The value of plasma prolactin levels in the prediction of the responsiveness of growth hormone secretion to bromocriptine and TRH in acromegaly

Abstract

An increased plasma prolactin concentration in patients with acromegaly is accompanied in most patients by a higher sensitivity of growth hormone secretion to bromocriptine.

The role of prolactin in the inhibitory action of bromocriptine on growth hormone secretion in acromegaly

“…Liuzzi et al (1974b) showed that in general those acromegalie patient whose GH levels are inhibited by dopaminergic drugs also react to TRH with a paradoxical increase of GH secretion, while patients unresponsive to dopaminergic sti¬ muli were also unresponsive to TRH. This homo¬ geneity in the responsiveness of GH to bromo¬ criptine and TRH in acromegaly was seen in 86% (Liuzzi et al 1974b), 76% (Lamberts et al 1982) and 68% (present study) of the patients. This resemblance between the characteristic qualities of GH secretion in some acromegalics with those of normal Prl secretion, led several groups to suggest a role for Prl in the response of acromegalics to bromocriptine (Chiodini et al 1974;Lamberts et al 1976Lamberts et al , 1979Werner et al 1978).…”

“…We recently studied the relationship between the plasma prolactin (Prl) concentration of 79 un¬ treated acromegalie patients and the response of GH to bromocriptine (Lamberts et al 1982). Hyperprolactinaemia was present in 42% of these patients, and it was shown that an increased plasma Prl level is accompanied in most acromegalie pa¬ tients by a high sensitivity of GH secretion to bromocriptine in the acute test (Lamberts et al 1982), but also during chronic therapy (Lamberts In the present study the immunohistochemical presence or absence of Prl in pituitary tumour tissue of 35 transsphenoidally operated acrome¬ galie patients was correlated with the in vivo sens¬ itivity of GH secretion to bromocriptine and TRH.…”

Gene expression in pituitary adenomas: New insights

“…Growth hormone and PRL are commonly associated, up to 40% of patients with acromegaly having hyperprolactinaemia (Bassetti et al, 1986;Lamberts et al, 1982), often the result of production of both hormones by the tumour (Kanie et al, 1983). This may be from separate cell populations as in the mixed GH/PRL cell adenoma or from the same cells as in the mammosomatotroph adenoma .…”

MANAGEMENT OF ENDOCRINE DISEASE: GH excess: diagnosis and medical therapy

“…GH-secreting adenomas may be plurihormonal, and hyperprolactinaemia is found in 30-40% of acromegalic patients (54), and the adenoma may also co-secrete thyroid-stimulating hormone (TSH) and/or a-subunit (55). Reversible transdifferentiation, i.e.…”