Somatotrophic and thyroid hormones around the onset of lay in broiler breeders under different conditions

2002 ◽  
Vol 50 (4) ◽  
pp. 425-434
Author(s):  
R. D. Malheiros ◽  
Vera Maria Barbosa Moraes ◽  
R. L. Furlan ◽  
Keyword(s):  
Thyroid Hormones ◽  
Cell Function ◽  
High Plasma ◽  
Significant Rise ◽  
Broiler Breeders ◽  
Housing Systems ◽  
Gh Secretion ◽  
Age Related ◽  
Group A ◽  
Plasma Gh

Somatotrophic and thyroid hormones were determined around the onset of reproduction in broiler breeders reared in two different housing systems [dark, close-sided house (CH) and conventional, open-sided house (OH)]. In both groups age-related changes were obvious for thyroxine (T4), growth hormone (GH) and insulin-like growth factor (IGF-1); levels of T4 decreased, especially between 24 and 28 weeks in both groups; concomitantly GH sharply increased over the same period. A transient peak in triiodothyronine (T3) occurred between 25 and 27 weeks. The effect of housing was only present after the onset of lay. Between weeks 27-28 and the end of the period studied, the CH group showed higher levels of GH and T3 but lower T4 levels as compared to the OH group. A significant increase in GH after onset of lay, without any significant rise in T3 or in IGF-I, could point to a relative insensitivity to high plasma GH levels. Changes at GH receptor level, together with an increased pituitary GH secretion and/or decreased GH turnover may be expected. This may indicate that hypothalamo-pituitary changes at the onset of lay not only imply changes of gonadotrophic cell function, but also other hormonal axes. The relatively decrease in T4 without changes in T3, may point to a decrease in the activity of the thyrotropic axis.

Prolonged fasting or clonidine can restore the defective growth hormone secretion in old dogs

1989 ◽  
Vol 121 (2) ◽  
pp. 177-184 ◽  
Author(s):  
Silvano G. Cella ◽  
Valerio Moiraghi ◽  
Francesco Minuto ◽  
Antonina Barreca ◽  
Daniela Cocchi ◽  
...  
Keyword(s):  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Peak Frequency ◽  
Prolonged Fasting ◽  
Total Peak Area ◽  
Gh Secretion ◽  
Age Related ◽  
Adrenoceptor Agonist ◽  
Baseline Conditions ◽  
Plasma Gh

Abstract. Age-related changes in GH secretion were studied in the dog. In preliminary experiments, administration of GH-relasing hormone (GHRH-40, 2 μg/kg, iv) or the α2-adrenoceptor agonist clonidine (4 μg/kg, iv) elicited significantly higher plasma GH rises in 3 to 4 years old than in 10 to 14 years old beagle dogs. The pulsatile patterns of GH secretion in both young and old dogs under baseline conditions and after prolonged fasting or clonidine administration were studied. Samples were taken every 10 min from 09.00 to 15.00 h from five young and five old dogs of both sexes. Under baseline conditions, GH peak frequency, total peak area, and integrated GH secretion were significantly lower in old than in young dogs. In old dogs, 5-day complete fasting or 14-day clonidine administration (75 μg/dog, po, twice daily) increased the frequency and amplitude of spontaneous GH bursts, the total peak area, and the integrated GH secretion. After either stimulus, the GH secretory pattern was quantitatively and qualitatively indistinguishable from that of young dogs under baseline conditions. Similarly, the foregoing indices were significantly increased in young dogs by either stimulus, except for the inability of clonidine to affect peak frequency. These data demonstrate that the defective GH secretion in old dogs is not irreversible, since it is normalized when old dogs are exposed to central nervous system-directed stimuli.

