1/6. Persistence of macroprolactinemia due to antiprolactin autoantibody before, during, and after pregnancy in a woman with systemic lupus erythematosus.A woman with systemic lupus erythematosus (SLE) with marked increases in circulating 150-kDa PRL was studied from before conception, throughout pregnancy, and after pregnancy. The clinical features of the patient included idiopathic hyperprolactinemia without clinical symptoms such as amenorrhea and galactorrhea before pregnancy. No clinical lupus activity was present during follow-up. serum PRL increase during pregnancy in this patient was considerably higher at weeks 27 and 33 than in normal pregnant women. In contrast, serum-free PRL levels were considerably lower at weeks 20, 27, and 33 than in normal pregnant women. A 150-kDa PRL (big big PRL) species persisted as the predominant circulating form of PRL throughout each measurement in this woman with SLE. In contrast, the predominant form of PRL in serum from healthy pregnant women was little PRL (or monomeric PRL). The nature of big big PRL was due to the presence of anti-PRL autoantibodies forming an IgG-23 kDa PRL complex, in accordance with the studies by affinity chromatography for IgG and Western blot analysis. The IgG-PRL complex was fully bioactive in vitro (Nb2 rat lymphoma cell assay). Injection of the serum into the rats demonstrated that the IgG-PRL complex was cleared more slowly than serum containing predominantly monomeric PRL. The data suggest that the IgG-PRL complex has biological activity; the absence of symptoms in this woman may be attributed to the fact that due to its large molecular weight, big big PRL does not easily cross the capillary walls. Delayed clearance may account for increased serum PRL levels in this SLE patient with anti-PRL autoantibodies.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
2/6. Heterogeneity of serum prolactin throughout the menstrual cycle and pregnancy in hyperprolactinemic women with normal ovarian function.We have demonstrated the selective secretion of high mol wt PRL series (big big PRL) in women with hyperprolactinemia and normal ovarian function. This observation suggests that big big PRL is immunologically similar, but biologically less active, than monomeric or little PRL. In this study we determined the molecular size heterogeneity of immunoreactive PRL in the serum from two ovulatory hyperprolactinemic women (subjects A and B) who had large amounts of serum big big PRL during a menstrual cycle and/or gestation. serum samples obtained throughout the menstrual cycle (days 6, 10, 14, 17, 23, and 28, taking as day 1 the first day of bleeding) and pregnancy (weeks 7, 9, 11, 15, 20, 25, 30, 34, and 38) were fractionated by gel filtration chromatography. PRL was identified in column eluates by specific RIA. Two additional pregnant women, one with a bromocriptine-treated PRL-secreting adenoma (subject C), and a normal woman (subject D) were studied. Big big PRL was the predominant species throughout the different phases of the menstrual cycle in subject B, comprising 70-80% of the total immunoreactive PRL. Most of the remainder was big PRL, and little PRL was present in only small amounts (6-12%) during the luteal phase. During their pregnancies, the serum PRL in subjects A and B initially was mostly big big PRL, but later in gestation the PRL composition shifted from the high mol wt variants to little PRL. The infant's cord (subject A) and peripheral (subject B) serum at birth contained appreciable quantities of big big and big PRL, respectively. These results indicate that structural changes in PRL occur during pregnancy and the menstrual cycle which are probably influenced by the hormonal environment. In addition, the occurrence of larger mol wt PRL species in the serum of the infant of a hyperprolactinemic mother suggests that the presence of high proportions of big big PRL in the serum is genetically determined.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
