Characterization of big, big prolactin in patients with hyperprolactinaemia

@article{Lelte1992CharacterizationOB,
  title={Characterization of big, big prolactin in patients with hyperprolactinaemia},
  author={Valerlano Lelte and H Cosby and Lu{\'i}s Gonçalves Sobrinho and Agnes Fresnoza and M. A. Santos and Henry G. Frlesen},
  journal={Clinical Endocrinology},
  year={1992},
  volume={37}
}
OBJECTIVE The present study was designed to characterize the clinical findings of patients with macroprolactin‐aemia (sustained hyperprolactinaemia where the predominant form of prolactin is of large molecular size) and to further assess the bioactivity and structure of big, big prolactin (BB‐PRL). 

Anti‐prolactin (PRL) autoantibodies suppress PRL bioactivity in patients with macroprolactinaemia

The causes of the discrepancy in serum bioactive PRL concentrations in vitro measured by the Nb2 bioassay are investigated and the true biological features of macroprolactin are investigated.

Clinical and radiological features of patients with macroprolactinaemia

Macroprolactin is a complex of prolactin (PRL) and IgG and may account for a significant proportion of cases of ‘idiopathic hyperprolACTinaemia’ and is investigated and managed with a view to determining how patients with macroProlactinaemia should be investigated andmanaged.

The TSH response to domperidone reflects the biological activity of prolactin in macroprolactinaemia and hyperprolactinaemia

objective  To test the hypothesis that patients with hyperprolactinaemia due to biologically inactive macroprolactin will not show the characteristically increased dopaminergic inhibition of TSH

Characterization of macroprolactin and assessment of markers of autoimmunity in macroprolactinaemic patients

This study further characterizes macro Prolactin and evaluates for other markers of autoimmunity using a cohort of macroprolactinaemic sera.

Hyperprolactinemia with normal serum prolactin: Its clinical significance

The answer lies in the heterogeneity of the peptide hormone - the immunoactive and the bioactive forms.

Patients with macroprolactinaemia: clinical and radiological features

The aim of this study was to investigate the clinical and neuroradiological characteristics of patients with and without macroprolactinaemia and to evaluate the impact of macro Prolactin determination on the diagnostic work‐up of hyperprolACTinaemic patients.

Clinical relevance of macroprolactin

The anterior pituitary hormone PRL was identified in animal species as early as 1933 but only purified in humans in 1972, and has an estimated prevalence of 15% in women with secondary amenorrhoea and infertility in women and reduced libido, impotence and galactor rhoea in men.

Hyperprolactinaemia and verapamil: prevalence and potential association with hypogonadism in men

This data indicates that the prevalence and degree of hyperprolactinaemia associated with verapamil in the clinical setting is higher in patients treated with this drug than in those treated with placebo.

Symptoms of hyperprolactinemia with normal serum prolactin: is treatment required? -

Patients with menstrual abnormalities like oligomenorrhea or amenorrhea point towards a provisional diagnosis of increased serum prolactin levels or hyperprolactinemia, but patients can have all the features of hyper Prolactininemia with normal serum prolACTin levels.

CLINICAL EXPRESSION OF BIG-BIG PROLACTIN AND INFLUENCE OF MACROPROLACTINEMIA UPON IMMUNODIAGNOSTIC TESTS

In these patients, macroprolactinemia had clinical expression, but weaker than in true hyperProlactinemic patients, which determines high apparent variability of serum PRL level in current commercial assays.
...

References

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The present work provides evidence for the following conclusions: 1) the PRL responses to thyrotropin-releasing hormone and to domperidone merely bring additional diagnostic information relative to basal PRL levels in the occasional patients with macroprolactinemia; there is a continuous spectrum of lactotroph activities in women.

Maintained fertility in a patient with hyperprolactinemia due to big, big prolactin.

Reports that suggest big, big PRL has a low receptor affinity may account for the apparent lack of any biological effect upon Patient A from her sustained hyperprolactinemia, and possible immunological differences among the three forms of the circulating hormone are suggested.

Characterization of a large molecular weight prolactin in women with idiopathic hyperprolactinemia and normal menses.

The presence of a large molecular sized PRL as the major form of circulating immunoactive PRL in five women with idiopathic hyperprolactinemia and normal menses and diminished activity in the Nb2 rat lymphoma line revealed diminished activity compared to the 22,000-dalton species.

Detailed assessment of big big prolactin in women with hyperprolactinemia and normal ovarian function.

The data indicate that plasma concentrations of BBPRL may vary under the influence of a number of factors, but are much less sensitive to TRH stimulation, bromocriptine suppression, pregnancy, and suckling than PRL.

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There was a lack of correlation between big, medium, and small hPRL in samples obtained before and 1 yr after surgery, and it seems that only small and possibly medium PRL are secretory products.

Heterogeneity of pituitary and plasma prolactin in man: decreased affinity of "Big" prolactin in a radioreceptor assay and evidence for its secretion.

Molecular heterogeneity of immunoreactive human PRL (IR-hPRL) plasma was assessed by exclusion chromatography on Sephadex G-100 in blood drawn from 4 normal adults, 3 newborn infants, 2 late

Heterogeneity of serum prolactin throughout the menstrual cycle and pregnancy in hyperprolactinemic women with normal ovarian function.

The selective secretion of high mol wt PRL series (big big PRL) in women with hyperprolactinemia and normal ovarian function is demonstrated and indicates that structural changes in PRL occur during pregnancy and the menstrual cycle which are probably influenced by the hormonal environment.