THE DYNAMICS OF GROWTH HORMONE AND PROLACTIN SECRETION IN ACROMEGALIC PATIENTS WITH "MIXED" PITUITARY TUMOURS

1979 ◽  
Vol 90 (2) ◽  
pp. 198-210 ◽  
Author(s):  
Steven W. J. Lamberts ◽  
Jan G. M. Klijn ◽  
Giok H. Kwa ◽  
Jan C. Birkenhäger

ABSTRACT The dynamics of growth hormone (GH) and prolactin (PRL) secretion in response to thyrotrophin-releasing hormone (TRH) and bromocriptine were evaluated in 15 untreated and 1 previously unsuccessfully treated patients with acromegaly. In 7 of these patients elevated basal PRL levels were found. In 4 of the 7 hyperprolactinaemic patients plasma PRL concentrations followed closely the pattern of GH secretion in response to TRH (400 μg). The maximal paradoxical increment of GH in response to TRH was paralleled by a delayed PRL response, while a close relationship was observed between the suppression of the elevated GH and PRL levels in these patients after one single dose of 2.5 mg bromocriptine. In one of these patients parallel escapes of plasma GH and PRL during bromocriptine treatment were seen. In addition, a significant higher sensitivity to the GH-lowering effect of 2.5 mg bromocriptine was noted from 2 up to 8 h in these 4 patients with presumably "mixed" GH/PRL secreting pituitary adenomas, compared with the response in 9 untreated acromegalic patients with normal basal PRL levels. In the 3 acromegalic patients with slightly elevated PRL levels, no or a normal increase of PRL levels in response to TRH was observed, while the suppressive effect of bromocriptine on plasma GH concentrations was not different from that seen in the acromegalic patients with normal PRL levels. However, as a group the 7 patients with hyperprolactinaemia showed a significantly higher GH-lowering effect to 2.5 mg bromocriptine than the 9 normoprolactinaemic acromegalic patients. A close relationship between the magnitude of the increment of GH in response to TRH and the decrease of plasma GH after 2.5 mg bromocriptine was present in the whole group of 16 acromegalics (P < 0.01). No such correlation was shown in the type of response of plasma GH to an oral glucose load or the coefficient of variation of basal plasma GH levels on 5 different days. It is concluded that in the population of acromegalic patients with elevated plasma PRL levels a sub-population of patients is present with "mixed" pituitary adenomas which secrete GH and PRL in a parallel manner. The characteristics of the secretion of both hormones, in these patients can be recognized as a parallel, delayed response of both hormones to TRH and an increased sensitivity to the suppressive effect of bromocriptine.

1976 ◽  
Vol 81 (1) ◽  
pp. 1-8 ◽  
Author(s):  
K. Maeda ◽  
Y. Kato ◽  
N. Yamaguchi ◽  
K. Chihara ◽  
S. Ohgo ◽  
...  

ABSTRACT The effect of thyrotrophin-releasing hormone (TRH) or luteinizing hormone-releasing hormone (LH-RH) on plasma levels of growth hormone (GH), prolactin (PRL), thyrotrophin (TSH), and luteinizing hormone (LH), were studied in patients with anorexia nervosa. The basal plasma GH levels were elevated in 6 of 11 patients studied. Intravenous injection of synthetic TRH (500 μg) significantly raised the plasma GH levels in 9 of 11 patients. The peak values of plasma GH after TRH ranged from 6.0 to 31.5 ng/ml. Plasma GH concentrations also increased following the administration of synthetic LH-RH (100μg) in 1 of 7 patients. The intravenous injection of saline solution caused no significant change in plasma GH in these patients. The plasma LH responses to LH-RH were significantly blunted in all patients, whereas the plasma PRL and TSH responses to TRH were almost normal in the patients examined. These results suggest that the hypothalamo-pituitary function regulating GH and LH secretion is altered in patients with anorexia nervosa.


2010 ◽  
Vol 29 (4) ◽  
pp. E5 ◽  
Author(s):  
Peter G. Campbell ◽  
Erin Kenning ◽  
David W. Andrews ◽  
Sanjay Yadla ◽  
Marc Rosen ◽  
...  

Object Using strict biochemical remission criteria, the authors assessed surgical outcomes after endoscopic transsphenoidal resection of growth hormone (GH)–secreting pituitary adenomas and identified preoperative factors that significantly influence the rate of remission. Methods A retrospective review of a prospectively maintained database was performed. The authors reviewed cases in which an endoscopic resection of GH-secreting pituitary adenomas was performed. The cohort consisted of 26 patients who had been followed for 3–60 months (mean 24.5 months). The thresholds of an age-appropriate, normalized insulin-like growth factor–I concentration, a nadir GH level after oral glucose load of less than 1.0 μg/l, and a random GH value of less than 2.5 μg/l were required to establish biochemical cure postoperatively. Results Overall, in 57.7% of patients undergoing a purely endoscopic transsphenoidal pituitary adenectomy for acromegaly, an endocrinological cure was achieved. The mean clinical follow-up duration was 24.5 months. In patients with microadenomas (4 cases) the cure rate was 75%, whereas in patients harboring macroadenomas (22 cases) the cure rate was 54.5%. Cavernous sinus invasion (Knosp Grades 3 and 4) was associated with a significantly lower remission rate (p = 0.0068). Hardy Grade 3 and 4 tumors were also less likely to achieve biochemical cure (p = 0.013). The overall complication rate was 11.5% including 2 incidents of transient diabetes insipidus and 1 postoperative CSF leak, which were treated nonoperatively. Conclusions A purely endoscopic transsphenoidal approach to GH-secreting pituitary adenomas leads to similar outcome for noninvasive macroadenomas compared with traditional microsurgical techniques. Furthermore, this approach may often provide maximal visualization of the tumor, the pituitary gland, and the surrounding neurovascular structures.