3/6. hyperthyroidism due to a thyroid-stimulating hormone (TSH)-secreting pituitary adenoma associated with functional hyperprolactinaemia. A case report.This paper reports the case of a 31-year-old woman with hyperthyroidism, increased TSH and thyroid hormone levels, evidence of a pituitary adenoma, hyperprolactinaemia, amenorrhoea, and galactorrhoea. Following trans-sphenoidal pituitary adenomectomy, mild hyperthyroidism and increased TSH and alpha subunit levels persisted, whereas hyperprolactinaemia, amenorrhoea, and galactorrhoea disappeared. serum TSH levels were not affected by administration of TRH, metochlopramide, domperidone, l-dopa or somatostatin. serum TSH chromatography showed a normal pattern. Following a second trans-sphenoidal pituitary adenomectomy and radiotherapy, hyperthyroidism disappeared, and the TSH and alpha subunit levels returned to normal. light microscopy showed no specific TSH immunostaining although electron microscopy revealed numerous secretory granules alined along the plasma membrane. The post-operative follow-up confirmed the presence of a TSH-secreting pituitary adenoma associated to functional hyperprolactinaemia.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
4/6. Identification of macroprolactin in a patient with asymptomatic hyperprolactinemia as a stable PRL-IgG complex.We characterize the molecular form of PRL in a female patient with asymptomatic, idiopathic hyperprolactinemia. Size exclusion chromatography revealed that PRL was present exclusively in the form of macroprolactin (> 200 kD mol wt). By immunoaffinity purification, Western blot analysis, and binding studies the molecule was identified as a PRL-IgG complex of extremely high stability. sequence analysis revealed no mutations in the protein coding region of the hPRL gene using hPRL cDNA amplified from the patient's peripheral blood lymphocytes. In spite of full bioactivity in vitro, as determined by Nb2 bioassay, the complex apparently lacks bioactivity in vivo. Its high molecular weight may reduce its access to target organs in the periphery as well as centrally.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
5/6. Changes in the prolactin serum isoforms secreted by a pituitary adenoma associated with therapy.Variations in serum molecular forms of prolactin (PRL) from an adolescent woman presenting amenorrhea-galactorrhea are reported. Persistent hyperprolactinemia and hypoestrogenism were demonstrated as well as the presence of a pituitary tumor with suprasellar extension. bromocriptine was given at progressive doses up to 37 mg daily, decreasing the hyperprolactinemia and galactorrhea. After 2 years of treatment the patient noticed symptoms of gastric intolerance, bromocriptine was discontinued and a rebound of hyperprolactinemia was observed. lisuride was administered instead resulting in a new decrease in PRL serum levels, disappearance of galactorrhea and beginning of regular menses. serum gel chromatographic analysis was carried out before and during lisuride treatment. The first chromatographic analysis showed a predominance of high molecular weight (approximately 66 KD) PRL, accounting for more than 90% of the immunoreactive PRL. The second chromatography showed the major peak of immunoreactive PRL displaced to the right (molecular weight of 22 KD), which was eluted near the PRL standard. With these chromatographic patterns it is concluded that the pituitary macroprolactinoma secreted different molecular forms of PRL and treatment with lisuride appeared to exert some effect on the PRL molecular size secreted by the pituitary.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
6/6. Asymptomatic 'big' hyperprolactinemia in two men with pituitary adenomas.'Big' and 'big-big' hyperprolactinemia, the presence of increased serum concentrations of high molecular weight (50-60 and 150 kDa respectively) prolactin forms, has mostly been reported in women with idiopathic hyperprolactinemia and normal hypothalamic-pituitary ovarian axis function. It has been suggested that both 'big' and 'big-big' prolactin species are biologically less active than the 22 kDa form predominating in normal individuals. We report the cases of two men with pituitary adenomas who were secreting significant amounts of 'big' (50-60 kDa) prolactin documented by Sephadex G-100 column chromatography. Both patients reported normal sexual function despite high prolactin levels. Results of nocturnal rigidity and tumescence testing were normal, confirming that significant hyperprolactinemia was not interfering with either patient's sexual function. 'Big' hyperprolactinemia should thus be suspected even in male patients with prolactin-secreting pituitary adenomas who maintain adequate sexual function in the presence of high prolactin levels.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |