Effect of impact exercise on bone metabolism.

SUMMARY: Regular impact exercise in premenopausal women caused positive osteogenic effects associated to low basal serum parathormone (PTH) but had no effects on bone turnover markers PINP or TRACP5b. The low serum basal PTH levels during impact exercise may be a sign of increased incorporation of calcium to bone. INTRODUCTION: This study aimed to determine the long-term effects of high-impact exercise on bone turnover and calciotropic hormones. METHODS: We performed a 12-month population-based, randomized, controlled exercise trial in 120 women (age 35-40 years) randomly assigned to an exercise group (EG; n = 60) or a control group (CG; n = 60). The exercise regimen consisted of supervised high-impact exercises three times per week. Daily impact loading was assessed by using an accelerometer. Bone turnover markers and calciotropic hormones were analyzed at 0, 6, and 12 months. RESULTS: Twelve months of impact exercise did not reveal any treatment effects in bone turnover markers PINP or TRAPC5b, whereas serum basal PTH decreased significantly more in the EG than in the CG (-11.2 vs. -2.2 pg/mL; p = 0.03). The change in PTH was dose dependent and most clearly seen in subjects with 96 to 130 daily impacts at 2.5 to 5.3 g (e.g., running or jumping). CONCLUSIONS: Regular impact exercise does not cause persistent alterations in bone turnover emphasizing necessity of continuous training to achieve bone benefits. Impact exercise training lowers the serum basal PTH levels and possibly enables greater difference between the basal PTH and transient exercise-induced PTH peaks leading to osteogenic effects.

A Bartter-like syndrome after jejunoileal bypass for obesity.

A case of an adult woman with a Bartter-like syndrome after jejunoileal bypass for obesity is described. Diarrhoea, hypokalaemia, high plasma renin activity, hyperaldosteronism, alkalosis, increased urinary prostaglandin E and hyperplasia of the juxtaglomerular apparatus with low or normal blood pressure were the major features. After corrective surgery the values turned only transiently towards normal, despite permanent disappearance of the diarrhoea. Spironolactone, amiloride or propranolol had no real effect on clinical symptoms or biochemical aberrations. Indomethacin, a prostaglandin synthetase inhibitor, normalized most of the aberrations, but--inexplicably--not the prostaglandinuria.

Amniotic fluid beta-2-microglobulin in normal and complicated pregnancies. Correlation with gestational age, creatinine concentration and L/S ratio.

The beta-2-microglobulin concentrations in 127 aminotic fluid samples, obtained during weeks 32-42 of normal pregnancies (n = 58) and complicated pregnancies (n = 69), were measured and correlated with gestational weeks, amniotic fluid creatinine concentrations and L/S ratios. A significant (p less than 0.001) decrease of beta-2-microglobulin concentration occurred from week 32 to 34 of normal pregnancies, after which the beta-2-microglobulin level was unchanged. There were no significant correlations between beta-2-microglobulin concentrations and amniotic fluid creatinine concentrations of LK/S ratios. The beta-2-microglobulin content was elevated in samples obtained from diabetic and toxemic pregnancies. Measurement of beta-2-microglobulin in amniotic fluid seems to be of limited value for determining fetal age, but it may be useful in estimating fetal renal maturity.

The effect of oral thyrotropin-releasing hormone on thyroid function and the composition of breast milk in puerperal women.

To determine the effect of oral administration of thyrotropin-releasing hormone (TRH) on the thyroid function and on the composition of breast milk in the early puerperium, six lactating women were treated with a single dose of 40 mg of synthetic TRH and six women were treated with placebo. Serial serum samples taken before and between one and 25 hours after TRH administration were assayed with specific radioimmunoassays for thyrotropin (TSH), triiodothyronine (T3) and total thyroxine (T4). Milk samples were collected three times a day and their major fatty acids were determined by gas-liquid chromatography and were compared with those obtained from normal lactating women. A statistically significant TSH elevation was observed between one and six hours after TRH administration, with a peak value of 23.7 +/- 10.6 mU/liter at three hours. The T3 concentration rose between three and nine hours after TRH administration, with a peak of 6.3 +/- 1.2 nmole/liter at six hours. The T4 elevation was statistically significant between six and 12 hours after TRH administration. The fatty acid content of milk samples from women treated with TRH did not differ from the normal series. A single daily dose of oral TRH thus caused a temporary thyroid stimulation. It is doubtful whether this could lead to hyperthyroidism since the levels of thyroid hormones became normal within ten hours after TRH administration.

