Abstract
The epithelium of lenses cultured in KEI-4, a completely defined medium formulated with specific reference to the biochemistry and physiology of the rabbit lens, exhibits a pattern of cell division similar to that noted for the organ in situ. Initial fluctuations in mitotic activity occurred in the area of the germinative zone during the first 24 hr of culture. Mitosis decreased at 1 hr, was extremely low at 3 hr and returned to values comparable for lens in vivo by 22 hr. The precipitous drop in mitosis noted at 3 hr is in part attributable to the isolation of the lens from adjoining tissue. The addition of insulin to KEI-4 triggers a parasynchronous burst of DNA synthesis throughout the central lens epithelium. The activation requires the intact hormone; neither proinsulin nor the A and/or B chains of insulin, nor glucagon nor zinc chloride can initiate mitosis. The gamma-globulin-rich fraction of rabbit serum can also stimulate mitosis. The addition of dibutyryl adenosine 3':5' cyclic monophosphate (DBeAMP) plus theophylline to KEI-4-insulin inhibits mitosis and prevents the cells from entering the synthetic phase of the cell cycle. Theophylline alone or DBeAMP alone brings about a 90 percent reduction in the insulin-induced mitotic responses.
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Citation Formats
Reddan, J R, Unakar, N J, Harding, C V, Bagchi, M, and Saldana, G.
Induction of mitosis in the cultured rabbit lens initiated by the addition of insulin to medium KEI-4.
United Kingdom: N. p.,
1975.
Web.
doi:10.1016/0014-4835(75)90107-4.
Reddan, J R, Unakar, N J, Harding, C V, Bagchi, M, & Saldana, G.
Induction of mitosis in the cultured rabbit lens initiated by the addition of insulin to medium KEI-4.
United Kingdom.
https://doi.org/10.1016/0014-4835(75)90107-4
Reddan, J R, Unakar, N J, Harding, C V, Bagchi, M, and Saldana, G.
1975.
"Induction of mitosis in the cultured rabbit lens initiated by the addition of insulin to medium KEI-4."
United Kingdom.
https://doi.org/10.1016/0014-4835(75)90107-4.
@misc{etde_7196856,
title = {Induction of mitosis in the cultured rabbit lens initiated by the addition of insulin to medium KEI-4}
author = {Reddan, J R, Unakar, N J, Harding, C V, Bagchi, M, and Saldana, G}
abstractNote = {The epithelium of lenses cultured in KEI-4, a completely defined medium formulated with specific reference to the biochemistry and physiology of the rabbit lens, exhibits a pattern of cell division similar to that noted for the organ in situ. Initial fluctuations in mitotic activity occurred in the area of the germinative zone during the first 24 hr of culture. Mitosis decreased at 1 hr, was extremely low at 3 hr and returned to values comparable for lens in vivo by 22 hr. The precipitous drop in mitosis noted at 3 hr is in part attributable to the isolation of the lens from adjoining tissue. The addition of insulin to KEI-4 triggers a parasynchronous burst of DNA synthesis throughout the central lens epithelium. The activation requires the intact hormone; neither proinsulin nor the A and/or B chains of insulin, nor glucagon nor zinc chloride can initiate mitosis. The gamma-globulin-rich fraction of rabbit serum can also stimulate mitosis. The addition of dibutyryl adenosine 3':5' cyclic monophosphate (DBeAMP) plus theophylline to KEI-4-insulin inhibits mitosis and prevents the cells from entering the synthetic phase of the cell cycle. Theophylline alone or DBeAMP alone brings about a 90 percent reduction in the insulin-induced mitotic responses. Lenses exposed to insulin show a marked increase in RNA synthesis and also exhibit an increased binding of tritiated actinomycin D at 1 and 3 hr of culture relative to KEI-4 controls. The hormone apparently activates the genome including those genes governing cell division. The system is amenable for long-term culture of the mammalian lens and since the constituents of the medium are known it should be possible to determine the factor(s) in the medium which, in conjunction with insulin, are needed for the induction of cell division.}
doi = {10.1016/0014-4835(75)90107-4}
journal = []
volume = {20}
journal type = {AC}
place = {United Kingdom}
year = {1975}
month = {Jan}
}
title = {Induction of mitosis in the cultured rabbit lens initiated by the addition of insulin to medium KEI-4}
author = {Reddan, J R, Unakar, N J, Harding, C V, Bagchi, M, and Saldana, G}
abstractNote = {The epithelium of lenses cultured in KEI-4, a completely defined medium formulated with specific reference to the biochemistry and physiology of the rabbit lens, exhibits a pattern of cell division similar to that noted for the organ in situ. Initial fluctuations in mitotic activity occurred in the area of the germinative zone during the first 24 hr of culture. Mitosis decreased at 1 hr, was extremely low at 3 hr and returned to values comparable for lens in vivo by 22 hr. The precipitous drop in mitosis noted at 3 hr is in part attributable to the isolation of the lens from adjoining tissue. The addition of insulin to KEI-4 triggers a parasynchronous burst of DNA synthesis throughout the central lens epithelium. The activation requires the intact hormone; neither proinsulin nor the A and/or B chains of insulin, nor glucagon nor zinc chloride can initiate mitosis. The gamma-globulin-rich fraction of rabbit serum can also stimulate mitosis. The addition of dibutyryl adenosine 3':5' cyclic monophosphate (DBeAMP) plus theophylline to KEI-4-insulin inhibits mitosis and prevents the cells from entering the synthetic phase of the cell cycle. Theophylline alone or DBeAMP alone brings about a 90 percent reduction in the insulin-induced mitotic responses. Lenses exposed to insulin show a marked increase in RNA synthesis and also exhibit an increased binding of tritiated actinomycin D at 1 and 3 hr of culture relative to KEI-4 controls. The hormone apparently activates the genome including those genes governing cell division. The system is amenable for long-term culture of the mammalian lens and since the constituents of the medium are known it should be possible to determine the factor(s) in the medium which, in conjunction with insulin, are needed for the induction of cell division.}
doi = {10.1016/0014-4835(75)90107-4}
journal = []
volume = {20}
journal type = {AC}
place = {United Kingdom}
year = {1975}
month = {Jan}
}