INFLUENCE OF AGE, WEIGHT AND GROWTH RATE ON BASAL LH, GROWTH HORMONE AND CORTISOL, AND ESTROGEN-INDUCED LH RELEASE IN PREPUBERTAL GILTS

1987 ◽  
Vol 67 (4) ◽  
pp. 1001-1010 ◽  
Author(s):  
R. N. KIRKWOOD ◽  
F. D. EVANS ◽  
F. X. AHERNE
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Treatment Effects ◽  
Plasma Concentrations ◽  
Pulse Amplitude ◽  
Estradiol Benzoate ◽  
Early Morning ◽  
Blood Samples ◽  
Lh Release

Thirty-six Yorkshire × Landrace gilts were selected at 74 d of age and 32 kg body weight and assigned equally to one of six treatments. The first three treatments involved feeding gilts to achieve weights of 90 kg at 175 d, 90 kg at 195 d, or 70 kg at 175 d (treatments 1, 2 and 3, respectively). A further three groups of gilts were fed to achieve the same weights (90, 90 or 70 kg) 20 d younger than those above. Upon the achievement of their final weight the latter three groups of gilts were subjected to a feed restriction in order to achieve a zero net weight for 20 d until they achieved the required age (treatments 4, 5 and 6). At the achievement of the specified age-weight end point blood samples were taken from all gilts at 2-h intervals for 24 h (2400–2200 h) for the determination of plasma concentrations of luteinizing hormone (LH), growth hormone (GH) and Cortisol. Additionally, during a 4-h period on the same day (0800–1200 h) all gilts were sampled at 15-min intervals for determination of pulsatile LH secretion. Following the initial 24-h sampling, all gilts received an intramuscular injection of estradiol benzoate (EB; 15 μg kg−1 body weight) and blood samples were collected at 6-h intervals for 72 h for determination of plasma LH. No treatment effects were noted on the mean daily plasma levels of cortisol, LH or GH. Plasma concentrations of cortisol tended to decrease with increasing age or weight, but these differences were not significant. Significant elevations of plasma GH occurred in the early morning and evening, but rarely between 0400 and 1600 h. A similar nycterohemeral rhythm was noted for plasma LH levels. There were no treatment effects on LH pulse frequency but LH pulse amplitude was greater at a given age (P < 0.07), in the heavier gilts (treatments 1 and 4 vs. 3 and 6). There was no effect of treatment on the LH response to EB injection, although two patterns of LH release were observed, involving either a single or a double peak of LH. Key words: Gilts, age, weight, puberty

Endocrine changes and their relationship with body weight in growing yaks

2002 ◽  
Vol 74 (1) ◽  
pp. 89-94
Author(s):  
Tian Yongqiang ◽  
Zhao Xingxu ◽  
Wang Minqiang ◽  
Lu Zhonglin ◽  
Zhang Rongchang
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Seasonal Change ◽  
Seasonal Changes ◽  
Significant Positive Correlation ◽  
The Body ◽  
Nutrition Status ◽  
Blood Samples ◽  
Different Seasons ◽  
Grass Growth

AbstractThe concentrations of growth hormone (GH), insulin (Ins), tri-iodothyronine (T3) and thyroxine (T4) in blood samples of growing yaks during different bimonthly seasons were determined by radioimmunoassay. The changes of body weight of growing yaks and composition of grass grazed were measured accordingly. The seasonal changes of hormones were significant (P < 0·01 or P < 0·05). Within season, the variances of hormones depended upon the different growing stages. The body-weight gains in the different groups varied in different seasons, increase being significant in May, July and September, decrease being significant from January to May. Correlation analysis indicated that T4 concentration had a significant positive correlation with the body weight of the growing yaks(r = 0·2509, P < 0·05) and other hormones did not have any significant correlation with body weight. The results showed that the annual cycle of weight loss and gain was attributed to the seasonal change of nutrition status. The seasonal change of the assayed hormones depended on the grass growth.

