RELATIONSHIP BETWEEN LAMB BIRTH WEIGHTS AND FETAL PLASMA GROWTH HORMONE AND INSULIN CONCENTRATIONS

1986 ◽  
Vol 66 (4) ◽  
pp. 995-1001
Author(s):  
G. J. MEARS
Keyword(s):  
Growth Hormone ◽  
Fetal Growth ◽  
Plasma Insulin ◽  
Plasma Concentrations ◽  
Maternal Plasma ◽  
Metabolic Clearance ◽  
Plasma Growth Hormone ◽  
Fetal Plasma ◽  
Plasma Gh ◽  
Ovine Fetal

Plasma concentrations of growth hormone (GH) and insulin were monitored in 11 chronically cannulated ovine fetuses and their mothers during the last month of gestation to obtain information on the role that these hormones have in determining fetal growth rate. Maternal plasma GH and insulin concentrations were independent of stage of gestation and lamb birth weights. Fetal plasma insulin concentrations were episodic in nature, independent of stage of gestation, and tended to be higher in fetuses that were heavier at birth. Fetal plasma GH concentrations were only slightly episodic in nature, were tenfold higher than maternal levels at 116–124 d gestation and increased by approximately another 25% prior to parturition. Fetal plasma GH concentrations were negtively correlated with lamb birth weights. In twin preparations, fetal plasma GH concentrations were significantly lower in the twin that was heaviest at birth. The lower GH concentrations found in faster growing fetuses are suggestive of a more rapid metabolic clearance of GH by the tissues of these animals. The results indicate that circulating fetal GH and, possibly, insulin are involved in determining the rate of ovine-fetal growth. Key words: Ovine birth weights, fetal GH, fetal insulin, fetal growth

scholarly journals Treatment of underfed pigs with GH throughout the second quarter of pregnancy increases fetal growth

2000 ◽  
Vol 166 (1) ◽  
pp. 227-234 ◽  
Author(s):  
KL Gatford ◽  
JA Owens ◽  
RG Campbell ◽  
JM Boyce ◽  
PA Grant ◽  
...  
Keyword(s):  
Fetal Growth ◽  
Plasma Glucose ◽  
Plasma Concentrations ◽  
Amino Nitrogen ◽  
Live Weight ◽  
Maternal Plasma ◽  
Gh Treatment ◽  
Fetal Plasma ◽  
Nitrogen Concentrations ◽  
Ad Libitum Intake

Circulating growth hormone (GH) concentrations increase in pregnancy and administration of GH during early-mid pregnancy increases fetal growth in well-fed pigs. To determine whether increased maternal GH could promote fetal growth when feed availability is restricted, fifteen cross-bred primiparous sows (gilts) were fed at approximately 30% of ad libitum intake, from mating onwards and were injected daily i.m. with recombinant porcine GH (pGH) at doses of 0, 13.4+/-0.3 and 25.6+/-0.5 microg/kg live weight from day 25 to day 51 of pregnancy (term approximately 115 days). Treatment with pGH increased maternal backfat loss between day 25 and day 51 of pregnancy, and increased maternal plasma IGF-I concentrations measured at day 51 of pregnancy. Fetal body weight, length and skull width at day 51 of pregnancy were increased by maternal treatment with pGH. Fetal plasma glucose concentrations were increased and maternal/fetal plasma glucose concentration gradients were decreased by maternal pGH treatment at 13.4, but not 25.6 microg/kg.day. Fetal plasma concentrations of urea were decreased by both levels of pGH treatment. Overall, fetal weight was negatively correlated with fetal plasma concentrations of urea, positively correlated with maternal plasma alpha-amino nitrogen concentrations and unrelated to glucose concentrations in either maternal or fetal plasma. This suggests that the availability of amino acids, not glucose, limits fetal growth in the first half of pregnancy in underfed gilts, and that maternal GH treatment may improve amino acid delivery to the fetus.

