Temperature and salt effects on water and electrolyte metabolism of thyroid slices

¹ Department of Research Physiology, William H. Singer Memorial Research Laboratory, Allegheny General Hospital, Pittsburgh, Pennsylvania

Groups of bovine thyroid slices were incubated under oxygen with shaking for 1 hour at temperatures from 10° to 40°C in 5° increments, and at 38°C with media of 0.7, 0.8, 0.9 and 1.0% sodium chloride. The media of tissues at each temperature or salinity gradient contained Na²⁴, I¹³¹ or I¹³¹-4-iodoantipyrine. Pre- and postincubation wet weights and final dry weight, gain in water and gain of radioactivity during incubation of tissue slices at each gradient was measured. With rising temperature gradients I¹³¹ uptake by slices increased, and with increased salinity I¹³¹ uptake decreased. In both cases, with increased gradients, the degree of swelling was decreased, Na²⁴ space remained unchanged and the I¹³¹-antipyrine space increased compared to the media. It was concluded the response of thyroid slices to the external environment could be best explained in terms of the anatomical structure of the follicle. The metabolic effects of temperature and osmotic changes directly influenced the metabolism of water and electrolytes of the thyroid slice and were reflected in changes of I¹³¹ metabolism.