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.

PLASMA INSULIN AND GROWTH HORMONE CONCENTRATIONS IN PREGNANT SHEEP I:

1976 ◽  
Vol 82 (2) ◽  
pp. 544-552 ◽  
Author(s):  
Knut Hove ◽  
Anne Kristine Blom
Keyword(s):  
Growth Hormone ◽  
Plasma Insulin ◽  
Late Pregnancy ◽  
Plasma Growth Hormone ◽  
Energy Substrate ◽  
Insulin Levels ◽  
Pregnant Sheep ◽  
Plasma Insulin Levels ◽  
Insulin Responses ◽  
Substrate Concentrations

ABSTRACT Two or three foetal lambs regularly result in a varying degree of carbohydrate shortage in mother ewes in late pregnancy. We have investigated the correlation between plasma insulin, growth hormone and energy substrate concentrations in ewes 8 and 1 weeks before lambing. Plasma growth hormone was fairly constant (2–3 ng/ml) throughout the 24-h cycle 8 weeks before parturition. Seven weeks later higher average levels and increased diurnal fluctuations were observed in 3 out of 4 multiparous ewes. The average post-absorptive insulin levels were reduced by 50 per cent during the same interval. Simultaneously decreased post-absorptive sugar and increased acetoacetate levels were observed. It is concluded that the hormonal adaptations to the increasing carbohydrate deficit in late pregnancy, especially among multiparous ewes, include: a) reduced post-absorptive plasma insulin levels, b) reduced insulin responses to feeding, and c) increased levels of growth hormone in the plasma.

Inverse control of growth hormone and prolactin secretion in clonidine-stimulated dairy cattle

1995 ◽  
Vol 146 (2) ◽  
pp. 271-277 ◽  
Author(s):  
V Borromeo ◽  
A Berrini ◽  
F Möller ◽  
C Secchi
Keyword(s):  
Growth Hormone ◽  
Dairy Cattle ◽  
Dairy Cows ◽  
Peak Concentration ◽  
Plasma Insulin ◽  
Prolactin Secretion ◽  
Inverse Control ◽  
Significant Difference ◽  
Plasma Gh ◽  
Plasma Prl

Abstract Clonidine is a specific α-2-adrenoreceptor agonist that stimulates growth hormone (GH) release in animals and humans. This drug was used to study the GH and prolactin (PRL) secretory response in dairy cows and heifers. An i.v. infusion of 10 μg/kg body weight induced GH release to a peak concentration after 30–60 min, while 2 μg/kg had no effect on GH secretory patterns. Plasma PRL decreased significantly (P<0·01) starting 15–60 min after both doses of clonidine, this effect lasting up to 6 h. Clonidine significantly lowered plasma insulin (P<0·01) and raised plasma glucose (P<0·01). The changes in plasma GH, PRL, insulin and glucose differed significantly between doses, the 10 μg/kg dose being more effective (P<0·01). The results of our investigation in dairy cattle provide evidence of (i) an increase in GH release after 10 μg/kg clonidine; (ii) a concomitant decrease in PRL secretion, hence GH and PRL secretion in cattle appear inversely controlled; (iii) a significant difference between the effects of the 2 and 10 μg/kg doses and (iv) no relationship between the changes in plasma GH and PRL after clonidine and plasma hormone levels before treatment. Journal of Endocrinology (1995) 146, 271–277

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

PLASMA INSULIN AND GROWTH HORMONE IN GROWING LAMBS FED MONENSIN

1988 ◽  
Vol 68 (1) ◽  
pp. 165-171 ◽  
Author(s):  
G. J. MEARS ◽  
J. A. VESELY ◽  
K.-J. CHENG
Keyword(s):  
Growth Hormone ◽  
Key Words ◽  
Plasma Insulin ◽  
Average Daily Gain ◽  
Feed Ratio ◽  
Lower Plasma ◽  
Apparent Increase ◽  
Ewe Lambs ◽  
Plasma Gh ◽  
Daily Gain

