AIM: To investigate the heterogeneity of basal intracellular free calcium concentration( i) in peritoneal macrophages(PM) and whether it is relative to the reactivity of PM at the single cell level. METHODS: i implicated stimulated were measured by fluorescent microscopic imaging system after loading with fluorescent probe fura-2/AM. Superoxide(O _2)produced by single PM was determined by modified NBT test. RESULTS: The values of basal i determined in 392 PMs of 7 mice showed normal distribution [(54?24) nmol/L, n=392] with wide range(less than 20 nmol/L to more than 100 nmol/L), among which about 50% were in the range of 40-60 nmol/L. When stimulated with PMA or fMLP, i was increased, the peak values were positively correlated with the basal i in one mouse(PMA stimulated cells: r=0.52, P

By using single spleen colony transplantation technique and sex chromosome typing as natural cytogenetic markers, we have been able to demonstrate that most spleen colony forming cells in the adult bone marrow or in foetal liver of inbred LACA or C57 mice possess the potential of re-establishment of myeloid and lymphoid lines of cells in lethally irradiated mice. However, most of the spleen colony forming cells in the peripheral [blood of normal mice possess weak or no potentiality to proliferate or re-establish hemopoiesis in lethally irradiated mice. Our results support the notion that the CFU-S population in mice is heterogeneous.From the nature of colony forming cells in the peripheral blood of normal mice, we are convinced that the assessment of CFU-S content relying upon the spleen colonies as the unique sign to indicate the self-renewal ability of a spleen colony forming cell is by no means valid inasmuch as some plu-ripotent . hemopoietic progenitors derived from pluripotent hemopoietic stem cells may have the same ability to form colonies in vivo.

The high-affinity glucocorticoid binding sites (HAGS) and the low-affinity glucocorticoid binding sites (LAGS) with steroid specificity were demostrated in cerebral cytosol of rats by using the radioligand binding assay. The Kd of HAGS and LAGS were (178?0.71)?l0-8mol/L and (2.12?1.06)?10-6mol/L respecitively as estimated by Scatchard and Pseudoscatchard analysis. Glucocorticoid receptors (GR) in the traumatized(left) hemisphere cytosol were decreased more significantly than those in both the control (right) hemisphere cytosol at 6h postinjury and normal brain tissue (P

The present study was undertaken by radioligand binding assay to compare the binding properties of U72099E to cytosol and synaptic plasma membrane (SPM)preparations of rat brain. The results showed that the binding of [3H]Glucocorticoids ([3H]GC) was not displaced by U72099E in cytosol but was displaced in SPM with a Ki of 32.2?1.7?mol/L-1,indicating the existence of binding sites for U72099E in plasma membrane (most probably being glucocorticoid membrane receptors, GCMR). The Ki of U72099E is close to the concentrations needed to mimic the actions of it to protect against brain injury, suggesting that GCMR may mediate the beneficial effect of U72099E.