Diurnal variations in plasma concentrations of cortisol, prolactin, growth hormone and glucose in the fetal sheep and pregnant ewe during late gestation

1987 ◽  
Vol 114 (1) ◽  
pp. 65-72 ◽  
Author(s):  
I. C. McMillen ◽  
G. D. Thorburn ◽  
D. W. Walker
Keyword(s):  
Diurnal Rhythm ◽  
Plasma Cortisol ◽  
Plasma Concentrations ◽  
Maternal Plasma ◽  
Diurnal Variations ◽  
Plasma Prolactin ◽  
Fetal Sheep ◽  
Fetal Plasma ◽  
Pregnant Ewe ◽  
Plasma Gh

ABSTRACT We have measured fetal and maternal plasma concentrations of cortisol, prolactin, GH and glucose in samples collected during a 24-h period in 14 animals between 127 and 142 days of gestation. There was a significant increase in both the mean daily plasma cortisol concentration and mean daily coefficient of variation (C.V.) of plasma cortisol concentrations after 135 days of gestation. There was also a significant variation in the fetal plasma cortisol concentrations with a peak occurring at 19.00 h. There was a significant sinusoidal diurnal rhythm in the plasma prolactin concentrations in both the fetal sheep and pregnant ewe and the maximal prolactin concentrations occurred between 19.00 and 23.00 h (fetal) and 21.00 and 01.00 h (maternal). Although no significant diurnal variation was detected in fetal plasma GH concentrations, there was a significant sinusoidal diurnal rhythm in the plasma GH concentrations of the pregnant ewe and the maximal maternal GH concentrations occurred between 21.00 and 01.00 h. Both the fetal and maternal plasma glucose concentrations showed a significant sinusoidal diurnal rhythm. The maximal maternal and fetal glucose concentrations were measured between 21.00 and 01.00 h and between 23.00 and 03.00 h respectively. We have therefore established that diurnal variations in plasma cortisol and prolactin concentrations exist prenatally. Whether the presence of such hormonal rhythms reflects the activity of an endogenous fetal circadian pacemaker remains to be established. J. Endocr. (1987) 114, 65–72

Influence of feeding and diet on diurnal patterns of plasma growth hormone and insulin in calves

1993 ◽  
Vol 73 (4) ◽  
pp. 987-991 ◽  
Author(s):  
G. J. Mears
Keyword(s):  
Growth Hormone ◽  
Plasma Insulin ◽  
Feeding Time ◽  
Elevated Plasma ◽  
Plasma Growth Hormone ◽  
Diurnal Patterns ◽  
Newborn Calves ◽  
Meal Feeding ◽  
Plasma Gh ◽  
Diet Type

Plasma GH concentrations were lower after feeding than before (newborn calves, P < 0.05; steers, P < 0.01). Calves fed concentrate had higher plasma insulin concentrations than those fed hay (P < 0.01). Meal feeding milk or concentrate, but not hay, elevated plasma insulin (P < 0.05). Diet type and feeding time relative to sampling time must be considered when measuring GH and insulin. Key words: Diurnal patterns, growth hormone, GH, insulin, calves

Acute ethanol exposure in pregnancy alters the insulin-like growth factor axis of fetal and maternal sheep

2007 ◽  
Vol 292 (2) ◽  
pp. E494-E500 ◽  
Author(s):  
Kathryn L. Gatford ◽  
Penelope A. Dalitz ◽  
Megan L. Cock ◽  
Richard Harding ◽  
Julie A. Owens
Keyword(s):  
Fetal Growth ◽  
Plasma Concentrations ◽  
Maternal Plasma ◽  
Ethanol Exposure ◽  
Growth Restriction ◽  
Fetal Plasma ◽  
Pregnant Sheep ◽  
Before And After ◽  
Acute Ethanol ◽  
Igf Binding

Maternal ethanol intake during pregnancy impairs fetal growth, but mechanisms are not clearly defined. Reduced IGF abundance or bioavailability in the fetus and/or mother may contribute to this growth restriction. We hypothesized that an episode of acute ethanol exposure, mimicking binge drinking would restrict fetal growth and perturb the maternal and fetal IGF axes. Pregnant sheep were infused intravenously with saline or ethanol (1 g/kg maternal wt) over 1 h, on days 116, 117, and 118 of gestation (start of 1st infusion = time 0, term is 147 days). Maternal and fetal plasma IGF and IGF-binding protein (IGFBP) concentrations were measured before and after each infusion. Compared with controls, ethanol exposure reduced fetal weight at day 120 by 19%, transiently reduced maternal plasma IGF-I (−35%) at 30 h, and decreased fetal plasma IGF-II (−28%) from 24 to 54 h after the first infusion. Ethanol exposure did not alter maternal or fetal plasma concentrations of IGFBP-2 and IGFBP-3, measured by Western ligand blotting. We conclude that suppression of maternal and fetal IGF abundance may contribute to fetal growth restriction induced by acute or binge ethanol exposure.

