Abstract
The rates of uptake of 125I-labelled poly(vinylpyrrolidone), [14C]sucrose and colloidal [198Au]gold by 17.5-day rat yolk sac cultured in vitro were studied. Over a 6.5h period each substrate was accumulated at a constant and reproducible rate of approx. 2microliter/h per mg of protein. After accumulation in vitro, the three substances were released from the tissue into substrate-free medium at low rates. Sucrose present in the medium at concentrations up to 10 mg/ml was without effect on the accumulation of either [14C]sucrose or 125I-labelled poly(vinylpyrrolidone), but at higher concentrations inhibited the uptake of both substrates. Some batches of colloidal [198Au]gold had a significantly higher Endocytic Index (up to 5 microliter/h per mg of protein). The Endocytic Index of such a batch decreased with increasing substrate concentration, but colloidal gold did not decrease the Endocytic Index of 125I-labelled poly(vinylpyrrolidone). It is concluded that the three substrates enter the yolk sac by pinocytosis in the liquid phase. Those batches of colloidal [198Au]gold with higher Endocytic Indices are considered to enter also by adsorption on membrane binding-sites.
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- Caro R. A., Ciscato V. A., Radicella R. Kinetics of the phagocytosis of radiogold colloids by the reticuloendothelial system in the rat. Int J Appl Radiat Isot. 1970 Jul;21(7):405–414. doi: 10.1016/0020-708x(70)90134-1. [DOI] [PubMed] [Google Scholar]
- Dingle J. T., Fell H. B., Glauert A. M. Endocytosis of sugars in embryonic skeletal tissues in organ culture. IV. Lysosomal and other biochemical effects. General discussion. J Cell Sci. 1969 Jan;4(1):139–153. doi: 10.1242/jcs.4.1.139. [DOI] [PubMed] [Google Scholar]
- LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
- Moore A. T., Williams K. E., Lloyd J. B. The effect of chemical treatments of albumin and orosomucoid on rate of clearance from the rat bloodstream and rate of pinocytic capture of rat yolk sac cultured in vitro. Biochem J. 1977 Jun 15;164(3):607–616. doi: 10.1042/bj1640607. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Normann S. J., Benditt E. P. Function of the reticuloendothelial system. I. A study on the phenomenon of carbon clearance inhibition. J Exp Med. 1965 Oct 1;122(4):693–707. doi: 10.1084/jem.122.4.693. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Roberts A. V., Nicholls S. E., Griffiths P. A., Williams K. E., Lloyd J. B. A quantitative study of pinocytosis and lysosome function in experimentally induced lysosomal storage. Biochem J. 1976 Dec 15;160(3):621–629. doi: 10.1042/bj1600621. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wagner R., Rosenberg M., Estensen R. Endocytosis in Chang liver cells. Quantitation by sucrose- 3 H uptake and inhibition by cytochalasin B. J Cell Biol. 1971 Sep;50(3):804–817. doi: 10.1083/jcb.50.3.804. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Williams K. E., Kidston E. M., Beck F., Lloyd J. B. Quantitative studies of pinocytosis. I. Kinetics of uptake of (125I)polyvinylpyrrolidone by rat yolk sac cultured in vitro. J Cell Biol. 1975 Jan;64(1):113–122. doi: 10.1083/jcb.64.1.113. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Williams K. E., Kidston E. M., Beck F., Lloyd J. B. Quantitative studies of pinocytosis. II. Kinetics of protein uptake and digestion by rat yolk sac cultured in vitro. J Cell Biol. 1975 Jan;64(1):123–134. doi: 10.1083/jcb.64.1.123. [DOI] [PMC free article] [PubMed] [Google Scholar]