ROLE OF SEROTONIN IN THE REGULATION OF GROWTH HORMONE AND PROLACTIN SECRETION IN THE DOMESTIC FOWL

1981 ◽  
Vol 90 (3) ◽  
pp. 355-358 ◽  
Author(s):  
JAMSHID RABII ◽  
F. BUONOMO ◽  
C. G. SCANES
Keyword(s):  
Domestic Fowl ◽  
Serotonin Receptor ◽  
Young Male ◽  
Prolactin Secretion ◽  
Significant Rise ◽  
Plasma Prolactin ◽  
Significant Drop ◽  
Gh Secretion ◽  
Serotonin Receptor Antagonists ◽  
Plasma Gh

Plasma levels of GH and prolactin were measured by radioimmunoassay in male domestic fowl treated with centrally active agents. p-Chlorophenylalanine (pCPA) did not have an effect on tonic levels of prolactin but led to a significant rise in circulating GH concentrations. The three serotonin receptor antagonists tested, methysergide, SQ-10631 and cyproheptadine, each resulted in a significant reduction in plasma prolactin while markedly increasing plasma GH levels. Administration of 5-hydroxytryptophan led to a rise in plasma prolactin and a drop in plasma GH levels in untreated birds or in animals pretreated with pCPA. The serotonin receptor agonist, quipazine, resulted in a marked increase in plasma prolactin and a marked reduction in plasma GH concentrations in untreated birds. In pCPA-pretreated animals quipazine was no longer effective in altering plasma prolactin levels but still caused a significant drop in circulating levels of GH. These results suggest that in the young male domestic fowl serotonin has a stimulatory role in the regulation of prolactin and an inhibitory role in the regulation of GH secretion.

Acromegaly due to ectopic growth hormone-releasing hormone secretion by a bronchial carcinoid tumour. Dynamic hormonal responses to various stimuli

1991 ◽  
Vol 125 (4) ◽  
pp. 366-371 ◽  
Author(s):  
Michael Glikson ◽  
Irit Gil-Ad ◽  
Eithan Galun ◽  
Rivka Dresner ◽  
Shalom Zilberman ◽  
...  
Keyword(s):  
Pituitary Adenoma ◽  
Carcinoid Tumour ◽  
Hormone Secretion ◽  
High Plasma ◽  
Somatostatin Analogue ◽  
Bronchial Carcinoid ◽  
Mixed Meal ◽  
Gh Secretion ◽  
Before And After ◽  
Plasma Gh

Abstract. Ectopic GHRH is a relatively uncommon cause of acromegaly, which should be differentiated from pituitary adenoma, in order to avoid damage to the pituitary gland from unnecessary interventions. We report here on a 66-year-old man with acromegaly due to a GHRH-secreting bronchial carcinoid tumour, who recovered completely following removal of the tumour. His hormonal status was studied before and after the operation. Basal GH, GHRH, IGF-I and PRL levels, as well as plasma GH response to glucose load and TRH administration were abnormal before the operation, and became normal thereafter. The somatostatin analogue SMS 201-995 was found to be a potent inhibitor of the ectopic GHRH and the GH secretion (>500 to 42 ng/l and 15.4 μg/l to 0.8 μg/l, respectively). The effect on GHRH proved to be due to direct effect of somatostatin on the tumour cells, as demonstrated in tissue culture studies. A mixed meal was found immediately to suppress GHRH levels without such an effect on GH secretion. We conclude that the neuroendocrine tests usually practised in acromegaly cannot differentiate between ectopic GHRH secretion and pituitary adenoma. High plasma GHRH levels may serve as a diagnostic test for excessive GHRH production, which is almost always ectopic. These high levels are suppressible by somatostatin and a mixed meal.

Lack of growth hormone response to acute administration of dexamethasone in anorexia nervosa

1995 ◽  
Vol 132 (2) ◽  
pp. 152-158 ◽  
Author(s):  
Massimo Scacchi ◽  
Cecilia Invitti ◽  
Angela I Pincelli ◽  
Claudio Pandolfi ◽  
Antonella Dubini ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Anorexia Nervosa ◽  
Normal Subjects ◽  
High Plasma ◽  
Normal Weight ◽  
Growth Hormone Response ◽  
Acute Administration ◽  
Hormone Response ◽  
Gh Secretion ◽  
Plasma Gh