scholarly journals Enhanced Nitrite-Mediated Relaxation of Placental Blood Vessels Exposed to Hypoxia Is Preserved in Pregnancies Complicated by Fetal Growth Restriction

2021 ◽  
Vol 22 (9) ◽  
pp. 4500
Author(s):  
Teresa Tropea ◽  
Carina Nihlen ◽  
Eddie Weitzberg ◽  
Jon O. Lundberg ◽  
Mark Wareing ◽  
...  
Keyword(s):  
Blood Flow ◽  
Blood Vessels ◽  
Fetal Growth ◽  
Fetal Growth Restriction ◽  
Plasma Concentrations ◽  
Growth Restriction ◽  
Alternative Source ◽  
Fetal Plasma ◽  
Placental Blood ◽  
Nitrate And Nitrite

Nitric oxide (NO) is essential in the control of fetoplacental vascular tone, maintaining a high flow−low resistance circulation that favors oxygen and nutrient delivery to the fetus. Reduced fetoplacental blood flow is associated with pregnancy complications and is one of the major causes of fetal growth restriction (FGR). The reduction of dietary nitrate to nitrite and subsequently NO may provide an alternative source of NO in vivo. We have previously shown that nitrite induces vasorelaxation in placental blood vessels from normal pregnancies, and that this effect is enhanced under conditions of hypoxia. Herein, we aimed to determine whether nitrite could also act as a vasodilator in FGR. Using wire myography, vasorelaxant effects of nitrite were assessed on pre-constricted chorionic plate arteries (CPAs) and veins (CPVs) from normal and FGR pregnancies under normoxic and hypoxic conditions. Responses to the NO donor, sodium nitroprusside (SNP), were assessed in parallel. Nitrate and nitrite concentrations were measured in fetal plasma. Hypoxia significantly enhanced vasorelaxation to nitrite in FGR CPAs (p < 0.001), and in both normal (p < 0.001) and FGR (p < 0.01) CPVs. Vasorelaxation to SNP was also potentiated by hypoxia in both normal (p < 0.0001) and FGR (p < 0.01) CPVs. However, compared to vessels from normal pregnancies, CPVs from FGR pregnancies showed significantly lower reactivity to SNP (p < 0.01). Fetal plasma concentrations of nitrate and nitrite were not different between normal and FGR pregnancies. Together, these data show that nitrite-mediated vasorelaxation is preserved in FGR, suggesting that interventions targeting this pathway have the potential to improve fetoplacental blood flow in FGR pregnancies.

Premature birth of live lambs induced by pulsatile infusion of ACTH

1990 ◽  
Vol 124 (1) ◽  
pp. 99-107 ◽  
Author(s):  
R. J. MacIsaac ◽  
R. S. Carson ◽  
A. P. Horvath ◽  
E. M. Wintour
Keyword(s):  
Plasma Concentrations ◽  
Maternal Plasma ◽  
Sampling Time ◽  
Plasma Acth ◽  
Fetal Plasma ◽  
A Value ◽  
Normal Term ◽  
Acth Treatment ◽  
Normal Gestation ◽  
Pulsatile Infusion