Use of Values for Calcium and Protein Serum, and of a Derived Index Obtained from a Probability Population Sample

1978 ◽  
Vol 24 (3) ◽  
pp. 506-506
Author(s):  
Anthea Kelly ◽  
Louis Munan ◽  
Claude PetitClerc ◽  
Kok Ping Ho ◽  
Bernard Billon
Keyword(s):  
Body Weight ◽  
Ursodeoxycholic Acid ◽  
Blood Sample ◽  
Cholic Acid ◽  
Amylase Activity ◽  
Population Sample ◽  
Blood Samples ◽  
Annual Index ◽  
Protein Serum

Abstract Volume 22 p 1726: In the footnote to Table 3, the last half of the sentence should read " for SI units, the index becomes (80 calcium - 120)/protein." Volume 23 p 1779: In column two of "corrections," the word "malate" should be substituted for "maleate." p 2127: In column two, last line, change "chinic" to "chenodeoxycholic." On the next page, change the last part of the sub-legend to Figure 7 to read "(5) ursodeoxycholic acid, (6) cholic acid." p 2205: col. two, line 32. For "mg/g body weight" read "mg/kg body weight." p 2288: In the last sentence of the abstract, change ".... 0.3 to 7.8 mole..." to "... 0.3 to 7.8 mmol...." p 2289: Table 1, footnote a should read: "Millimoles of 4NP injected/270 x 10-3 moles of 4NPP. This is calculated as if the 4NP were present in 270 nmol of 4NPP...." p 2290: In Table 2, in column A "7.76d" should read "7.76c" p 2356: The reader may incorrectly infer that the "Gamma-Coat Kit" (CA 535, 536; 555, 556) is intended for the analysis of dried blood samples on paper in screening for congenital hypothyroidism in infants. Actually, that kit is intended for serum thyroxine assay. A modified kit dedicated to dried blood-sample screening for hypothyroidism is currently under development and will be introduced shortly as CA-538, 558. Further, in Tables and text, the "3.5-mm" disks referred to should read "3.18 mm" (⅛''). This is of significance, because the error in diameter produces a 20% error in the apparent blood volume or thyroxine content per disk in the Tables. Inadvertent omissions from the list of invited reviewers (p 2360) and our annual index are, respectively: Jocelyn M. Hicks and Royden Rand and "Direct Spectrophotometric Determination of α-Amylase Activity in Saliva, with p-Nitrophenyl α-Maltoside as Substrate," by Baiba K. Gillard, Henry C. Markman, and Stephen A. Feig. (p 2279)

Generation of growth hormone pulsatility in women: evidence against somatostatin withdrawal as pulse initiator

2001 ◽  
Vol 280 (3) ◽  
pp. E489-E495 ◽  
Author(s):  
Eleni V. Dimaraki ◽  
Craig A. Jaffe ◽  
Roberta Demott-Friberg ◽  
Mary Russell-Aulet ◽  
Cyril Y. Bowers ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Growth Hormone ◽  
Postmenopausal Women ◽  
Normal Saline ◽  
Driving Force ◽  
Pulse Amplitude ◽  
Pulse Frequency ◽  
Blood Samples ◽  
Stable Plasma ◽  
Plasma Gh

To test whether endogenous hypothalamic somatostatin (SRIH) fluctuations are playing a role in the generation of growth hormone (GH) pulses, continuous subcutaneous octreotide infusion (16 μg/h) was used to create constant supraphysiological somatostatinergic tone. Six healthy postmenopausal women (age 67 ± 3 yr, body mass index 24.7 ± 1.2 kg/m2) were studied during normal saline and octreotide infusion providing stable plasma octreotide levels of 2,567 ± 37 pg/ml. Blood samples were obtained every 10 min for 24 h, and plasma GH was measured with a sensitive chemiluminometric assay. Octreotide infusion suppressed 24-h mean GH by 84 ± 3% ( P = 0.00026), GH pulse amplitude by 90 ± 3% ( P = 0.00031), and trough GH by 54 ± 5% ( P = 0.0012), whereas GH pulse frequency remained unchanged. The response of GH to GH-releasing hormone (GHRH) was not suppressed, and the GH response to GH-releasing peptide-6 (GHRP-6) was unaffected. We conclude that, in women, periodic declines in hypothalamic SRIH secretion are not the driving force of endogenous GH pulses, which are most likely due to episodic release of GHRH and/or the endogenous GHRP-like ligand.

