Sudden volume changes of the lumen of inverted thyroid follicles in suspension cultures. Use in estimation of rates of water flux through thyroid epithelium.
Inverted thyroid follicles in suspension culture were observed using dark-field illumination and time-lapse video enhancement techniques. The lumens of many follicles undergo episodes of rapid shrinkage followed by relatively slow dilation. The extent of shrinkage ranged from 10 to 40% of the initial diameter. The decrease in lumen diameter is accompanied by loss of luminal fluid. The rate of efflux of fluid amounted to from 1 to 90 microns3/micron2 of luminal surface/min. This was followed after several minutes by a slow and generally linear increase in lumen diameter with time that could be accounted for by an influx of fluid of the order of 0.5 micron3/micron2/min. It is possible that this phenomenon is due to a continued influx of fluid into the lumen until a junction opens between cells allowing a sudden loss of luminal fluid. The junction reseals and fluid begins to accumulate in the lumen. The phenomenon may be a three-dimensional analogue of the behavior of domes.
D000818:Animals; D046508:Culture Techniques; D005110:Extracellular Space / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D051381:Rats; D013961:Thyroid Gland / Q000166:cytology* / Q000378:metabolism