Radioreceptor assay of serum prolactin using nitrocellulose membrane-immobilized mammary prolactin receptor

1992 ◽  
Vol 200 (1) ◽  
pp. 42-46 ◽  
Author(s):  
Maki Suzuki ◽  
Kaoru Kohmoto ◽  
Senkiti Sakai
Keyword(s):  
Prolactin Receptor ◽  
Radioreceptor Assay ◽  
Serum Prolactin ◽  
Nitrocellulose Membrane

Effects of long-term administration of high doses of medroxyprogesterone acetate on hormone receptors and target organs in the female rat

1984 ◽  
Vol 103 (3) ◽  
pp. 287-293 ◽  
Author(s):  
F. Di Carlo ◽  
S. Racca ◽  
G. Conti ◽  
E. Gallo ◽  
G. Muccioli ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Medroxyprogesterone Acetate ◽  
Prolactin Receptor ◽  
Female Rats ◽  
Serum Prolactin ◽  
Target Organs ◽  
Term Administration ◽  
Pituitary Glands ◽  
High Doses

ABSTRACT The changes in oestrogen, progesterone and prolactin receptor levels in target organs, and the macroscopic and microscopic modifications of uterus, ovary, adrenal and pituitary gland induced by long-term administration of high doses of medroxyprogesterone acetate (MPA) were investigated in female rats. Medroxyprogesterone acetate was injected i.m. for 30 days at daily doses of 7·5, 15 and 75 mg/kg. Oestrogen and/or progesterone-binding capacities were remarkably reduced at all doses of MPA used both in the uterus and pituitary gland. Furthermore, MPA caused a very evident reduction in the weight of pituitary glands, ovaries, adrenals and uterus. In all MPA-treated rats corpora lutea were absent from the ovaries, whereas the adrenals showed a significant reduction in the thickness of the cortex. In accordance with this, there was no evidence of ACTH-producing cells in the pituitary glands. Prolactin-producing cells were also absent, while GH-producing cells were present. Serum prolactin levels were significantly reduced at all doses of MPA used. A dramatic reduction of prolactin receptor concentrations was observed in the liver and the ovaries of MPA-treated rats. The results suggest that MPA acts as an antioestrogenic drug both by reducing the number of oestrogen receptors in target tissues and by changing the structure (and perhaps the function) of those organs (pituitary glands, ovaries and adrenals) which are, directly or indirectly, a source of oestrogens. The decreased synthesis of prolactin and the reduction of the number of prolactin receptors (which, on the contrary, are both increased by oestrogens) might be considered as additional antioestrogenic effects of MPA. J. Endocr. (1984) 103, 287–293

Serum Prolactin Contributes to Enhancing Prolactin Receptor and pJAK2 in Type I Endometrial Cancer Cells in Young Women Without Insulin Resistance

2019 ◽  
Vol 38 (4) ◽  
pp. 318-325 ◽  
Author(s):  
Chimeddulam Erdenebaatar ◽  
Munekage Yamaguchi ◽  
Mahina Monsur ◽  
Fumitaka Saito ◽  
Ritsuo Honda ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Endometrial Cancer ◽  
Cancer Cells ◽  
Young Women ◽  
Prolactin Receptor ◽  
Serum Prolactin ◽  
Type I

Biological Activity of Serum Prolactin in Patients with Primary Hypothyroidism

1988 ◽  
Vol 25 (5) ◽  
pp. 540-545 ◽  
Author(s):  
Caroline R Smith ◽  
Joan Butler ◽  
Michael R Norman
Keyword(s):  
Biological Activity ◽  
Primary Hypothyroidism ◽  
Radioreceptor Assay ◽  
Lymphoma Cell ◽  
Serum Prolactin ◽  
Control Subjects ◽  
Cell Assay ◽  
Essentially Normal ◽  
And Control ◽  
Hypothyroid Patients

Prolactin bioactivity was measured in sera from 22 patients with primary hypothyroidism and 13 euthyroid control subjects and compared with estimates of immunoactivity given by radioimmunoassay. The Nb2 rat lymphoma cell assay was modified to improve specificity for prolactin and used to measure bioactivity. Results of serum prolactin levels obtained using the bioassay were closely correlated with radioimmunoassay results in both hypothyroid patients and control subjects. Mean bioactivity/immunoactivity ratios in patients were not significantly different from those in control subjects. Mean prolactin concentration measured by both assays was significantly higher in patients than control subjects. Serum prolactin in patients with primary hypothyroidism appears to have essentially normal bioactivity as measured in the Nb2 assay, in contrast with a report of major differences between activity in radioreceptor assay and RIA in hypothyroid patients.