Effects of ritodrine and isoxsuprine with and without dexamethasone during late pregnancy.

beta-Adrenergic agents are used to inhibit preterm labor and glucocorticoids to accelerate fetal pulmonary maturation. A study was designed to investigate the metabolic effects of intravenous infusion of ritodrine (150 to 100 microgram/min) or isoxsuprine (200 to 150 microgram/min) in a series of 28 patients with gestations of 28 to 40 weeks, with and without concomitant dexamethasone therapy. Ritodrine was more potent than isoxsuprine in increasing the circulating levels of cyclic AMP, glucose, insulin, and triglycerides. The diabetogenic effect of both ritodrine and isoxsuprine was so slight that it did not have any clinical significance in women with normal glucose tolerance. The results were similar when these beta-adrenergic tocolytics were given to women concomitantly with intramuscular dexamethasone therapy, although dexamethasone appeared to minimally impair carbohydrate metabolism. Both ritodrine and isoxsuprine caused a significant fall in serum iron and potassium, and this effect was unaltered by dexamethasone. Serial serum potassium levels should be obtained during long-term infusion of beta-mimetics.

Effects of intravenous isoxsuprine and ritodrine, with and without concomitant dexamethasone, on fetoplacental and pituitary hormones and cyclic adenosine monophosphate during late pregnancy.

Beta sympathomimetic drugs are used to inhibit preterm labor and glucocorticoids to accelerate fetal pulmonary maturation. A study was designed to investigate the hormonal effects of intravenous infusion of isoxsuprine 150 to 200 mcg. per minute or ritodrine 100 to 150 mcg. per minute in a series of 28 women at 28 to 40 weeks' gestation, with and without concomitant dexamethasone therapy. Serial serum samples taken before and during the six hours of infusion were assayed for cyclic adenosine-3,5-monophosphate (AMP), estradiol, estriol, progesterone, human placental lactogen (hPL), thyrotropin (TSH), follicle-stimulating hormone (FSH), and human growth hormone (gGH). Ritodrine was more potent than isoxsuprine in increasing the circulating levels of cyclic AMP. The levels of placental steroid hormones decreased slightly, as did the ratio of progesterone to estradiol. Human placental lactogen and pituitary hormones showed no consistent changes. Simultaneous administration of dexamethasone did not modify these results.

ACTH levels in maternal, fetal and neonatal plasma after short-term prenatal dexamethasone therapy.

The effect of prenatal dexamethasone therapy (12, 8 and 4 mg doses given intramuscularly on three consecutive days) on ACTH levels in maternal plasma (n=33), mixed umbilical cord plasma (n=31) and plasma from the newborn (n=29) was studied, and the results were compared with those obtained in 56 healthy parturients and 50 of their newborn. Maternal ACTH after delivery was significantly lower in the mothers treated with dexamethasone than in the control group. Cord ACTH values were similar in the two groups. ACTH levels fell during the early neonatal period, but only at 12 to 24 hours were the ACTH levels significantly lower in the dexamethasone group than in the controls. Gestational age, birth weight and the interval between the dexamethasone therapy and delivery had no significant effect on cord ACTH levels. Short-term prenatal dexamethasone therapy seemed to have very little effect on ACTH secretion in the mother, in the fetus and in the newborn.

Adrenocorticotrophic hormone during the first day of life.

