The influence of posture on renal activity.

Abstract

The influence of posture on the renal output of water, bicarbonate, chloride, inorganic phosphate, inorganic sulphate, urea, ammonia, creatinine and titratable acid, on urine pH, on blood pressure, pulse rate, circulation rate and rate of metabolism has been studied. The procedure was as follows: The subject took no food or water after ten p. m. of the evening preceding an experiment. At eight a. m, he emptied the bladder, discarding the urine, drank 200 cc. of tap water and stood or lay for two hours, at the end of which he voided, drank another 200 cc. of water and lay or stood for another two hour period. At the end of each two hour period he emptied the bladder and drank another 200 cc. of water. The order of lying and standing periods was varied in the various experiments. Each experiment was continued for four consecutive two hour periods. Nine experiments were performed on three subjects, four on subject H, aged 18 years, three on subject D, aged 30, and two on subject S, aged 50. The circulation rate for a ten minute period was determined by Henderson's and Haggard's method 1 in at least one lying and one standing period. During the period of circulation rate determination, ten arterial blood pressure readings were made, using the auscultatory and graphic (Erlanger instrument) methods simultaneously. Each blood pressure and pulse rate figure given in the table is thus the average of ten readings. No food was taken during the experiment and no water except the 200 cc. at the beginning of each period.

The circulation rate, blood pressure and metabolism figures are not presented because of lack of space. In every case the general circulation rate was greater in the recumbent posture and in all the experiments except those on subject S the mean arterial blood pressure was lower in the recumbent.