Determination of rate of cross circulation in parabiotic rats with P32-labeled erythrocytes

1959 ◽  
Vol 196 (4) ◽  
pp. 753-756 ◽  
Author(s):  
David G. Fleming ◽  
Laura Caldwell ◽  
Roberta Jacobs
Keyword(s):  
Body Weight ◽  
Blood Volume ◽  
Sodium Phosphate ◽  
Femoral Vein ◽  
Total Activity ◽  
Female Rats ◽  
Blood Samples ◽  
Litter Mate ◽  
Blood Volumes

Litter-mate female rats parabiosed at 21 days by the Bunster-Meyer method were allowed to mature for several months. Volumes of blood obtained from donor animals were incubated at 37°C with P32, in the form of buffered isotonic sodium phosphate. A plasma-free suspension of labeled erythrocytes was prepared and a sample of known activity was injected into the femoral vein of one member of each parabiotic pair. Four pairs of 100 lambda blood samples, obtained by venipuncture, were taken at varying intervals, for the succeeding 150 minutes. Using the dye dilution principle, it was possible to determine the blood volume of the injected rat after the first sample, and that of the pair at the time of equilibrium. The average blood volume was 6.53% of body weight. The concentration of tagged cells reached equal values in both members of the pairs at an average time of 90 minutes. There was less than a 20% loss of total activity in all the pairs used for determinations. An equation was derived for the calculation of the rate of exchange. The average for 15 pairs was 2.09 blood volumes per hour. The range was from 3.95 bl. vol/hr. in the fastest pair to 0.74 bl. vol/hr. in the slowest.

Serum somatotropin concentrations in Holstein heifers administered growth hormone-releasing factor and somatostatin

1998 ◽  
Vol 66 (3) ◽  
pp. 551-556 ◽  
Author(s):  
G. W. Kazmer ◽  
S. A. Zinn
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Early Identification ◽  
Response Curve ◽  
Dairy Calves ◽  
Production Traits ◽  
Individual Animal ◽  
Milk Production Traits ◽  
Serum Growth Hormone ◽  
Blood Samples

AbstractDose-response experiments were designed to determine the dosage of somatostatin (SRIF) necessary to alter serum growth hormone (GH) response to administration of GH-releasing factor (1·44; GRF) in cattle. The objective of this experimentation was to develop a GRF/SRIF challenge model that might be useful in early identification of animals which are genetically superior for milk production traits. In experiment 1, calves received either 0, 5 or 10 /JLg GRF per 100 kg body weight (BW) or GRF 1·29 at 1 ug per 100 kg BW. Both the 5 and 10 ug GRF per 100 kg BW dosages increased GH concentrations (P < 0·05). In experiment 2, animals received 3 ug GRF per 100 kg BW concurrent with administration of 0, 0·5, 1 or 2 ug SRIF per 100 kg BW at 0 min, with second dosage of GRF at +120 min. Administration of SRIF in those dosages did not alter GH response to GRF. In experiment 3, animals received 5 ug SRIF per 100 kg BW at -2, -1, 0 or +1 min relative to 3 ug GRF per 100 kg BW, with a second GRF injection at +120 min. No differences (P < 0·05) were found in response due to timing of SRIF administration. In experiment 4, animals were administered 0, 5, 10 or 20 Xg SRIF per 100 kg BW concurrent with 3 ug GRF per 100 kg BW. SRIF delayed (P < 0·05) the occurrence of maximum GH concentrations but did not affect the maximum concentration nor the area under the GH response curve (AUC) following either the first or second GRF injection. Utilizing data from experiment 4, individual animal response to GRF was reasonably consistent, as repeatabilities of AUCs for 1 h following first and second GRF injections were 0·80 and 0·65, respectively. Furthermore, sufficient among-animal variation existed so that animals could be distinguished from each other. Thus we conclude the method described herein might be useful in identifying superior dairy calves but accuracy would potentially be enhanced by collecting blood samples more frequently during the 20 min immediately after GRF injection.

Growth hormone response to growth hormone-releasing hormone in normal and uraemic children. Comparison with hypoglycaemia following insulin administration

1987 ◽  
Vol 114 (1) ◽  
pp. 5-11 ◽  
Author(s):  
D. Bessarione ◽  
F. Perfumo ◽  
M. Giusti ◽  
F. Ginevri ◽  
G. Mazzocchi ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Adverse Effects ◽  
Significant Variation ◽  
Growth Hormone Releasing Hormone ◽  
Blood Samples ◽  
Releasing Hormone ◽  
Uraemic Children ◽  
Insulin Test ◽  
Peak Value