Plasma insulin and growth hormone (GH) were measured in 62 monensin-treated lambs and 59 control lambs from four experiments that were conducted to determine the effect of monensin treatment on average daily gain (ADG) and gain to feed ratio (G:F). Plasma GH concentrations were lower in lambs that received monensin (P < 0.05–0.01). The effect was greater in ram than in ewe lambs (P < 0.03). Monensin treatment started when lambs were only a few weeks old and resulted in a more rapid GH response than when older lambs were treated. In some, but not all, of the experiments the lower plasma GH concentrations occurred in conjunction with an increase in ADG and an apparent increase in G:F. Monensin had little effect on plasma insulin concentrations. Key words: Lambs, monensin, growth hormone, insulin

Acute effect of growth hormone to induce peripheral insulin resistance is independent of FFA and insulin levels in rats

1999 ◽  
Vol 277 (4) ◽  
pp. E742-E749 ◽  
Author(s):  
Jason K. Kim ◽  
Cheol S. Choi ◽  
Jang H. Youn
Keyword(s):  
Insulin Resistance ◽  
Growth Hormone ◽  
Glucose Uptake ◽  
Plasma Insulin ◽  
Glycogen Synthesis ◽  
Plasma Free Fatty Acid ◽  
Acute Effect ◽  
Insulin Levels ◽  
Peripheral Insulin Resistance ◽  
Plasma Ffa

To examine whether growth hormone (GH) induces peripheral insulin resistance by altering plasma free fatty acid (FFA) or insulin levels, the effects of GH infusion on insulin-stimulated glucose fluxes were studied in conscious rats under two protocols. In study 1, either saline ( n = 7) or human recombinant GH (21 μg ⋅ kg−1 ⋅ h−1; n = 8) was infused for 300 min, and insulin-stimulated glucose fluxes were estimated during the final 150-min period of hyperinsulinemic euglycemic clamps. In study 2, hyperinsulinemic euglycemic clamps were first conducted for 150 min (to raise plasma insulin and suppress FFA levels), and saline or GH ( n = 7 for each) was subsequently infused for the following 300-min clamp period. In study 1, GH infusion in the basal state did not significantly alter plasma FFA or insulin levels. In contrast, GH infusion decreased insulin-stimulated glucose uptake, glycolysis, and glycogen synthesis by 32, 27, and 40%, respectively ( P < 0.05). In study 2, GH infusion during hyperinsulinemic euglycemic clamps did not alter plasma FFA or insulin levels ( P > 0.05). GH infusion had no effect on insulin-stimulated glucose uptake during the initial 150 min but eventually decreased insulin-stimulated glucose uptake by 37% ( P < 0.05), similar to the results in study 1. These data indicate that GH induces peripheral insulin resistance independent of plasma FFA and insulin levels. The induction of insulin resistance was preceded by suppression of glycogen synthesis, consistent with the hypothesis that metabolic impairment precedes and causes development of peripheral insulin resistance.

Studies on the carbohydrate metabolism of sheep. XIX. The metabolism of glucose, free fatty acids, and ketones after feeding and during fasting or undernourishment of non-pregnant, pregnant, and lactating ewes

1962 ◽  
Vol 13 (6) ◽  
pp. 1124 ◽  
Author(s):  
RL Reid ◽  
NT Hinks
Keyword(s):  
Blood Glucose ◽  
Blood Glucose Level ◽  
Glucose Level ◽  
Inverse Correlation ◽  
Plasma Free Fatty Acid ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Pregnant Sheep ◽  
Plasma Ffa ◽  
Pregnant Ewe

Average plasma free fatty acid (FFA) values in non-pregnant sheep in widely differing body condition, but fed at levels of maintenance or above, varied from 0.24 to 0.39 m-equiv.11. Values declined after feeding, while blood ketone levels increased. Plasma FFA value is a sensitive indicator of undernourishment in sheep; a pronounced and immediate increase followed a 40% reduction in ration. FFA and ketone levels increased during 7 days of fasting, the former markedly and to a degree depending on blood glucose level; there was a close inverse correlation between plasma FFA and blood glucose levels. Similar correlations were recorded in undernourished pregnant and lactating ewes, although FFA values were consistently higher in lactation at all blood glucose levels. Ketone levels were linearly related to FFA levels when blood glucose values exceeded 25–30 mg %. Below this level of glucose there was no further increase in FFA, but ketones increased markedly. Caloric homeostasis is relatively easily maintained in undernourished nonpregnant and lactating sheep. The undernourished pregnant ewe is susceptible to hypoglycaemia, and it is suggested that there is a critical blood glucose level of 25–30 mg % below which caloric homeostasis becomes more difficult to maintain, because of endocrine changes which markedly affect the normal pattern of fat metabolism.

OVINE PLACENTAL LACTOGEN: ACUTE EFFECTS ON INTERMEDIARY METABOLISM IN PREGNANT AND NON-PREGNANT SHEEP

1976 ◽  
Vol 69 (1) ◽  
pp. 133-137 ◽  
Author(s):  
STUART HANDWERGER ◽  
R. E. FELLOWS ◽  
M. C. CRENSHAW ◽  
THOMAS HURLEY ◽  
JANET BARRETT ◽  
...  
Keyword(s):  
Plasma Insulin ◽  
Amino Nitrogen ◽  
Plasma Free Fatty Acid ◽  
Intermediary Metabolism ◽  
Placental Lactogen ◽  
Human Placental Lactogen ◽  
Acute Effects ◽  
Pregnant Sheep ◽  
Baseline Concentrations ◽  
Nitrogen Concentrations

SUMMARY The intravenous administration of ovine placental lactogen to pregnant and non-pregnant sheep produced significant acute decreases in plasma free fatty acid, glucose and amino nitrogen concentrations. Plasma insulin concentrations decreased 1 h after administration of ovine placental lactogen and then increased significantly above baseline concentrations. The results suggest that, like human placental lactogen, ovine placental lactogen is important in the modulation of intermediary metabolism during pregnancy. The sheep is an excellent animal model for the investigation of the physiology of placental lactogen.

The measurement and effect of growth hormone in the presence of growth hormone-binding antibodies

1989 ◽  
Vol 121 (1) ◽  
pp. 193-199 ◽  
Author(s):  
P. J. Pringle ◽  
P. C. Hindmarsh ◽  
L. Di Silvio ◽  
J. D. Teale ◽  
A. B. Kurtz ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Plasma Insulin ◽  
Serum Insulin ◽  
Separation Procedure ◽  
Total Plasma ◽  
Fasting Serum ◽  
Factor I ◽  
Highly Sensitive ◽  
Antibody Complex ◽  
Plasma Gh

ABSTRACT We have developed methods for measuring the concentrations of free GH in plasma using a polyethylene glycol (PEG) separation procedure to remove antibody-bound GH within 1 h of collection. Total GH concentrations were obtained by acidification of the GH–antibody complex to release the GH followed by PEG precipitation of the antibody. The plasma GH assay had a within-assay coefficient of variation (C.V.) of 6·8% at 4·6 mU/l and a between-assay C.V. of 9·2% at 4·0 mU/l. The PEG-modified assay had a within-assay C.V. of 4·3% at 6·3 mU/l and a between-assay C.V. of 10·9% at 5·3 mU/l. Both assays had a sensitivity of 1·3 mU/l. There was good correlation between plasma and free GH concentrations in 24-h profiles in two tall children (r = 0·98; P < 0·001) and between total and free GH in the same profiles (r = 0·97; P < 0·001). GH antibodies were measured using a highly sensitive radioimmunoassay. In children who did not develop GH antibodies there was no difference between total, plasma and free GH concentrations. In contrast, in those who developed GH antibodies both total and plasma GH concentrations were markedly increased compared with free GH concentrations. The presence of GH antibodies did not affect the growth, plasma insulin-like growth factor-I concentrations or fasting serum insulin concentration responses to 1 year of therapy with biosynthetic human GH. Journal of Endocrinology (1989) 121, 193–199

Effects of growth hormone administration on the body composition and hormone levels of genetically fat sheep

1998 ◽  
Vol 67 (3) ◽  
pp. 549-558 ◽  
Author(s):  
S. M. Francis ◽  
N. B. Jopson ◽  
R. P. Littlejohn ◽  
S. K. Stuart ◽  
B. A. Veenvliet ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Body Composition ◽  
Subcutaneous Fat ◽  
Live Weight ◽  
The Body ◽  
Gh Treatment ◽  
Eye Muscle ◽  
Significant Difference ◽  
Total Fat ◽  
Plasma Gh

