Long-term effects of early postnatal food restriction on growth hormone secretion in rats.

Background: Malnutrition in early life retards growth permanently in both humans and rats, but the underlying mechanism is unclear. The purpose of this study was to test the hypothesis that early postnatal food restriction induces long-term changes in the growth hormone-insulin-like growth factor I (GH-IGF-I) axis.

Methods: We examined the effect of increasing litter size to 20 during lactation [food restriction (FR)] on growth and spontaneous GH secretion and serum IGF-I levels in 14- to 15-week-old rats.

Maturity of the adrenal cortex in very preterm infants is related to gestational age.

To study the maturity of the adrenal cortex in preterms born before 33 wk of gestation, basal levels of cortisol and cortisone and the cortisol and 17-hydroxyprogesterone (17-OHP) response to 1 microg/kg adrenocorticotropic hormone stimulation were measured in 24 appropriate-for-gestational age preterm infants (26-33 wk; 690-1985 g). Gestational age influenced the response of cortisol, 17-OHP, and the ratio between cortisol/17-OHP in the studied infants. In preterms born <30 wk of gestation, levels of cortisol, and the ratio between cortisol/17-OHP were lower compared with preterms born between 30 and 33 wk.

Bone metabolism markers and bone mass in healthy pubertal boys and girls.

Objective: During puberty, bone growth and mineralization as well as bone turnover increase dramatically. The relation between height velocity and bone turnover is already known, but there are few studies in which both bone metabolism markers and bone mass throughout puberty have been measured.

Design: Semi-longitudinal study.

Delayed first cycle in intrauterine growth-retarded and postnatally undernourished female rats: follicular growth and ovulation after stimulation with pregnant mare serum gonadotropin at first cycle.

In the present study we examined the consequences of intrauterine growth retardation and postnatal food restriction on the maturational process of sexual development by studying onset of first cycle. In addition, we investigated the effect of pregnant mare serum gonadotropin (PMSG) on ovarian growth and ovulation in intrauterine growth-retarded (IUGR) and postnatally food-restricted (PFR) rats. Intrauterine growth retardation was induced by uterine artery ligation on day 17 of gestation and food restriction was achieved by enlarging the litter to 20 pups per mother from day 2 after birth until weaning (day 24).

Components of the insulin resistance syndrome in seven-year-old children: relations with birth weight and the polyunsaturated fatty acid content of umbilical cord plasma phospholipids.

Aims/hypothesis: According to the foetal origins hypothesis, there is a relation between foetal nutrition and adult glucose intolerance. In adults, insulin resistance has been associated with dietary polyunsaturated fatty acids. We examined whether the availability of polyunsaturated fatty acids during foetal life, as indicated by the fatty acid composition of cord blood samples, relates to childhood body composition and glycaemic control.

Fetal growth and the function of the adrenal cortex in preterm infants.

Small for gestational age preterm infants have a higher risk of neonatal morbidity compared to appropriate for gestational age preterm infants. A diminished adrenal response to stress may be involved in the higher postnatal morbidity. The adrenal cortex response in relation to fetal growth was studied by ACTH stimulation tests in 43 preterm infants (born < or = 32 wk).

Composition of LDL as determinant of its susceptibility to in vitro oxidation in patients with well-controlled type 2 diabetes.

Background: There is increasing evidence that oxidation of low-density lipoprotein (LDL) in the vascular wall plays an important role in the development of atherosclerosis. The present study was undertaken to characterise how different constituents of LDL contribute to its in vitro oxidisability.

Methods: The LDL composition, i.

Determinants of bone mineral density in older men and women: body composition as mediator.

This study aimed to assess the relative importance of several determinants of bone mineral density (BMD) and to examine to what extent these potential determinants influence total hip BMD through body composition. The study population consisted of 522 participants (264 women and 258 men) of the Longitudinal Aging Study Amsterdam (LASA), aged 65 years and over, and living in Amsterdam and its vicinity. BMD of the total hip was measured using dual-energy X-ray absorptiometry (DXA).

Body mass index, body composition, and leptin at onset of puberty in male and female rats after intrauterine growth retardation and after early postnatal food restriction.

In this study we examined the body composition at onset of puberty in intrauterine growth retarded (IUGR), postnatal food restricted (FR), and control male and female rats. IUGR was induced by ligation of the uterine artery on d 17 of gestation and FR by litter enlargement to 20 pups per mother from d 2 after birth until weaning (d 24). We defined onset of puberty as balanopreputial separation in male rats and vaginal opening in female rats.

The effect of exercise on systemic and bone concentrations of growth factors in rats.

Exercise can prevent bone loss and increase bone density. Growth factors such as insulin-like growth factor-I (IGF-I) and transforming growth factor beta (TGFbeta) are thought to be involved in the local response to mechanical loading, resulting in bone remodelling. We tested the effect of additional weight bearing during exercise on the systemic response of IGF-I and local bone response of IGF-I and TGFbeta.

Effects of the selective estrogen receptor modulator, raloxifene, on the somatotropic axis and insulin-glucose homeostasis.

Raloxifene is the first selective estrogen receptor modulator registered for the prevention and treatment of postmenopausal osteoporosis. In addition to direct effects on bone cells, estrogen and raloxifene may act indirectly via changes in hormonal homeostasis. However, the menopause-related decrease in serum insulin-like growth factor I (IGF-I) and the increase in insulin or glucose are not always reversed by estrogen replacement.