Scacchi M, Invitti C, Pincelli AI, Pandolfi C, Dubini A, Cavagnini F. Lack of growth hormone response to acute administration of dexamethasone in anorexia nervosa. Eur J Endocrinol 1995;132:152–8. ISSN 0804–4643 High plasma growth hormone (GH) levels, associated with abnormal hormone responses to provocative stimuli, point to an altered GH secretion in anorexia nervosa. The GH-releasing effect of acutely administered glucocorticoids, firmly established in normal subjects, has not been reported in these patients. In this study, acute iv administration of 4 mg of dexamethasone, compared with saline, increased plasma GH in nine normal-weight women (AUC 848.2 ± 127.95 vs 242.8 ± 55.35 μg·l−1·min−1, p < 0.05, respectively) but was ineffective in 11 anorectic patients (AUC 3271.8 ± 1407.11 vs 2780.0 ± 1162.04 μg·l−1·min−1, NS). After dexamethasone, a significant lowering of plasma cortisol was observed in normal women (AUC 25367.0 ± 3128.43 vs 47347.1 ± 4456.61 nmol·l−1·min−1, after dexamethasone and saline, respectively, p < 0.05), but not in anorectic patients (AUC 77809.3 ± 8499.92 vs 78454.9 ± 7603.62 nmol·l−1·min−1, NS). In both groups, plasma adrenocorticotrophin (ACTH) displayed a significant decrease after dexamethasone (AUC 523.6 ± 92.08 vs 874.2 ± 115.03 pmol·l−1·min−1, p < 0.05, after dexamethasone and saline, respectively, in anorectic patients and 377.5 ± 38.41 vs 1004.9 ± 200.51 pmol·l−1·min−1, p < 0.05, in controls). However, when considering the hormonal decremental areas, a significant dexamethasone-induced ACTH inhibition, compared to saline, was evidenced in normal (ΔAUC –414.4 ± 65.75 vs 222.9 ± 42.40 pmol·l−1·min−1, p < 0.05) but not in anorectic women (ΔAUC –254.2 ± 96.92 vs 2.9 ± 132.32 pmol·l−1·min−1, NS). In conclusion, compared to normal subjects, anorectic patients do not display an increase of plasma GH levels and show a lower degree of inhibition of the hypothalamic–pituitary–adrenal axis following acute iv administration of dexamethasone. This observation broadens the array of the abnormal GH responses to provocative stimuli in anorexia nervosa and supports the existence, in these patients, of a decreased hypothalamic somatostatin secretion, although the possibility of a reduced tissue sensitivity to glucocorticoids cannot be excluded. Francesco Cavagnini, 2nd Chair of Endocrinology, University of Milan, Istituto Scientifico Ospedale San Luca, Centro Auxologico Italiano, via Spagnoletto 3, 20149 Milano, Italy

Plasma growth hormone profile in acromegaly before and ten days after transsphenoidal surgery

1989 ◽  
Vol 120 (1) ◽  
pp. 113-120 ◽  
Author(s):  
Staffan Edén ◽  
Bengt-Åke Bengtsson ◽  
Kerstin Albertsson-Wikland ◽  
Jörgen Elfversson ◽  
Göran Lindstedt ◽  
...  
Keyword(s):  
Transsphenoidal Surgery ◽  
High Plasma ◽  
Peripheral Vein ◽  
Plasma Growth Hormone ◽  
Somatomedin C ◽  
Gh Secretion ◽  
Hormone Profile ◽  
Plasma Gh ◽  
Serum Gh