1982 ◽  
Vol 99 (3) ◽  
pp. 344-351 ◽  
Author(s):  
Abraham Martinez-Campos ◽  
Paolo Giovannini ◽  
Antonello Novelli ◽  
Daniela Cocchi ◽  
Tommaso Caraceni ◽  
...  

Abstract. The thyrotrophin (TSH) and prolactin (Prl)-releasing effects of TSH-releasing hormone (TRH) were investigated in 20 subjects with Parkinson's disease (PD), unmedicated, on chronic treatment with a combination levodopa-benserazide (Madopar) or levodopa-carbidopa (Sinemet) or withdrawn from therapy. Administration of TRH (200 μg iv) induced in unmedicated patients TSH and Prl responses significantly lower than those of sex-and age-matched controls. In patients on Madopar therapy the TSH and Prl responses to TRH were greater than in unmedicated patients and comparable to those of controls, while in patients on Sinemet therapy the pituitary responses were undistinguishable from those of unmedicated subjects. Withdrawal of Madopar therapy resulted in a marked diminution of the TSH response but did not affect the Prl response to TRH. Withdrawal of Sinemet therapy did not alter the TSH and Prl responses to TRH. Concomitant evaluation of growth hormone (GH) levels, in none of the subjects evidenced non-specific changes in plasma GH following TRH. Since TSH and Prl responses to TRH are inhibited by an enhancement of the dopaminergic tone, it would appear that the latter is preserved in the tuberoinfundibular system of unmedicated subjects and subjects on chronic Sinemet therapy, but is defective in subjects on chronic Madopar therapy.


1988 ◽  
Vol 118 (2) ◽  
pp. 233-236 ◽  
Author(s):  
E. R. Kühn ◽  
A. Vanderpooten ◽  
L. M. Huybrechts ◽  
E. Decuypere ◽  
V. Darras ◽  
...  

ABSTRACT Plasma GH, tri-iodothyronine (T3), thyroxine (T4) and liver 5′-monodeiodination (5′-D) activity were measured in 18-day-old chick embryos injected with thyrotrophin-releasing hormone (TRH) and human pancreatic growth hormone releasing factor (hpGRF). Injections of 0·1 and 1 μg TRH and 1·5 μg hpGRF increased the concentration of plasma GH while injection of 15 μg hpGRF had no effect. Concentrations of plasma T3 were raised after injection of TRH or hpGRF. Injections of TRH but not of hpGRF raised the concentration of plasma T4. The increases in concentration of plasma T3 after injection of TRH or hpGRF were parallelled by increases in liver 5′-D activity. An injection of 0·25 μg T4 significantly raised the concentration of T4 in plasma but had no effect on plasma T3 or liver 5′-D activity. It is concluded that the release of chicken GH by TRH or hpGRF is responsible for the observed increases in plasma concentration of T3 and liver 5′-D activity. J. Endocr. (1988) 118, 233–236


2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Hatem Eid

Abstract Introduction: Secreting pituitary adenoma is exceedingly rare. Less than 15 cases having been reported. Its clinical presentation and diagnosis is challenging. We report a case of pituitary macroadenoma, with features of acromegaly and hyperthyroidism. Case report: A 75 years’ old man presented with new onset atrial fibrillation. He had high FT4 with normal TSH. His ultrasound scan of the neck showed a solitary nodule. He had ablation twice and was started on bisoprolol and anticoagulant. He had MRI scan for headaches and this showed a pituitary macroadenoma. He had high IGF-1. His oral glucose tolerance showed failure of GH suppression. His FT4 was persistently high with normal TSH and he had high a subunits. This suggested the diagnosis of TSH and GH secreting pituitary adenoma. Discussion: TSH-secreting pituitary adenomas are rare and not uncommonly, they co-secrete other pituitary hormones including growth hormones. Somatotrophs and lactotrops share common transcription factors with thyrotrophs. TSH-secreting adenomas are benign but 60% of them are locally invasive. TSH-secreting pituitary adenomas typically present with either symptoms of tumor growth like headache or visual field disturbance or symptoms of hyperthyroidism. Thyroid nodules are common in patients with TSHomas. In patients with TSH-secreting pituitary adenomas, majority will need only surgery and radiation. The medical treatment used to normalize TSH and FT4 levels is somatostatin analogs. This is effective in about 90% of patients with TSH secreting pituitary adenomas TSHoma should be differentiated from resistance to thyroid (RTH). The main difference between TSHoma and RTH is the presence of signs and symptoms of hyperthyroidism in patients with TSHoma, absence of a family history, normal thyroid hormone levels in family members, and the presence of an elevated glycoprotein α-subunit in patients with pituitary tumor. Reference: H Adams and D Adams. A case of a co-secreting TSH and growth hormone pituitary adenoma presenting with a thyroid nodule. EDM case reports 2018 [email protected]


1977 ◽  
Author(s):  
K. E. Sarji ◽  
H. B. Schraibman ◽  
J. H. Levine ◽  
M. Barnes ◽  
R. M. G. Nair ◽  
...  