The plasma concentration of ACTH (by radioimmunoassay) was measured in 56 healthy parturients and their newborns. Umbilical cord and maternal venous blood were collected immediately after delivery. In addition one venous blood sample was taken from 50 newborns at the age of 15, 30, 60 min, 2, 6, 12, or 24 h. The maternal and cord plasma ACTH levels were higher than the levels in healthy nonpregnant women. There are no differences between the mean maternal (226 +/- 146 pg/ml) and cord (226 +/- 147 pg/ml) values of ACTH. The high ACTH levels of cord plasma remain unchanged for 30 min, decrease significantly during the 1-6 h after birth, because of the elimination process of the circulated foetal ACTH, and increase over the next 12-24 h and slightly thereafter indicating an initiation of neonatal pituitary ACTH secretion. The plasma ACTH level in the mothers with membranes ruptured for 1-5 h was significantly (P less than 0.05) higher compared with that in the mothers with membranes ruptured for less than 1 h. However, the duration of ruptured membranes appeared to have no effect on the cord blood ACTH level.

ACTH levels in amniotic fluid during pregnancy.

The fetal pituitary-adrenal axis plays an important role in the role in the regulation of fetal development. In order to obtain information about fetal ACTH secretion at different gestational ages, a total of 109 amniotic fluid ACTH determinations was performed by radioimmunoassay. There was a significantly higher level of ACTH during 26 to 30 weeks of pregnancy (429 +/- 180-4 pg/ml) than in early (208-7 +/- 90-6 pg/ml) and in late (172-7 +/- 97-4 pg/ml) pregnancy; fetal sex, uterine contractions and maternal complications in pregnancy did not affect levels. The ACTH level in the first urine of six newborn infants (160-0 +/- 40-6 pg/ml) approximated to that in the amniotic fluid in late pregnancy. Our results support the assumption of a fetal origin for ACTH in amniotic fluid. The high secretion of ACTH at the beginning of the last trimester of pregnancy may stimulate the development of the adrenal cortex and result in the increased cortisol secretion necessary for fetal lung maturation.

Comparison between serum estriol and urinary estrogens as indices of fetoplacental function.

In order to compare the predictive efficacies of serum estriol and urinary estrogen excretion in early diagnosis of fetal distress, 255 patients with normal (N = 128) or complicated (N = 127) pregnancies were monitored with simultaneous determinations of serum estriol (radioimmunoassay) and urinary estrogen excretion/24 h (colorimetric method) after the 32nd week of pregnancy. There was no difference in the efficacies of these tests. Out of all 43 fetal distress cases, 40% were predicted by serum estriol and 33% urinary estrogens. In pre-eclampsia, the respective findings were 56% and 50%. Fetal distress was the most probable (88%) when both of the tests were low at the same time. In pregnancies complicated with diabetes or rhesus immunization both tests revealed normal findings apart from the presence of fetoplacental dysfunction. The choice between these tests must be based on other factors than the diagnostic accuracy.

The effect of labour on ACTH and cortisol levels in amniotic fluid and maternal blood.

Levels of adrenocorticotrophic hormone (ACTH) and cortisol were measured in amniotic fluid during labour and in maternal blood during and after labour. There was a significant rise of maternal ACTH and cortisol levels during labour and a significant decrease after delivery in all 14 patients studied. There were no significant changes in amniotic fluid ACTH and cortisol levels during labour. The initial level of ACTH in amniotic fluid (162-7 pg/ml) was higher than that in maternal circulation (120-2 pg/ml). The correlation between maternal and amniotic fluid ACTH was not significant while the corresponding correlation for cortisol values was.

The effect of electric convulsion therapy on the circulating concentrations of pituitary hormones, cortisol and cyclic adenosine monophosphate.

In order to evaluate the effect of electroconvulsive therapy on the human pituitary-adrenal function, serial plasma samples were assayed for FSH, LH, TSH, HGH, ACTH, cortisol and cyclic AMP before and after nine shocks in five subjects. A prominent finding was the rapid stimulation of the ACTH-cortisol production in all subjects, while no consistent changes in FSH, LH, TSH, HGH or cyclic AMP were found.

Follicle stimulating hormone, thyrotrophin, human growth hormone and prolactin in hyperemesis gravidarum.

