Serotonin levels in plasma and platelets of cyclosporin a treated rats

Nephrotoxicity of cyclosporin A[CsA] is the major side effect of this potent immunosuppressive drug. In order to evaluate the involvement of serotonin in CsA nephrotoxicity, rats were treated with different doses [1,10,30 and 100 mg/kg/day] of CsA on four consecutive days. Elevated serum urea and creatinine levels was accompanied by structural evidence of varying degrees of cytoplasmic proximal tubular vacuolization. These biochemical and pathologic changes were accompanied by an elevation of serotonin level in plasma and the depletion of serotonin content of the platelets. It is suggested that the elevated plasma levels of serotonin in CsA treated rats may be the result of platelet activation and degranulation

Elevation of serotonin level in serum and platelets of rats with glycerol-induced acute renal failure

The effect of glycerol-induced acute renal failure [ARF] on serotonin [STN] was studied in rats. The levels of STN in plasma and platelets [PT] were measured by high performance liquid chromatography [HPLC]. The concentration of STN in platelets [4483 +/- 875 ng/10[9] PT] and plasma [83.50 +/- 9.75 ng/ml plasma] were higher than that of healthy controls [2746 +/- 766 ng/10[9] PT, p < 0.01; 13.67 +/- 3.00 ng/ml, P < 0.01, respectively]. The observed alteration is believed to be due to decreased renal blood flow and low glomerular filtration rate [GFR] caused by vasoconstriction in the presence of high levels of STN as well as renal insufficiency. In addition, tryptophan, [Try] which acts as the precursor of STN was significantly lower in the plasma of rats with ARF [6.97 +/- 2.03 micro g/ml] compared to control rats [12.87 +/- 2.54 micro g/ml, P<0.01]