Abstract. Profiles of plasma GH, plasma somatomedin-C and serum PRL concentrations as well as serum GH response to iv TRH were determined in 11 patients with acromegaly before and 10 days after surgery. Blood for profile determinations was drawn from a peripheral vein with a continuous withdrawal pump changing the recipient tube at 30-min intervals. Before surgery all patients had high plasma GH concentrations with irregular peaks and somatomedin-C concentrations were elevated. The response to TRH was abnormal in 8 patients. Three patients had slightly elevated PRL concentrations and one had high PRL concentration (6900 mU/l). Ten days after surgery GH concentrations were still high in 2 patients (>5 mU/l), as were somatomedin-C concentrations (3.2 and 2.4 U/l, respectively). In 3 patients basal GH concentrations were <5 mU/l and somatomedin-C concentrations were normal, but there were no major peaks in plasma GH concentrations. In 2 patients major peaks in GH concentrations appeared after surgery, but basal GH concentrations were 1.9 and 0.95 mU/l, respectively. One patient with hyperprolactinemia still had slightly elevated PRL concentration (486 mU/l), but the response to TRH was normalized. Finally, in 4 patients, mean GH concentrations were markedly reduced, somatomedin-C concentrations normalized and apparently normal plasma GH profiles appeared with low or undetectable basal levels separating major peaks. The results indicate that in some patients with acromegaly apparently normal GH secretion can be demonstrated 10 days postoperatively. Characterization of circadian GH rhythms during the early postoperative stage may contribute to the evaluation of the effect of surgery.

DIMINUTION OF THYROTROPHIN RELEASING HORMONE-INDUCED GROWTH HORMONE SECRETION IN ADULT DOMESTIC FOWL (GALLUS DOMESTICUS)

1981 ◽  
Vol 89 (3) ◽  
pp. 405-410 ◽  
Author(s):  
S. HARVEY ◽  
R. J. STERLING ◽  
J. G. PHILLIPS
Keyword(s):  
Domestic Fowl ◽  
Laying Hens ◽  
Hormone Secretion ◽  
Plasma Concentrations ◽  
Growth Hormone Secretion ◽  
Thyrotrophin Releasing Hormone ◽  
Releasing Hormone ◽  
Gh Secretion ◽  
Age Related ◽  
Plasma Gh

Age-related changes in the response of GH to administration of thyrotrophin releasing hormone (TRH) have been investigated in the domestic fowl. In two strains of chicken the i.v. administration of TRH (10 μg/kg) to 4-week-old male and female birds markedly increased (> 200 ng/ml) the plasma GH concentration within 10 min of treatment and the concentration remained higher than the pretreatment level for at least a further 20 min. Saline (0·9%) administration had no effect on GH secretion in comparable groups of control birds. The same dose of TRH had no effect on plasma GH concentrations in adult (> 24-week-old) laying hens or cockerels. The administration of TRH at doses of 0·1–100 μg/kg (i.v.) or 0·39–50 μg/bird (s.c.) also had very little, if any, effect on GH secretion in laying hens. In laying hens slight increases (10–20 ng/ml, P < 0·05) in the plasma concentrations of GH were observed in one experiment 60 min after the s.c. injection of 100 μg TRH, and in another 60, 90 and 120 min after the serial s.c. injection of TRH (100 μg/bird) every 30 min over a 150 min period. The poor GH response of the adults to TRH stimulation was not due to high circulating concentrations of endogenous gonadal steroids, as surgical gonadectomy had no effect on the GH response to TRH. These results suggest maturational differences in the control of GH secretion in the fowl.

Effects of repetitive administration of growth hormone-releasing hormone on growth hormone secretion, insulin-like growth factor I, and bone metabolism in postmenopausal women

1989 ◽  
Vol 120 (1) ◽  
pp. 121-128 ◽  
Author(s):  
Paul Franchimont ◽  
Didier Urbain-Choffray ◽  
Pierre Lambelin ◽  
Marie-Anne Fontaine ◽  
Gerard Frangin ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Bone Metabolism ◽  
Postmenopausal Women ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Significant Rise ◽  
Maximum Peak ◽  
Gh Secretion ◽  
Age Related ◽  
Igf I