ABSTRACT This study was designed to investigate the effects of pulsatile infusion of ACTH into ovine fetuses on the endocrine changes that precede parturition, the timing of birth and the subsequent survival of the lamb. Where appropriate, these parameters were compared with fetuses infused with pulses of saline and uninfused normal term fetuses. Ten fetuses received a 15-min infusion of synthetic ACTH(1–24) (79 ng/min) from day 125 (n=9) or day 126 (n=1) of gestation. Seven fetuses were born prematurely within 174±14 h (mean ± s.e.m.) after the commencement of the infusion, i.e. at 132 ± 0·6 days, whilst three died in utero at 130–131 days. When born all lambs could breath, walk and suckle. Of the seven premature lambs, four died 2–10 days after parturition but three survived for at least 12 months after birth. Fetuses infused with pulses of ACTH exhibited intermittent but very large increases in plasma ACTH values, with the first pulse, on day 1, increasing ACTH values from 5·1 ± 1·1 to 140 ± 31·3 pmol/l (P<0·001). At the next sampling time, ACTH values were not significantly different from preinfusion values. A similar plasma ACTH profile was observed on each subsequent day of ACTH treatment. In contrast, fetuses (n=4) infused with pulses of saline between 125 and 131 days exhibited fetal plasma concentrations of ACTH which ranged between 2 and 12 pmol/l for the majority of the time. Of the uninfused fetuses (n=8) that were studied during the last week of normal gestation, seven were born alive at 148·9± 1·0 days of gestation, whilst one lamb was stillborn at 146 days. In these fetuses, plasma concentrations of ACTH increased slowly to 35·6 ±2·4 pmol/l on the day before delivery with a further increase to 76·4± 3·9 pmol/l occurring on the day of delivery. In fetuses infused with pulses of ACTH there was also a significant (P< 0·001) increase in the fetal cortisol to corticosterone ratio from a value of 2·9 before the commencement of the infusion to 69·1 just before birth. In ewes bearing uninfused fetuses born at normal term, maternal plasma concentrations of progesterone on day 4 before delivery were significantly (P<0·05) lower than on day 5 before delivery. In comparison, in ewes bearing fetuses infused with pulses of ACTH, a significant (P<0·05) decrease from maternal plasma concentrations of progesterone on day 5 before delivery did not occur until day 1 before delivery. In ewes bearing uninfused or prematurely delivered fetuses infused with pulses of ACTH, maternal plasma concentrations of oestrogen did not significantly (P<0·01) increase until the day of parturition. It is concluded that a minimum of 6–7 days of ACTH treatment is required by the fetal adrenal for the induction of cortisol synthesis sufficient to produce the birth of viable lambs. However, premature lambs have a 57% mortality rate in the 2- to 10-day period after birth. Journal of Endocrinology (1990) 124, 99–107

PITUITARY FUNCTION AFTER YTTRIUM IMPLANTS AS MEASURED BY PLASMA GROWTH HORMONE LEVELS

1971 ◽  
Vol 50 (1) ◽  
pp. 41-50 ◽  
Author(s):  
HELEN J. STEWART ◽  
E. A. BENSON ◽  
M. MAUREEN ROBERTS ◽  
A. P. M. FORREST ◽  
F. C. GREENWOOD
Keyword(s):  
Breast Cancer ◽  
Growth Hormone ◽  
Advanced Breast Cancer ◽  
Adrenal Function ◽  
Advanced Breast ◽  
Pituitary Function ◽  
Post Mortem ◽  
Plasma Growth Hormone ◽  
Fasting Level ◽  
Plasma Gh

SUMMARY Plasma growth hormone (GH) levels during insulin hypoglycaemia were measured in 30 women with implants of 90Y in the pituitary for advanced breast cancer. There was evidence of continued pituitary activity in six patients (20%), the rise in plasma GH level being greater than 4 ng/ml during hypoglycaemia. Thirteen patients (43%) were regarded as having complete ablations because they had no GH response and a fasting level of less than 4 ng/ml. In the remaining 11 patients (37%) there was no rise in the GH level during hypoglycaemia, but there were significant fasting levels. From the post-mortem evidence it was concluded that these patients also had adequate ablations. This test is shown to be of more value in estimating residual pituitary function than routine tests of thyroid or adrenal function.

Thyroid and parathyroid-independent increase in plasma 1,25-dihydroxyvitamin D during late pregnancy in the rat

1988 ◽  
Vol 116 (3) ◽  
pp. 381-385 ◽  
Author(s):  
T. M. Nguyen ◽  
A. Halhali ◽  
H. Guillozo ◽  
M. Garabedian ◽  
S. Balsan
Keyword(s):  
Vitamin D ◽  
Placental Transfer ◽  
Plasma Concentrations ◽  
Late Pregnancy ◽  
Maternal Plasma ◽  
Vitamin D Metabolites ◽  
Pregnant Rats ◽  
Dihydroxyvitamin D ◽  
Fetal Plasma ◽  
And Control

