threshold substance

(redirected from threshold body)

thresh·old sub·stance

any material (for example, glucose) that is excreted in the urine only when its plasma concentration exceeds a certain value, termed its threshold.
Synonym(s): threshold body
Farlex Partner Medical Dictionary © Farlex 2012

thresh·old sub·stance

(thresh'ōld sub'stăns)
Any material (e.g., glucose) that is excreted in the urine only when its plasma concentration exceeds a certain value, termed its threshold.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

threshold substance

A substance present in the blood that, on being filtered through glomeruli of the kidney, is reabsorbed by the tubules up to a certain limit, that being the upper limit of the concentration of the substance in normal plasma. High-threshold substances (such as chlorides or glucose) are entirely or almost entirely reabsorbed. Low-threshold substances (such as phosphates or urea) are reabsorbed in limited quantities. No-threshold substances (such as creatinine sulfate) are excreted entirely.
Medical Dictionary, © 2009 Farlex and Partners
References in periodicals archive ?
Therefore, despite the identical nature of the relations (15) and (20), we can expect that this strategy (16) and (17) minimize the probability of error in the threshold body. However, simply proceed from the fact that the probability of an error is determined by the threshold body.
Below the threshold body size/stage of development, the only developmental response possible is to remain in the larval life history stage.
Wilbur and Collins proposed that individual larvae are on a fixed course of development, albeit played out at different rates, depending on the environment, until the threshold body mass is surpassed.
Determination of the threshold body mass.--Individual larvae in Experiment 2 were weighed on the day their food supply was eliminated.
These calculated threshold body lengths corresponded to measured threshold body lengths of 200 mm and 230 mm on Genovesa, and 310 mm and 350 mm on Santa Fe (1991/1992 and 1992/1993 in Fig.
The threshold body lengths above which iguanas on a given island lost mass are shown in Fig.
Evidence for an upper threshold body size for Santa Cruz marine iguanas comes also from a feeding experiment by Karl Angermeyer, a German settler who fed iguanas regularly for [greater than]20 years.