Abstract. This study sought to determine whether GH response to synthetic GHRH was impaired in 13 postmenopausal (55-71 years) as compared with that in 8 eugonadal women and whether IGF-I and bone metabolism were consequently depressed. Thereafter, the effects of daily iv injections of 80 μg GHRH-44 for 8 days were studied in the same postmenopausal group. In addition to significantly higher basal IGF-I and osteocalcin levels (P< 0.005) in eugonadal as compared with the postmenopausal women, the administration of one GHRH-44 injection resulted in significantly higher 120-min postinjection GH maximum peak and cumulative responses in the former group as well (P< 0.005). Highly significant correlations were observed between 17β-estradiol plasma levels and either GH maximum peak or cumulative responses to GHRH-44 when both groups were pooled together, but not when considered independently. In postmenopausal women, a correlation was found between both age and duration of menopause and GH responses. Repeated GHRH-44 injections in postmenopausal women induced a significant increase in GH response (P< 0.001) as well as in IGF-I levels from day 4 to 8. No phospho-calcium parameters were modified except for a significant rise in osteocalcin from day 2 to 8. These data indicate an age-related loss of sensitivity of somatotrope cells to GHRH-44 in postmenopausal women, partly corrected by repeated daily GHRH-44 injections. As a consequence of the GHRH-induced increase in GH secretion, IGF-I was also enhanced and may be responsible for a stimulatory effect on bone formation, as shown by the osteocalcin increase, uncoupled from bone resorption.

The role of thyroid hormones in the growth hormone response to protein restriction in the domestic fowl (Gallus domesticus)

1988 ◽  
Vol 117 (2) ◽  
pp. 223-228 ◽  
Author(s):  
T. J. Lauterio ◽  
C. G. Scanes
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Hormones ◽  
Plasma Concentrations ◽  
Hormone Response ◽  
Gh Secretion ◽  
Low Protein ◽  
Increased Sensitivity ◽  
Plasma Gh ◽  
Protein Diets

ABSTRACT The possible role of thyroid hormones in the rise in plasma GH observed in protein-restricted chicks was examined. Increased sensitivity of protein-restricted chicks to secretagogue challenge (TRH or GH-releasing factor) appears to account, at least in part, for increased GH concentrations in protein-restricted chicks. Thyroid hormones administered acutely were able to suppress plasma GH concentrations in protein-restricted chicks. Further, chronic thyroid hormone supplementation to low protein diets normalized circulating thyroid hormone concentrations and also normalized the response to GH secretagogue challenge. This decreased sensitivity to TRH provocation occurred without an accompanying change in plasma concentrations of insulin-like growth factor-I, a reputed inhibitor of GH secretion in the chicken. J. Endocr. (1988) 117, 223–228

Age related volume of cadaver-prostates in Bangladesh

1970 ◽  
Vol 4 (2) ◽  
pp. 74-77
Author(s):  
Rukshana Ahmed ◽  
Shamim Ara
Keyword(s):  
Prostate Gland ◽  
Age Groups ◽  
Clinical Settings ◽  
Cross Sectional ◽  
Medical College ◽  
Age Related ◽  
Group A ◽  
Key Words Prostate ◽  
The Mean ◽  
Group B

Pathological changes in the prostate gland occur commonly with advancing age including inflammation, atrophy, hyperplasia and carcinoma and a change in volume is also evident. Estimation of volume of prostate may be useful in a variety of clinical settings. A cross-sectional descriptive study was designed to see the changes in volume of the prostate with advancing age and done in the Department of Anatomy, Dhaka Medical College, Dhaka from August 2006 to June 2007. The study was performed on 70 post-mortem human prostates collected from the unclaimed dead bodies that were under examination in the Department of Forensic Medicine, Dhaka Medical College, Dhaka. The samples were divided into three age groups; group A (10-20 years), group B (21-40 years) and group C (41-70 years). Volume of the sample was measured by using the ellipsoid formula. The mean ± SD volume of prostate was 7.68 ± 3.64 cm3 in group A, 10.61 ± 3.99 cm3 in group B and 15.40 ± 6.31 cm3 in group C. Mean difference in volume between group A and group C, group B and group C were statistically significant (p<0.001). Statistically significant positive correlation was found between age and volume of prostate (r = + 0.579, p < 0.001). Key Words: Prostate; volume; Bangladeshi. DOI: 10.3329/imcj.v4i2.6501Ibrahim Med. Coll. J. 2010; 4(2): 74-77

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