To investigate the functional capacity of the anterior pituitary gland in hyperemesis gravidarum, the serum levels of follicle stimulating hormone (FSH), thyrotrophin (TSH), human growth hormone (HGH) and prolactin were measured before and after the combined administration of gonadotrophin and thyrotrophin releasing hormones, (GnRH, TRH), and insulin in seven normal pregnancies, nine with hyperemesis and eight nonpregnant subjects. There was no difference between normal pregnancy and hyperemesis for FSH and TSH, but the basal level of HGH was lower and that of prolactin higher in hyperemesis although their responses following stimulation were similar. Thus there seems to be no hypofunction of the anterior pituitary gland in hyperemesis gravidarum.

The placental and fetal response to the intra-amniotic injection of prostaglandin F2alpha in midtrimester abortions.

The placental and fetal response to the intra-amniotic injection of prostaglandin F2alpha (PGF2alpha) for midtrimester abortions was evaluated. Maternal blood samples for radioimmunological determinations of serum progesterone, human placental lactogen (HPL) and alpha-fetoprotein (AFP) were taken before and serially until 24 hours after the injection of 40 mg (nine patients) or 75 mg (seven patients) of PGF2alpha. Fetal heart action was monitored ultrasonically during the same period. The average induction-abortion interval was 22-6 hours and was indepedent of the dose of PGF2alpha used. The mean progesterone and HPL levels showed a significant fall half an hour after PGF2alpha. The constant decreases began only at 5 hours and later. The mean AFP levels increased rapidly after 5 hours following injection of PGF2alpha. The feral heart stopped at a mean of 10-4 hours (range 0-5 to 25 hours) after the injection of PGF2alpha. No relationship between the time of fetal death or rises in AFP and the induction-abortion interval could be detected. The primary hormonal response of the placenta and the efficacy of exogenous PGF2alpha were not related, indicating the possibility that the abortifacient property of PGF2alpha is not related to its primary effect on placental hormone synthesis or release.

The function of the anterior pituitary-adrenal cortex axis in hyperemesis gravidarum.

In order to study the function of the pituitary-adrenal axis, serum ACTH and cortisol levels were estimated before and after insulin induced hypoglycaemia in nine women with hyperemesis gravidarum, seven women in normal early pregnancy and in eight non-pregnant controls. Before hypoglycaemia, the basal ACTH level in the hyperemesis group (102-4+/-62-9 pg/ml) was higher than in normal early pregnancy (67-5+/-19-2 pg/ml; p less than 0-05) or in non-pregnant controls (54-8+/-25-2 pg/ml; less than 0-01). Correspondingly, the mean cortisol value in hyperemesis (0-47+/-0-16 mumol/l) was higher than in normal early pregnancy (0-39+/-0-10 mumol/l; p greater than 0-05) or in non-pregnant controls (0-32+/-0-13 mumol/l; p less than 0-01). After insulin the elevation of ACTH (p greater than 0-05) and cortisol (p less than 0-01) was observed in every group. The level of ACTH and cortisol was highest in hyperemesis group. Our results do not support the idea that hypofunction of the pituitary-adrenal axis contributes to the aetiology or pathogenesis of hyperemesis gravidarum. The high ACTH level might be evidence of the psychia instability of hyperemesis gravidarum patients.

Serum tri-iodothyronine, thyroxine, and thyrotrophin concentrations in newborns during the first 2 days of life.

The serum concentrations of tri-iodothyronine (T3), thyroxine (T4), and thyrotrophin (TSH) were measured in 10 term newborn infants between birth and the age of 2 days by radioimmunoassay. The mean concentration of T3 in maternal serum was 1.62 mug/l, and it increased from the low cord blood level of 0-63 mug/l to the peak value of 1-76 mug/l within the first 2 hours of life. Mean serum T4 concentrations increased from the cord blood level of 145 mug/l to the peak value of 205 mug/l within the first 24 hours of life. The postnatal increase of the mean serum TSH concentrations from the cord blood level of 5-7 mU/l to the peak value of 20-6 mU/l within 2 hours was similar to the increase of T3. These data confirm earlier reports which show that T3 secretion is low at birth and TSH secretion is stimulated strongly but transiently after birth, and that the low T3 secretion is rapidly normalized in 2 hours along with the TSH release. Because of these strong and rapid changes, we recommend screening of the function of the pituitary-thyroid axis in neonates after the age of 24 hours.