Tissue and subcellular distribution of zinc-65 in normal and zinc sulphate administered rats

Uptake of 65Zn by various organs of normal and ZnSO4 administered rats has been studied. Except duodenum and blood all the organs show low 65Zn incorporation in treated rats. The lower 65Zn incorporation in the tissues of ZnSO4 treated rats is due to the active turnover of zinc in these tissues. The maximum activity of 65Zn is exhibited by skin, followed in decreasing order by liver, intestine, spleen, rectum, kidney, prostate, urinary bladder, stomach, pancreas, adrenals, trachea, lungs, heart, thymus, seminal vesicles, testis, cauda epididymis, caput epididymis, brain, and muscle. Since ZnSO4 administration enhanced the levels of inert zinc in liver and intestine it is likely that accumulated inert zinc in the tissues may inhibit the further incorporation of 65Zn in these tissues. At subcellular level, the cytosol fraction (11000 g supernatant fraction) exhibits the higher 65Zn activity, followed in decreasing order by 300 g fraction (cell membranes and cell debris), 900 g fraction (nuclei), 6000 g fraction (heavy mitochondria) and 1000 g fraction (light mitochondria). The 65Zn activity/mgprotein in 11000 g fraction (light mitochondria) is more than the 900 g fraction (nuclei) and 6000 g fraction (heavy mitochondria). Subcellular distribution pattern of 65Zn in liver, intestine, kidney and testis is similar. ZnSO4 administration does not change the tissue and subcellular distribution pattern of 65Zn. (author). 18 refs., 3 tables