Fleece growth in Australian cashmere goats. III. The seasonal patterns of cashmere and hair growth, and association with growth hormone, prolactin and thyroxine in blood

1993 ◽  
Vol 44 (5) ◽  
pp. 1035 ◽  
Author(s):  
WRL Kloren ◽  
BW Norton ◽  
MJ Waters
Keyword(s):  
Growth Hormone ◽  
Hair Growth ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Growth Cycle ◽  
Prolactin Secretion ◽  
Seasonal Patterns ◽  
Hormone Concentration ◽  
Active Growth ◽  
Cashmere Goats

The seasonal patterns of cashmere and hair growth, and prolactin, thyroxine and growth hormone concentration in blood were investigated in male, female and castrated male 6- month-old Australian cashmere goats for 27 months. Seasonal patterns of cashmere growth were distinct with length increasing from a minimum in December to maximum (50-60 mm) in July. Initiation of cashmere growth in female goats was consistently earlier than that of males, with that of castrates being similar, later and earlier than males in 1987, 1988 and 1989 respectively. The initiation of cashmere growth progressed in a wave from the hip to the shoulder (6 weeks). There were no significant effects of sex on maximum length of cashmere grown. Prolactin secretion was also seasonal, increasing from minimum values in July-August (20 ng/mL) to peak levels around December (50-350 ng/mL). Thyroxine concentrations were higher in summer than winter, but seasonal changes were not as distinct as those of prolactin. Growth hormone secretion was aseasonal, and declined with age. It has been proposed that peak levels of prolactin in December were associated with the initiation of cashmere growth, with active growth occurring as levels declined. Neither thyroxine nor growth hormone appear to have a regulatory influence on the cashmere growth cycle.

Invasive mixed growth hormone/prolactin secreting pituitary tumour: complete shrinking by octreotide and bromocriptine, and lack of tumour growth relapse 20 months after octreotide withdrawal

1992 ◽  
Vol 126 (2) ◽  
pp. 179-183 ◽  
Author(s):  
Jean-Louis Sadoul ◽  
Antoine Thyss ◽  
Pierre Freychet
Keyword(s):  
Growth Hormone ◽  
Tumour Growth ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Clinical Signs ◽  
Treatment Protocol ◽  
Pituitary Tumour ◽  
Prolactin Secretion ◽  
Close Monitoring ◽  
Complete Control

Octreotide and bromocriptine were used to treat an acromegalic patient harbouring an invasive pituitary tumour secreting growth hormone and prolactin. Octreotide (100 μg, subcutaneously, three times daily) and bromocriptine (15 mg orally, daily) rapidly improved clinical signs and symptoms, including diabetes that initially required insulin. Complete control of growth hormone and prolactin secretion was obtained and maintained by this treatment protocol for 12 months without affecting the other pituitary functions. A major tumour shrinkage was apparent by magnetic resonance imaging after six months, and was considered to be complete after 12 months of treatment. Octreotide was then discontinued without any relapse in either growth hormone secretion or tumour growth over a 20-month period following withdrawal. Attempts were made to discontinue bromocriptine, but a maintenance therapy (2.5 mg daily) was required to control rebounds of prolactin hypersecretion. Two months after octreotide withdrawal, acute pancreatitis secondary to cholelithiasis required surgery; this complication was attributed to octreotide (pre-treatment ultrasonography was normal). These findings suggest that combination therapy with octreotide and bromocriptine may be considered in pituitary macroadenomas secreting growth hormone and prolactin. They also emphasize the need for a close monitoring of cholelithiasis, not only during octreotide therapy but also after the drug's withdrawal.

DNA SYNTHESIS AND DEPLETION OF PROLACTIN IN THE PITUITARY GLAND OF THE MALE RAT

1978 ◽  
Vol 77 (1) ◽  
pp. 129-136 ◽  
Author(s):  
H. M. LLOYD ◽  
J. M. JACOBI ◽  
J. D. MEARES
Keyword(s):  
Growth Hormone ◽  
Dna Synthesis ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Prolactin Secretion ◽  
Male Rats ◽  
Male Rat ◽  
Serum Prolactin ◽  
Inhibitory Effects ◽  
Pituitary Prolactin

Haloperidol, bromocriptine and diethylstilboestrol dipropionate were given in various régimes to male rats to determine their effects on pituitary DNA synthesis, prolactin secretion and growth hormone secretion. Haloperidol increased serum prolactin but did not stimulate pituitary DNA synthesis or reduce pituitary prolactin concentrations. Haloperidol potentiated the effects of oestrogen on serum prolactin and on pituitary DNA synthesis; pituitary prolactin concentrations were greatly reduced, and growth hormone secretion was slightly inhibited. The inhibitory effects of bromocriptine in oestrogen-stimulated rats were demonstrated by smaller pituitary weights and decreased DNA synthesis; serum prolactin levels were lowered and pituitary prolactin concentrations were increased. Haloperidol, given to rats treated with oestrogen and bromocriptine, reversed the inhibitory effects of bromocriptine on DNA synthesis and serum prolactin; pituitary prolactin concentrations fell to well below normal. The results suggest that the haloperidol potentiation of oestrogeninduced pituitary DNA synthesis may depend upon stimulation of prolactin secretion together with reduction of intracellular prolactin levels.

scholarly journals Suppression of sleep-related prolactin secretion and enhancement of sleep-related growth hormone secretion.

