The adaptation of a two-compartment cell renewal system to external demands

1978 ◽  
Vol 194 (1) ◽  
pp. 163-170 ◽  
Author(s):  
Yael Michaeli ◽  
Gershom Zajicek ◽  
Joseph Regev
Keyword(s):  
Cell Renewal ◽  
Renewal System ◽  
Compartment Cell

Cell Renewal in the Gill of the Freshwater Mussel, Margaritifera Margaritifera: An Autoradiographic Study using High Specific Activity Tritiated Thymidine

1974 ◽  
Vol 14 (3) ◽  
pp. 561-569
Author(s):  
S. P. TOMASOVIC_ ◽  
M. C. MIX
Keyword(s):  
Specific Activity ◽  
Tritiated Thymidine ◽  
High Specific Activity ◽  
Freshwater Mussel ◽  
Autoradiographic Study ◽  
Cell Renewal ◽  
Margaritifera Margaritifera ◽  
Gill Epithelium ◽  
Stem Type ◽  
Renewal System

High specific activity tritiated thymidine (50.3 Ci/mM and 56 Ci/mM) and autoradiographic techniques were used to study cell renewal in the gill epithelium of the freshwater mussel, Margaritifera margaritifera. The cell renewal system in the gill epithelium of M. inargaritifera appears to consist of a stem-type population in the gill furrow and gill furrow edges which supplies, through division, cells for a maturing, dividing transient transitional population along the proximal gill ridge sides which, in turn, supplies cells to a simple transient, differentiated, functional population on the distal gill ridge sides and tip. Loss of cells from the cell renewal system appears to be through cell death and/or extrusion from the gill ridge tip. No emigration or immigration of labelled nuclei out of, or into, the gill epithelium was observed. The minimum transit time from the dividing transient population to the functional population in the gill ridge tip may be no more than 24 h. We were unable to detect any radiobiological effects or the presence of cytoplasmic labelling due to the use of high specific activities. However, such possibilities cannot be eliminated from consideration in further studies.

Cell renewal in the gills of the fish Barbus conchonius

1980 ◽  
Vol 58 (4) ◽  
pp. 650-653 ◽  
Author(s):  
Marlene MacKinnon ◽  
Hildegard E. Enesco
Keyword(s):  
Cell Migration ◽  
Cell Division ◽  
Epithelial Cells ◽  
Gill Filament ◽  
Gill Arch ◽  
Tropical Fish ◽  
Time Interval ◽  
Cell Renewal ◽  
A Cell ◽  
Renewal System

This radioautographic study established that the epithelial cells of the teleost gill have the cell division and cell migration patterns characteristic of a cell renewal system. [3H]Thymidine was injected into the small tropical fish Barbus conchonius, where it became incorporated into the newly synthesized DNA of dividing cells. Three fish were sacrificed at each of the following postinjection time intervals: 1, 12, 24, and 36 h. At 1 h, labeled nuclei were found only at the base of the gill filament, near the gill arch. At each successive time interval, labeled nuclei were found further out along the length of the gill filament. At later stages, labeled nuclei were also seen at the tips of the lamellae which project perpendicularly from the filaments. The number of labeled nuclei at the point of origin steadily declined with time. These data demonstrate that gill epithelial cells originate at the base of the gill arch and migrate both outward along the filament and upward along the lamellae. This pattern of cell division and cell migration demonstrates that the gill epithelium is a cell renewal system.

Cell renewal in human epidermis

1965 ◽  
Vol 92 (4) ◽  
pp. 462-468 ◽  
Author(s):  
W. L. Epstein
Keyword(s):  
Human Epidermis ◽  
Cell Renewal

Progestation

1967 ◽  
Vol 56 (3_Suppla) ◽  
pp. S7-S45 ◽  
Keyword(s):  
Tritiated Thymidine ◽  
Succinic Dehydrogenase ◽  
Glandular Epithelium ◽  
Synthetic Activity ◽  
Cell Renewal ◽  
Pulse Labelling ◽  
Uterine Receptivity ◽  
Alkaline Phosphatases ◽  
Monocytic Cells ◽  
Acid And Alkaline Phosphatases

ABSTRACT Autoradiographic, enzymic and histologic studies on uteri of pregnant rats were carried out to follow the endometrial modifications which take place during progestation (days L0 – L4) and culminate in the state of uterine receptivity essential for ovum-implantation. Pulse labelling with tritiated thymidine (radioactive DNA precursor) on L0, L1 and L2 revealed a sequence of cell renewal in luminal and glandular epithelium and endometrial stroma. On L3 and L4 stromal cells showed extensive incorporation of tritiated thymidine. This synthetic activity was associated with endometrial preparation for decidualization and was evoked at least in part, by the surge of oestrogen on L3. All layers of the uterine wall were heavily infiltrated on L0 and resembled the site of an acute inflammatory reaction. Subsequently, polymorphonuclear infiltration diminished and monocytic cells predominated. On L3 a spatial arrangement was observed: eosinophiles were concentrated in the basal endometrium and monocytic cells in the subepithelial stroma. A comparison was made between such a shift in migratory cells in the uterus and similar phenomena which occur in inflammatory and immune reactions. Activities of acid and alkaline phosphatases, of ATP-ase and succinic dehydrogenase were low on L0 and L1 during the periods of infiltration, degeneration and regeneration of luminal and glandular epithelium. Enzymic activities increased on the following days, (L3 and L4). Vascular dilation and engorgement and endometrial oedema were observed near the blastocysts on L4. Most blastocysts incorporated tritiated thymidine after 14.00 h on L4, but some showed uptake before loss of the zona which occurs usually between 14.00 and 16.00 h; therefore, it was assumed that the permeability of the zona increases prior to being shed. Activities of succinic dehydrogenase and acid and alkaline phosphatases were demonstrable in blastocysts on L4 while they were still »free« in the uterine lumen.

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