ABSTRACT The effect of thyroparathyroidectomy (TPTX) on the plasma concentrations of the vitamin D metabolites (25-(OH)D, 24,25-(OH)2D and 1,25-(OH)2D) has been studied in pregnant rats and their fetuses during the last quarter of gestation. Maternal and fetal vitamin D metabolites were not significantly affected by TPTX. A significant increase in plasma 1,25-(OH)2D concentrations was observed in both TPTX and control mothers and fetuses from days 19 to 21. Fetal and maternal plasma 25-(OH)D were positively correlated in both control and TPTX groups. Such a correlation was also found for 24,25-(OH)2D in the two groups. In contrast, a positive correlation between maternal and fetal plasma concentrations of 1,25-(OH)2D was found in TPTX but not in control rats. These data suggest that major alterations in calcium metabolism, such as that produced by maternal TPTX, are insufficient to affect the changes in maternal and fetal plasma 1,25-(OH)2D during late pregnancy significantly. They also suggest that parathyroid hormone, thyroxine, and/or calcitonin may control a possible placental transfer of 1,25-(OH)2D in the rat. J. Endocr. (1988) 116, 381–385

PLASMA INSULIN AND GROWTH HORMONE CONCENTRATIONS IN PREGNANT SHEEP II:

1976 ◽  
Vol 82 (2) ◽  
pp. 553-560 ◽  
Author(s):  
Anne Kristine Blom ◽  
Knut Hove ◽  
Jon J. Nedkvitne
Keyword(s):  
Growth Hormone ◽  
Plasma Insulin ◽  
Late Pregnancy ◽  
Plasma Free Fatty Acid ◽  
Maternal Metabolism ◽  
Pregnant Sheep ◽  
Significant Difference ◽  
Pregnant Ewe ◽  
Plasma Gh ◽  
Maintenance Ration

ABSTRACT The pregnant ewe compensates the reduced carbohydrate availability in late pregnancy by increased fat combustion. The purpose of the present study was to examine the adaptation of plasma growth hormone (GH) and insulin levels to this change in energy substrate metabolism. Two groups of ewes were bled in the post-absorptive state at different stages of pregnancy. One group (7 animals) was fed adequately throughout pregnancy, while the other received a maintenance ration for non-pregnant sheep (28 animals). Plasma GH increased from averages from 2–3 to 8–14 ng/ml during the last month before lambing. Shearing of the wool combined with a cold stress resulted in a clearly detectable peak in plasma GH in the underfed sheep. No significant difference in plasma GH attributable to differences in diet could be detected in late pregnancy. Plasma insulin decreased steadily the last 5 weeks towards lambing, most in mothers with 3 lambs. Plasma free fatty acid levels (FFA) increased the last 2 months of pregnancy, most in the underfed sheep. GH and FFA were positively correlated (r = 0.50 and 0.30 in the two groups). It is concluded that the adaptation of the maternal metabolism to reduced carbohydrate - and eventually energy-availability in late pregnancy included lowering of insulin and enhancement of plasma GH levels. These adaptations were detectable under the present conditions the last 5–6 weeks before term.

GLUCOSE DISAPPEARANCE RATE IN SYMPTOMATIC NEONATAL HYPOGLYCEMIA

PEDIATRICS ◽  
1973 ◽  
Vol 52 (1) ◽  
pp. 75-82
Author(s):  
Rosita S. Pildes ◽  
Daksha A. Patel ◽  
Menachem Nitzan
Keyword(s):  
Growth Hormone ◽  
Plasma Insulin ◽  
Newborn Infants ◽  
Glucose Disposal ◽  
Disappearance Rate ◽  
Neonatal Hypoglycemia ◽  
Plasma Growth Hormone ◽  
Intravenous Glucose ◽  
Glucose Disappearance

The present study was undertaken to determine the rate of glucose disposal in the pathogenesis of symptomatic neonatal hypoglycemia. Intravenous glucose (1 gm/kg) was injected rapidly into 11 hypoglycemic and eight control newborn infants. The percentage (mean ± SEM) disappearance rate per minute (Kt) was significantly higher (p &lt; 0.001) in the hypoglycemic newborn infants compared with that of the controls (2.8 ± 0.1 versus 1.2 ± 0.1, respectively). Baseline plasma insulin concentrations were significantly higher (p &lt; 0.01) in the hypoglycemic (16.8 ± 3.9µU/ml) than those of the controls (3.5 ± 1.0µU/ml). Baseline plasma growth hormone values in the hypoglycemic newborns were 16.6 ± 5.7 mµg/ml. Growth hormorne values rose in the hypoglycemic to 36 ± 10 mµg/ml at 10 minutes and to 64 ± 13 mµg/ml by 60 minutes.

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