1975 ◽  
Vol 56 (3) ◽  
pp. 690-697 ◽  
Author(s):  
W B Mendelson ◽  
L S Jacobs ◽  
J D Reichman ◽  
E Othmer ◽  
P E Cryer ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Prolactin Secretion

LONG-TERM TREATMENT OF ACROMEGALY WITH BROMOCRIPTINE

1978 ◽  
Vol 87 (4) ◽  
pp. 687-700 ◽  
Author(s):  
Peter Claes Eskildsen ◽  
Per Aaby Svendsen ◽  
Lisbeth Vang ◽  
Jørn Nerup
Keyword(s):  
Growth Hormone ◽  
Hormone Secretion ◽  
Visual Fields ◽  
Growth Hormone Secretion ◽  
Term Treatment ◽  
Prolactin Secretion ◽  
Plasma Growth Hormone ◽  
Free Cortisol ◽  
Long Term Treatment

ABSTRACT Treatment with bromocriptine, 30–55 mg daily, in 13 acromegalics for 1–15 months, resulted in a 60 % decrease in growth hormone secretion, as judged from the excretion of growth hormone in 24-h urine. Normal excretion was obtained in 10 patients, while 1 patient showed no response. The plasma growth hormone response to O-GTT was improved, but not normalized, in 4 of 7 patients treated for more than 6 months, and marked glucosuria disappeared in two diabetics. While the secretion of TSH, LH and FSH was unchanged, the prolactin secretion was inhibited. The urine excretion of free cortisol showed a 30 % decrease, possibly due to a direct effect of bromocriptine on the ACTH-secretion. Hypercalcaemia was never seen, but the initial hypercalcuria showed a modest decrease without measurable changes in the creatinine clearance. The subjective relief during long-term treatment was marked in 10 of 11 patients and the dominating symptoms disappeared in 40–67 %, whereas heal-pad thickness, enlarged sellae, and visual fields remained unchanged. No serious side effects were observed. Treatment with bromocriptine seems effective and should be considered as a remedy amongst others, in suitable cases of acromegaly.

scholarly journals Ghrelin-induced growth hormone secretion in humans

2000 ◽  
pp. R11-R14 ◽  
Author(s):  
R Peino ◽  
R Baldelli ◽  
J Rodriguez-Garcia ◽  
S Rodriguez-Segade ◽  
M Kojima ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Total Dose ◽  
Dose Response ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Prolactin Secretion ◽  
Gh Secretion ◽  
Relevant Dose

Ghrelin is a novel growth hormone (GH) releaser acylated peptide that has recently been purified from stomach, and which potently binds to the GH secretagogue receptor. Ghrelin releases GH in vitro and in vivo in animal models, however its actions, potency and specificity in humans are unknown. In the present study, 12 healthy subjects were studied: 6 underwent four tests with ghrelin administered i.v. at the dose of 0 (placebo), 0.25, 0.5 and 1 microg/kg which corresponds to 0, 18, 37 and 75 microg total dose. A further 6 volunteers underwent two tests on different days with ghrelin at the dose of 3.3 or 6.6 microg/kg which corresponds to 250 microg and 500 microg total dose. Ghrelin-mediated GH secretion showed a dose-response curve, in which 1 microg/kg was the minimally effective dose in some individuals, but not as a group. On the contrary, the total doses of 250 microg and 500 microg elicited a powerful GH secretion, with a mean peak of 69.8+/-9.2 microg/l and 90.9+/-16.9 microg/l respectively, and areas under the curve of 4435+/-608 and 6125+/-1008 microg/l per 120 min respectively. All of them statistically significant vs placebo and vs the 1 microg/kg dose. Ghrelin administration also elicited a relevant dose-response mediated prolactin secretion suggesting no specificity of its actions. No relevant side effects were observed with ghrelin apart from a hyperhydrosis episode in two individuals tested with the higher ghrelin doses. In conclusion, ghrelin is a potent releaser of GH in normal individuals, with a dose-response pattern of operation. No saturating dose was observed.

THE EFFECT OF BETA-RECEPTOR BLOCKADE ON EXERCISE AND ARGININE-INDUCED GROWTH HORMONE SECRETION IN MAN

1974 ◽  
Vol 77 (1_Suppl) ◽  
pp. S6 ◽  
Author(s):  
S. Raptis ◽  
H. Hirth-Schmidt ◽  
K. E. Schröder ◽  
E. F. Pfeiffer
Keyword(s):  
Growth Hormone ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Receptor Blockade ◽  
Beta Receptor ◽  
Beta Receptor Blockade

Growth hormone secretion in children treated for medulloblastoma

2018 ◽  
Author(s):  
Alexey Kalinin ◽  
Natalia Strebkova ◽  
Olga Zheludkova ◽  
Maria Kareva
Keyword(s):  
Growth Hormone ◽  
Hormone Secretion ◽  
Growth Hormone Secretion
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