Abstract. The uraemic syndrome is characterized by several endocrinological disturbances. This study was undertaken in order to evaluate the GH response to growth hormone-releasing hormone (GRH) in children with chronic renal failure (CRF) and to compare the results with those observed after insulin hypoglycaemia. Twenty-two children with CRF, 10 undergoing continuous ambulatory peritoneal dialysis (CAPD) and 12 on conservative treatment (CT), age ranges 2–15 years, were studied and the data were compared with those from 14 children with normal renal function and normal hormonal behaviour, affected by short stature (NC), and those form 13 healthy adult volunteers (NA). The GRH test (1 μg/kg body weight, iv) was carried out in 8 CAPD, 8 CT, 9 NC and 10 NA subjects. The blood samples were taken every 30 min for 3 h in CAPD and CT and for 2 h in NC and NA starting at 09.00 h. The following hormones were measured: GH, LH, FSH, Prl, TSH and cortisol (F). The insulin test (0.1 U/kg body weight, iv) was carried out in 5 CAPD, 5 CT, 10 NC and 9 NA on blood samples taken every 30 min for 2 h, measuring GH and glycaemia. No adverse effects were observed after the infusion of GRH. GRH administration induced a prompt response in all subjects, but GH plasma levels were significantly higher in uraemic children than in adults (peak value of 43.5 ± 8.2, 45.0 ± 8.4, 27.8 ± 6.0; 13.5 ± 2.6 μg/ml in CAPD, CT, NC and NA, respectively). The secretory areas were significantly narrower in NC (P < 0.05) and NA (P < 0.01) than in CAPD, and in NA than in CT (P < 0.01). The GH response to insulin did not differ in the 4 groups. The secretory area in CAPD and CT was wider after GRH than after insulin. The GH peak value of CAPD and NC was significantly higher after GRH than following insulin. No significant variation in TSH, LH and FSH was observed after the infusion of the neuropeptide, whereas Prl and F showed a reduction. The behaviour of Prl and F in NA and NC was similar after placebo and GRH. Our data show: a) There is a greater response of GH to GRH in children than in adults; b) compared with the insulin test, GRH stimulation seems to be a reliable means of evaluating GH secretion both in normal and uraemic children owing to the absence of qualitatively different responses and to the freedom from the adverse effects or risks which follow insulin infusion; c) GRH administration does not induce any significant variation on other hypophyseal hormones and the reduction of Prl and F seems to follow the normal sleep-wake and circadian behaviour.

THE INFLUENCE OF GROWTH HORMONE TREATMENT ON THYROID FUNCTION IN SWINE

1990 ◽  
Vol 70 (3) ◽  
pp. 991-995 ◽  
Author(s):  
R. N. KIRKWOOD ◽  
P. A. THACKER ◽  
B. LAARVELD
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Key Words ◽  
Growth Hormone Treatment ◽  
Sampling Period ◽  
Hormone Treatment ◽  
Serum Concentrations ◽  
Significant Treatment ◽  
Blood Samples ◽  
To Receive

Twelve castrated male pigs of Yorkshire and Landrace breeding were selected at 95.9 ± 1.6 kg body weight (BW) and allocated equally to receive daily injections of either porcine growth hormone (pGH) at 90 μg kg−1 BW or vehicle buffer for four consecutive days. Following the last pGH injection, the pigs were infused via indwelling vena caval cannulae with thyrotropin-releasing hormone (TRH) at 0.5 μg kg−1 BW. Blood samples were obtained at 10 and 0 min before TRH and thereafter at 10-min intervals for 90 min. Serum concentrations of thyroxine and thyrotropin were lower (P < 0.06 and P < 0.1, respectively) but those of triiodothyronine higher (P < 0.01) in pGH-treated pigs throughout the sampling period. There were no significant treatment-by-time interactions indicating that the thyroid response to TRH was not influenced by pGH treatment. Key words: Swine, thyroid, growth hormone, somatotropin

THE INFLUENCE OF GILT AGE ON THE ENDOCRINE AND OVULATORY RESPONSE TO DIFFERENT DOSES OF ESTRADIOL BENZOATE

1988 ◽  
Vol 68 (3) ◽  
pp. 979-982 ◽  
Author(s):  
R. N. KIRKWOOD ◽  
F. X. AHERNE
Keyword(s):  
Body Weight ◽  
Luteinizing Hormone ◽  
Key Words ◽  
Jugular Vein ◽  
Estradiol Benzoate ◽  
Blood Samples ◽  
Estrous Cyclicity ◽  
The Mean ◽  
Different Doses ◽  
Phasic Release

