The Effects of Estradiol and Estriol on Plasma Levels of Cortisol and Thyroid Hormone-Binding Globulins and on Aldosterone and Cortisol Secretion Rates in Man*

101

A B S T R A C T Aldosterone concentrations in plasma of women on normal sodium intake undergoing cesarean section were 3.7 ±1.4 ng/100 ml (mean ±1 SD). These values were significantly lower (P <0.001) than those observed in mothers on normal sodium diet, delivered by the vaginal route (14.9 +7.0 ng/100 ml). A significant elevation (P < 0.001) of the concentrations was found if the mothers had been on sodium restriction and/or diuretics (44.9 ±24.2 ng/100 ml). In supine position, adult nonpregnant subjects have aldosterone concentrations in plasma of 1.7 ±1.4 ng/100 ml on normal sodium intake and of 16.7 ±8.1 ng/100 ml on low sodium diet.Simultaneous determinations of aldosterone levels in cord blood showed that cord values were significantly higher than those of the corresponding mother (P < 0.01 by paired t test). However, values in cord blood of infants born to mothers on a normal sodium intake were significantly lower (P < 0.005) than those of infants whose mothers had required low sodium diet and/or diuretics during their pregnancy.Aldosterone concentrations in plasma of infants 1-72 hr of age and born to mothers on normal sodium intake were 25.9 ±11.7 ng/100 ml (mean ±1 SD). These values were significantly lower (P < 0.005) than those of infants born to mothers on restricted sodium intake with or without diuretics (80.3 ±54.4 ng/100 ml). The concentrations at birth were not significantly different from those observed during the first 3 days of life (P>0.6).

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Plasma Aldosterone Concentration at Delivery and during the Newborn Period

Beitins¹,

Bayard²,

Levitsky³

et al. 1972

101

“…Humoral agents, such as progesterone, angiotensin, and estrogen may affect renal salt handling (39)(40)(41)(42). Physical factors also must be considered.…”

Section: Discussionmentioning

confidence: 99%

Effect of hypotonic expansion on sodium, water, and urea excretion in late pregnancy: the influence of posture on these results

Lindheimer¹,

Weston²

1969

A B S T R A C T Mineralocorticoid-treated, normotensive third trimester subjects positioned in lateral recumbency were studied before and during the infusion of 300 mEq of hypotonic saline. Urinary sodium excretion increased in all subjects from a mean value of 199 to 416 IAEq/min.In 12 maximally hydrated subjects free water clearance (CH2o) and urine flow (V) increased from means of 7.54 and 9.50 to 11.6 and 14.5 ml/100 ml of glomerular filtrate (GFR) Also the ratio of urea to inulin clearance (Curen/Cinuiln) increased from 0.59 to 0.64. The changes in the renal handling of water and urea suggest that fractional sodium reabsorption decreased at proximal nephron sites.The subjects then assumed a supine position, and the results were compared to those obtained during the lateral recumbent control periods. Filtered sodium decreased in 11 experiments, but in five studies it remained up to 2.6 mEq/min above control values. There was only one instance in which a significant increase in sodium excretion occurred. It was concluded that supine recumbency blunts natriuresis despite volume expansion or an increase in the filtered load of sodium.Finally, in the 12 hydrated subjects supine recumbency reduced CH2o and V from a mean of 11.6 and 14.5 to 6.2 and 8.2 ml/100 ml of GFR. In eight of these experiPreliminary reports of this work have been published in abstract form:

“…Values for the latter varied widely, some falling within the normal range and others within the range found in normal pregnancy. In these patients measurements of urinary estrogen excretion just before induction of labor, published in detail elsewhere (27), revealed no correlation between the binding capacity of TBG at that time and the excretion of either total estrogens or estrone and estradiol, which are far more potent than estriol in inducing an increase of TBG (28).…”

Section: Thyroid Hormone Economy In Molar Pregnancymentioning

confidence: 71%

Alterations in thyroid hormone economy in patients with hydatidiform mole

Galton¹,

Ingbar²,

Jimenez-Fonseca³

et al. 1971

A B S T R A C T Studies of several aspects of thyroid hormone economy have been conducted in 11 patients before and after removal of a molar pregnancy. Before evacuation of the mole, all patients demonstrated moderately to greatly elevated values for thyroidal 'I uptake, absolute iodine uptake, and serum protein-bound-I. Values for serum PBI and serum thyroxine (T4) concentration were consistently and often greatly increased, averaging more than twice those found in normal pregnancy and three times those in normal controls. On the other hand, the maximum binding capacity of the T4-binding globulin (TBG) was variably affected, and ranged between the values found in normal controls and those found in normal pregnancy. Values for the absolute concentration of free T4 in serum were, on the average, only moderately elevated, since the proportion of free To was moderately low, although not as low as in normal pregnancy. Sera of patients with molar pregnancy contained high levels of thyroid stimulating activity, as assessed in the McKenzie mouse bioassay system. The stimulator displayed a more prolonged duration of action than that of TSH and did not reveal a major immunological cross-reactivity with either human or bovine TSH, differing in the latter respect from the chorionic thyrotropin of normal human placenta. Abnormalities in iodine metabolism were rapidly ameliorated after removal of the molar pregnancy, and this was Despite the foregoing evidence of thyroid hyperfunction and hypersecretion of T4, patients with molar pregnancy were neither goitrous nor overtly thyrotoxic. They did display, however, high values of the urinary pigment/creatinine ratio, a possible indication of the presence of a hypermetabolic state.It is concluded that in patients with molar pregnancy, thyroid function and T4 secretion are stimulated, often greatly so, by an unusual thyroid stimulator which is demonstrable in the blood and which is probably of molar origin. The nature of the stimulator, as well as the reasons for both the variability of the increase in TBG which occurs in molar pregnancy and the lack of frank thyrotoxicosis, remain to be clarified.