: 509-524.

Pande, H., Corkill, J., Sailor, R. and Shively, J.E. (1981). Comparative structural studies of human plasma and amniotic fluid fibronectin. Biochem. Biophys. Rex Commun 101: 265-272.

Pena, S.D.J., Mills, G., Hughes, R.C. and Aplin, J. (1980). Polypeptide heterogeneity of hamster and calf fibronectins. Biochem J. 189: 337-347.

Rocha, G.A. and Pena, S.D.J. (1984). Absence of genetic polymorphism of human plasma fibronectin studied by immunoelectrophoresis. Hum. Hered 34: 334-336.

Ruoslahti, E., Engvall, E., Hayman, E.G. and Spiro, R.G. (1981). Comparative study on amniotic fluid and plasma fibronectins. Biochem J. 193: 295-299.

Tamkun, J.W., Schwarzbauer, J.E. and Hynes, R.O. (1984). A single rat fibronectin gene generates three different mRNAs by alternative splicing of a complex exon. Proc. Natl. Acad. Sci (USA) 81:5140-5144.

Wald, N.J. and Cukie, H.S. (1979). Amniotic-fluid alpha-fetaprotein measurements in antenatal diagnosis of anencephaly and open spina bifida in early pregnancy - Second report of the U.K. Collaborative Study on Alpha-fetoprotein in Relation to Neural-tu be defects. Lancet ii: 651662.