フロリヂンの腎機能に及ぼす影響

抄録

In order to investigate mechanism of phlorizin action, there were observed effects of a single intravenous administration of this drug on renal clearances in man and rabbits. Simultaneous thiosulfate, endogenous creatinine, glucose and PAH clearances in man were measured by means of the simplified method, and exogenous creatinine clearance and glucose Tm in rabbits were measured by the continuous intravenous infusion of creatinine and glucose solution. Results are as follows : 1) The administration of phlorizin in man causes a marked reduction in endogenous creatinine, thiosulfate and PAH clearances, above all the more marked reduction in PAH clearance as against other clearances raises the filtration fraction. It gives a proof that phlorizin brings about renal circulatory disturbances, presumably accompanying secondary reduction in thiosulfate and endogenous creatinine clearances.2) The intravenous administration of phlorizin in adequate doses enables to raise the glucose/endogenous creatinine clearance ratio to 1.0; and the minimum intravenous dose of phlorizin required in the normal man to raise the glucose clearance to thiosulfate or endogenous creatinine clearance was found to be in the neighbourhood of 10mg. per kg. body weight, and this dose not show significant deviation between the normal and the renal diseases or hypertension. This fact is interpreted as indicating that phlorizin may paralyze completely the tubular reabsorption of glucose.3) It may be noted that exogenous creatinine clearance and glucose Tm decreased in phlorizinized rabbits, and that especially glucose Tm dropped from an average value of 28.52mg/min to about 0 after the administration of large dose of this drug (above 119mg. per kg. body weight). This demonstrates the complete inhibition of the tubular reabsorption of glucose.4) The thiosulfate/endogenous creatinine clearance ratio was not affected appreciably after phlorizination in the normal, renal diseases and hypertension.5) For the increase of urine flow and the decrease of RR (water reabsorption) after administration of this drug, it seems due to chiefly osmotic action offered by gluose in tubular urine and perhaps partly depressive action on the water rebsorptive function of phlorizin per se.6) It is reacognized that phlorizin dose not affect appreciably blood pressure in the normal, renal disease and hypertension.7) There were no objective or subjective unfavorable reactions after the intravenous administration of phlorizin in the normal man, but the increase of oedema and the decrease of urine flow were observed temporarily in a few of the nephrotic syndrome.In conclusion, it is confirmed that the intravenous administration of phlorizin depresses the tubule reabsorption of glucose and its large dose enables the complete inhibition. The renal circulatory disturbances caused by phlorizin bring about marked reduction in all renal clearances, and the accompanying diuresis is due to mostly osmotic action offered by glucose in tubular urine and partly taking part in depressive action on the water reabsorptive function of phlorizin per se.