
the role of aldosterone and vasopressin in the postural
changes in renal excretion in normal subjects
and patients with idiopathic edema
the effects of the upright posture
(leisurely walking for 2 hours) on half-
hourly urine volume, and excretion of
sodium and creatinine were studied in
13 normal subjects and 13 patients with
idiopathic edema, while they drank 150
or 300 ml. of 0.14 per cent sodium
chloride solution every half hour.  when
the 2 hours of walking were compared
with a preceding recumbent period of
4 hours, both groups were found to show
a significant antidiuresis upright.  the
administration of ethanol during the last
half hour of recumbency abolished the
fall in urine flow and in free water clear-
ance during the first hour of walking in
the normal subjects and significantly re-
duced this fall in the patients with
edema.  sodium excretion in the normal
subjects was slightly but not significantly
lower when upright than when recum-
bent, but in the edematous patients was
significantly lower when upright and fell
progressively over the 2 hour period.  ad-
ministration of spironolactone or d-
amphetamine increased sodium excretion
during recumbency in both groups but
increased sodium excretion upright only
in the edematous patients to equal that
of the normal subjects.  creatinine excre-
tion was not changed in either group by
posture or drug therapy.  similar studies
were performed on 5 patients with un-
treated diabetes insipidus and on 6 pa-
tients with adrenal insufficiency treated
with hydrocortisone alone.  lack of al-
dosterone (in adrenal insufficiency) did
not increase the amount of sodium ex-
creted above that of normal subjects in
recumbency and did not prevent the oc-
currence of significant sodium retention
in the upright posture.  however, lack
of adh (in diabetes insipidus) delayed
the antidiuresis upright for 30 minutes.
the results indicate that adh release
is probably responsible for the reduction
in urine volume during the first 30 min-
utes after assuming the upright posture,
but not thereafter.  the excessive magni-
tude of the orthostatic antidiuresis in
idiopathic edema probably results from
a cause other than adh release, since it
is not completely overcome by ethanol.
reduced na excretion during 2 hours in
the upright posture can occur in the
absence of circulating aldosterone, but
the abnormal magnitude of the na re-
tention in the patients with idiopathic
edema probably results from hyperal-
dosteronism.