Growth hormone (GH) has been implicated in the pathogenesis of diabetic angiopathy although the exact mechanism remains unknown, von Willebrand factor activity (vWF) is significantly higher in diabetic than in normal plasma (p<.001). In view of this, we have investigated the relationship of radioimmunoassayable GH and vWF activity, as measured in a bioassay using washed normal human platelets and ristocetin. Samples were obtained after an overnight fast, during oral glucose tolerance tests, and during sleep. A significant positive correlation was seen between GH over a range of 0.46 to 12.2 ng/ml and vWF activity over a range of 1 to 470% (p<.01). vWF activity was suppressed by oral glucose in normals and diabetics, with the amount of suppression related to the degree of glucose intolerance. Maximal suppression of vWF activity was coincident with maximal GH suppression. Samples from 4 normal subjects drawn through an indwelling catheter at 30-minute intervals during sleep showed peaks of plasma GH and vWF activity with GH peaks preceding vWF peaks by an hour or less. Two patients with panhypopituitarism and one patient with isolated GH deficiency were similarly studied. GH levels were low in these patients, but vWF levels were normal; both GH and vWF showed little sleep-related change.A single intramuscular injection of GH produced a marked increase of vWF activity in all 3 patients within 30 minutes and a later increase after 5–6 hours. We conclude that a regulator of glucose metabolism, possibly GH, is involved in regulation of vWF activity.


1983 ◽  
Vol 103 (4) ◽  
pp. 446-450 ◽  
Author(s):  
S. W. J. Lamberts ◽  
J. G. M. Klijn ◽  
C. C. J. van Vroonhoven ◽  
S. Z. Stefanko ◽  
A. Liuzzi

Abstract. Bromocriptine treatment results in clinical improvement and inhibition of plasma GH levels in only part of the acromegalic patients. The possible role of the simultaneous presence of Prl and GH in GH-secreting pituitary adenomas was investigated with regard to the inhibitory action of bromocriptine on GH secretion and the paradoxical increase of GH release in reaction to TRH. Surgically obtained pituitary tumour tissue from 35 consecutive acromegalic patients was studied immunohistochemically. In 21 patients no Prl was present in the tumour tissue. These patients had normal plasma Prl levels. In the other 14 patients Prl was present in the tumour tissue. Hyperprolactinaemia was found in 10 of these 14 patients. Plasma GH levels from 2 till 10 h after the administration of 2.5 mg bromocriptine measured before operation were significantly more suppressed in the patients with mixed GH/Prl-containing than in those with pure GH-containing pituitary adenomas, being 38 ± 4% and 65 ± 4% of basal values, respectively (P< 0.01). The response of GH to TRH, however, did not differ significantly between the two groups. Conclusions: 1. In about 70% of patients with 'mixed' GH/Prl containing adenomas, hyperprolactinaemia is present. 2. The simultaneous presence of Prl and GH in a GH-secreting pituitary tumour increases the sensitivity of GH secretion to bromocriptine. 3. The plasma Prl level is of value to predict which patients with acromegaly are likely to respond to bromocriptine with an inhibition of GH secretion.


1994 ◽  
Vol 140 (3) ◽  
pp. 495-502 ◽  
Author(s):  
T P Fletcher ◽  
I J Clarke

Abstract This study examined the effect of thyroidectomy (TX) on the GH axis in sheep. The secretion of GH was monitored 10 and 77 days after TX or sham-TX when the effects on plasma GH and prolactin levels of the injection of 0·5 μg GH-releasing factor (GRF)/kg and 1 μg thyrotrophin-releasing hormone (TRH)/kg were also assessed. There were no significant differences in GH pulse amplitude, pulse frequency, inter-pulse interval and GH secreted/h between sham-TX and TX animals at 10 or 77 days after TX. There was no difference in the GH response to GRF injection in sham-TX sheep at any time but in TX sheep the GH response was significantly (P<0·05) attenuated 10 days after TX. After 77 days the GH response was similar to the response before TX. There was no measurable GH response to injection of TRH in sham-operated or TX sheep at any time. The prolactin response to TRH was not affected by TX or sham-TX. These results suggest that TX in sheep does not affect GH secretion but paradoxically the response to GRF is attenuated in hypothyroid sheep in the short term. TRH causes release of prolactin but not GH in sheep. Journal of Endocrinology (1994) 140, 495–502


Sign in / Sign up

Export Citation Format

Share Document