Impaired activity of the extraneuronal monoamine transporter system known as uptake-2 in Orct3/Slc22a3-deficient mice.

Two uptake systems that control the extracellular concentrations of released monoamine neurotransmitters such as noradrenaline and adrenaline have been described. Uptake-1 is present at presynaptic nerve endings, whereas uptake-2 is extraneuronal and has been identified in myocardium and vascular and nonvascular smooth muscle cells. The gene encoding the uptake-2 transporter has recently been identified in humans (EMT), rats (OCT3), and mice (Orct3/Slc22a3).

Effects of the selective oestrogen receptor modulator-raloxifene-on calcium and PTH secretory dynamics in women with osteoporosis.

Objectives: A possible mechanism for the maintenance of bone mass by oestrogens and the selective oestrogen receptor modulator (SERM)-raloxifene-is an interaction with calciotropic hormones. We studied the effects of raloxifene on calcium-PTH homeostasis.

Patients And Measurements: Calcium and EDTA infusions were performed in 32 post-menopausal women with osteoporosis (BMD T score < - 2.

The relationship between thyrotropin and low density lipoprotein cholesterol is modified by insulin sensitivity in healthy euthyroid subjects.

High levels of TSH are associated with an increased cardiovascular risk. Many cardiovascular risk factors cluster within the insulin resistance syndrome. It is not known whether levels of TSH cluster as well.

The effects of intra-uterine growth retardation and postnatal undernutrition on onset of puberty in male and female rats.

The nutritional status, prenatally and early postnatally, plays a critical role in postnatal growth and development. Early malnutrition may change the original programming of organs, especially those in developmental phases, which can result in long-term changes in metabolism. The association between a low birth weight and the increased risk on type 2 diabetes, hypertension and cardiovascular disease is well known.

Endocrine regulation and extended follow up of longitudinal growth in intrauterine growth-retarded rats.

Bilateral uterine artery ligation in late gestation was performed in pregnant dams in order to determine the effects of intrauterine growth retardation (IUGR) on long-term postnatal somatic growth and the GH neuroendocrine axis in the adult female and male rat. Body weight (BW), nose-anus length (NAL) and tail length (TL) were recorded at regular intervals in both the IUGR and control (CON) offspring until the age of 93 days. Spontaneous 6-h GH secretory profiles and serum IGF-I were determined around the age of 100 days in both the IUGR and the CON group.

Elevated FSH concentrations in imminent ovarian failure are associated with higher FSH and LH pulse amplitude and response to GnRH.

Imminent ovarian failure (IOF) in women is characterized by regular menstrual cycles and elevated early follicular phase FSH. This study explored underlying neuroendocrine causes of elevated FSH concentrations on day 3 of the menstrual cycle. The characteristics of episodic secretion of FSH and LH, the pituitary response to gonadotrophin-releasing hormone (GnRH), plasma oestradiol, and dimeric inhibin A and inhibin B on day 3 were compared in 13 women with elevated FSH concentrations (>10 IU/l) and 16 controls.

Optimized basal-bolus therapy using a fixed mixture of 75% lispro and 25% NPL insulin in type 1 diabetes patients: no favorable effects on glycemic control, physiological responses to hypoglycemia, well-being, or treatment satisfaction.

Objective: To investigate the effects of a multiple injection regimen with a mixture of 75% lispro and 25% intermediate-acting insulin (lispro high mixture [HM]) before meals on glycemic control, physiological responses to hypoglycemia, well-being, and treatment satisfaction.

Research Design And Methods: We studied 35 type 1 diabetes patients. After an 8- to 10-week lead-in period, patients were randomized to HM or human regular insulin therapy for 12-14 weeks.

Predictors of fractures in elderly women.

In a prospective study of 348 apparently healthy women, aged 70 years and over (mean 80.3 years), we examined bone mineral density (BMD), biochemical markers of bone metabolism, and some easily measurable predictors in relation to hip and osteoporotic fractures. In addition, we constructed risk profiles for hip and osteoporotic fractures.

Bromocriptine-induced premature oestrus is associated with changes in the pulsatile secretion pattern of follicle-stimulating hormone in beagle bitches.

The secretory profiles of LH and FSH were investigated before and during the administration of bromocriptine in six beagle bitches. Plasma samples were obtained via jugular venepuncture at 10 min intervals for 6 h every 2 weeks until the next ovulation. Bromocriptine treatment was started 100 days after ovulation.

Triiodothyronine: a link between the insulin resistance syndrome and blood pressure?

Objective: Overall obesity is associated with elevated serum triiodothyronine concentrations and insulin resistance. Oral triiodothyronine is known to induce hypertension in laboratory rats, while triiodothyronine also increases the expression of genes encoding for enzymes involved in the synthesis and secretion of insulin by pancreatic beta cells. We investigated the hypothesis that central obesity and insulin resistance are linked with an increased blood pressure and insulin production through elevated free serum triiodothyronine concentrations.

Effects of administration of 17beta-oestradiol on serum leptin levels in healthy postmenopausal women.

Objective: Women have higher leptin levels than men at a certain degree of adiposity. The role of oestrogens in the regulation of serum leptin levels remains inconclusive. The aim of the present study was to investigate the effect of unopposed oestrogen replacement therapy, during two months, on serum leptin levels in postmenopausal women.