Fifty-five prepubertal Yorkshire × Landrace gilts were randomly assigned to one of six treatments involving the injection (i.m.) of estradiol benzoate (EB) at either 10 or 20 μg kg−1 body weight at gilt ages of 130, 150 or 170 d. Blood samples were taken by jugular vein puncture at 0, 24, and 36 h, and then at 6-h intervals until 84 h, after injection and assayed for plasma luteinizing hormone (LH) concentrations. The mean magnitude of the EB-induced LH peak was 6.1 ± 0.2 ng mL−1, and was not affected by treatment. Fifty-six percent of gilts ovulated in response to EB injection, and 34% had a subsequent ovulation. The initial ovulation rate was unaffected by EB dose, but was higher (P < 0.05) in 170 d (9.9 ± 1.0) compared to younger gilts (4.2 ± 1.1 and 5.5 ± 1.1 for 130-dand 150-d gilts, respectively). Subsequent ovulation rates were unaffected by treatment. It is concluded that EB treatment will usually induce a phasic release of LH from prepubertal gilts, but this release is not necessarily accompanied by normal estrous cyclicity. Key words: Estradiol, gilts, ovulation

A note on the variability of hormone concentrations in twice-weekly blood samples taken from heifer calves during the first 110 days of life

1981 ◽  
Vol 32 (2) ◽  
pp. 215-217 ◽  
Author(s):  
I. C. Hart ◽  
S. V. Morant ◽  
J. H. B. Roy
Keyword(s):  
Growth Hormone ◽  
Plasma Concentrations ◽  
Early Age ◽  
Production Potential ◽  
Blood Samples ◽  
Plasma Hormone

ABSTRACTTo assess the variability of hormone values obtained from calves at an early age, plasma concentrations of prolactin, growth hormone, insulin and thyroxine were measured in blood samples taken twice-weekly from seven heifers maintained under commercial conditions during their first 110 days of life. With the possible exception of thyroxine, there was considerable variation in the concentration of each hormone in each animal throughout the period of sampling, thus indicating that twice-weekly sampling was inadequate for investigating differences in hormonal concentrations between cattle of different production potential. Although there were trends in the pattern of plasma hormone concentrations as the calves progressed from the pre-ruminant to ruminant states, few of the changes during the pre-weaning, weaning and post-weaning periods were consistent between animals.

Pulsatile and nocturnal growth hormone secretions in men do not require periodic declines of somatostatin

2003 ◽  
Vol 285 (1) ◽  
pp. E163-E170 ◽  
Author(s):  
Eleni V. Dimaraki ◽  
Craig A. Jaffe ◽  
Cyril Y. Bowers ◽  
Peter Marbach ◽  
Ariel L. Barkan
Keyword(s):  
Growth Hormone ◽  
Diurnal Rhythm ◽  
Pulse Amplitude ◽  
Pulse Frequency ◽  
Pulse Generation ◽  
Sexually Dimorphic ◽  
Blood Samples ◽  
Gh Secretion ◽  
Stable Plasma ◽  
Hormone Secretions

Using a continuous subcutaneous octreotide infusion to create constant supraphysiological somatostatinergic tone, we have previously shown that growth hormone (GH) pulse generation in women is independent of endogenous somatostatin (SRIH) declines. Generalization of these results to men is problematic, because GH regulation is sexually dimorphic. We have therefore studied nine healthy young men (age 26 ± 6 yr, body mass index 23.3 ± 1.2 kg/m2) during normal saline and octreotide infusion (8.4 μg/h) that provided stable plasma octreotide levels (764.5 ± 11.6 pg/ml). GH was measured in blood samples obtained every 10 min for 24 h. Octreotide suppressed 24-h mean GH by 52 ± 13% ( P = 0.016), GH pulse amplitude by 47 ± 12% ( P = 0.012), and trough GH by 39 ± 12% ( P = 0.030), whereas GH pulse frequency and the diurnal rhythm of GH secretion remained essentially unchanged. The response of GH to GH-releasing hormone (GHRH) was suppressed by 38 ± 15% ( P = 0.012), but the GH response to GH-releasing peptide-2 was unaffected. We conclude that, in men as in women, declines in hypothalamic SRIH secretion are not required for pulse generation and are not the cause of the nocturnal augmentation of GH secretion. We propose that GH pulses are driven primarily by GHRH, whereas ghrelin might be responsible for the diurnal rhythm of GH.

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