AbstractCoopworth sheep selected for low (lean) or high (fat) backfat have large differences in plasma GH profiles. Fat genotype ram lambs (5 months old) were treated with growth hormone (GH) to simulate the plasma GH profiles of lean sheep and investigate whether exogenous GH could modify carcass fatness. For 77 days, bovine GH was administered at 25 Uglkg live weight per day either as a single, daily subcutaneous bolus (fat bolus) or via portable pulsatile infusion pumps (fat pump) which delivered GH solution at 90-min intervals into a jugular catheter. Measurements of body composition were made by computed tomography (CT) and ultrasonic scanning during the trial, with linear carcass measurements and proximate analysis undertaken at the end of the experiment.Before treatments began, mean plasma GH levels were lower (P < 0·01) in fat control (0·34 ugll) than in lean lambs (1·1 μg/l). Several weeks after the start of the trial, mean plasma GH had increased in both fat bolus (1·2 μg/l) and fat pump (0·45 μg/l) treatment lambs with major changes in the pulsatility relative to the fat control lambs. Although these changes were maintained in the fat bolus lambs, by the end of the trial there was no significant difference in mean plasma GH between fat pump and fat control sheep. Throughout the trial, plasma 1GF-1 levels were higher in fat bolus, fat pump and lean lambs than in fat control lambs. Analysis of body composition data over the GH treatment period revealed that the slope of the allometric equation for total fat relative to empty body weight was lower in the fat bolus lambs (1·07) than in the lean lambs (1·50) with fat control and fat pump treatment lambs intermediate (1·30 and 1·36, respectively). Subcutaneous fat was later maturing in lean lambs than in fat control and bolus treatment lambs when regressed against total fat, with the fat pump treatment lambs being intermediate. Linear carcass measurements revealed changes due to GH administration in the distribution of subcutaneous fat and eye muscle dimensions.It is concluded that sheep from the fat genotype show physiological responses to exogenous GH. Increasing plasma GH levels of fat sheep increased plasma IGF-1 and had variable effects on carcass fatness. The change in body composition may be affected by the mode of administration of exogenous GH.

GLUCOSE METABOLISM, PLASMA INSULIN, AND GROWTH HORMONE SECRETION IN NEWBORN INFANTS WITH ERYTHROBLASTOSIS FETALIS COMPARED WITH NORMAL NEWBORNS AND THOSE BORN TO DIABETIC MOTHERS

PEDIATRICS ◽  
1972 ◽  
Vol 49 (5) ◽  
pp. 682-693
Author(s):  
Adriano Falorni ◽  
Francesco Fracassini ◽  
Ferdinando Massi-Benedetti ◽  
Augusto Amici
Keyword(s):  
Growth Hormone ◽  
Blood Glucose ◽  
Glucose Tolerance ◽  
Plasma Insulin ◽  
Fasting Blood Glucose ◽  
Intravenous Glucose ◽  
Fasting Plasma ◽  
Significant Difference ◽  
Fasting Plasma Insulin ◽  
Diabetic Mothers

Twenty-two erythroblastotic infants (IEF), 22 normal infants, and 12 infants of diabetic mothers (IDM) were studied during their first day of life. Blood glucose, plasma insulin, and growth hormone were measured in the first 90 minutes after I-V glucose injection (1 gm/kg). Mean fasting blood glucose of normal infants was significantly higher than that of IDMs. In four IEF, blood glucose levels lower than 20 mg/100 ml were observed. No significant difference of glucose tolerance (Kt) was found among the three groups of babies. The mean fasting plasma insulin level in IDMs was significantly higher than in control infants and in IEF. In the IEF a significant correlation was found (A) between hemoglobin (Hb) and Kt values, (B) between Hb and fasting plasma insulin. (C) between fasting blood glucose and fasting plasma insulin, and (D) between Kt and the sum of plasma insulin levels 3, 5, and 10 minutes after I-V glucose. All normal babies and sixteen IEF showed a double course of insulin response. IDM showed a nearly monophasic pattern, but with a secondary minor peak between 30 and 60 minutes in some. In six (four with hypoglycemia) of the IEF group a single peak response of plasma insulin was found, together with mean Kt and fasting plasma insulin values higher than those of control infants. Fasting mean HGH concentration in plasma showed no significant difference among the groups of infants. During intravenous glucose tolerance tests mean values in IDM significantly higher than in normal infants and in IEF were found at 90 minutes.

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