Lactogenic actions of different growth hormone preparations in pregnant and lactating rats

1994 ◽  
Vol 142 (3) ◽  
pp. 535-545 ◽  
Author(s):  
R W Carón ◽  
G A Jahn ◽  
R P Deis
Keyword(s):  
Milk Production ◽  
Prolactin Receptor ◽  
The Other ◽  
Serum Prolactin ◽  
Partial Action ◽  
Pregnant Rats ◽  
Liver Membranes ◽  
Ovine Prolactin ◽  
Lower Capacity ◽  
Partial Reversion

Abstract We studied the capacity of different GH preparations, natural human (h)GH, recombinant hGH (rhGH), rat (r)GH, ovine (o)GH, bovine (b)GH and porcine (p)GH, and ovine prolactin (oPRL), to stimulate lactogenesis in ovario-hysterectomized pregnant rats or intact lactating rats treated with bromocriptine (BC). Ovariohysterectomy (OVX-HYS) performed at 0800 h on day 19 of pregnancy induced lactogenesis, i.e. increases in mammary casein and lactose and positive response to the oxytocin test, 28 h later. Lactogenesis was prevented by treatment with BC (1·5 mg/kg) immediately after surgery (OVX-HYS-BC). The hormones were given at doses of 0·25 or 0·5 mg/rat (except rhGH given only at 0·5 mg/rat) at 1200 and 2000 h on day 19. Casein was increased by both doses of oPRL and hGH, rhGH and 0·25 mg oGH, and lactose by both doses of oPRL, rhGH and 0·25 mg rGH. The other GH preparations had no effect. The oxytocin test demonstrated the presence of milk in the mammary tissues of the OVX-HYS rats and in the OVX-HYS-BC plus oPRL (0·25 and 0·5 mg) or rhGH-treated groups. Injection of BC to pregnant rats at 2000 h on day 20 and at 0800 h on day 21 decreased litter growth on the first 4 days postpartum. Two-thirds of the litters resumed growth after day 4, indicating the recuperation of milk production, while the rest never recuperated. Serum prolactin in BC-treated rats was reduced until day 4 postpartum. On day 6 the rats which had recuperated had normal values, while those which had still not recuperated had lower values. BC-treated rats were injected s.c. with 0·25 mg each of oPRL, hGH, rGH, oGH, bGH or pGH, or 0·25 or 0·5 mg rhGH/rat, immediately postpartum and 12, 24 and 36 h later. hGH and 0·5 mg rhGH induced levels of milk production similar to controls except on day 3. oPRL and rhGH (0·25 mg), induced a partial reversion of the effect of BC. rGH and oGH had a slight effect on days 1 and 2 and all the litters resumed growth on day 7. In contrast, pGH and bGH were inactive. The affinity of hGH for the prolactin receptor, measured as displacement of 125I-labelled oPRL binding to crude liver membranes, was comparable with that of oPRL. While rhGH was ten times less active than oPRL, rPRL was 100 times lower and all the other GH preparations had at least 104 times lower capacity to displace 125I-labelled oPRL. These results indicate that both natural and recombinant hGHs are potent inductors of milk synthesis in pregnant or lactating rats, most probably due to their actions at the level of the prolactin receptor. rGH and oGH have a partial action, while pGH and bGH seem to be inactive. The actions of non-human GHs may be explained by their somatogenic properties exclusively, and indicate that GH may play a role in the optimization of milk production during lactation and an accessory role in the induction of lactogenesis in pregnant rats. Journal of Endocrinology (1994) 142, 535–545

scholarly journals Determination of Chlorpromazine in Serum by Radioreceptor Assay and HPLC

1986 ◽  
Vol 23 (3) ◽  
pp. 340-345 ◽  
Author(s):  
J Krska ◽  
G M Addison ◽  
S D Soni
Keyword(s):  
Parent Drug ◽  
Hplc Method ◽  
Radioreceptor Assay ◽  
Serum Prolactin ◽  
Active Metabolites ◽  
Serum Prolactin Level ◽  
Serum Samples ◽  
Blocking Activity ◽  
Schizophrenic Patients

A radioreceptor assay for chlorpromazine in serum, which is based on binding to dopamine receptors, is described. This method has been postulated to measure all active metabolites as well as the parent drug. We have compared this method with an HPLC method for chlorpromazine. Dopamine-blocking activity, measured in serum samples from schizophrenic patients receiving chlorpromazine, was 1·85–9·1 times higher than serum chlorpromazine level measured by HPLC. The correlation between the two methods was 0·75. Dopamine-blocking activity was related more closely to dose of drug and to serum prolactin level than was serum chlorpromazine level measured by HPLC.

scholarly journals Prolactin Enhances the Proliferation of Proliferative Endometrial Glandular Cells and Endometrial Cancer Cells

2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Munekage Yamaguchi ◽  
Chimeddulam Erdenebaatar ◽  
Fumitaka Saito ◽  
Ritsuo Honda ◽  
Takashi Ohba ◽  
...  
Keyword(s):  
Endometrial Cancer ◽  
Menstrual Cycle ◽  
Cell Lines ◽  
Estrogen Receptor Alpha ◽  
Prolactin Receptor ◽  
Receptor Expression ◽  
Serum Prolactin ◽  
Long Term Effects ◽  
Ishikawa Cells ◽  
Glandular Cells

Abstract To elucidate the mechanism of endometrial cancer (EC) development in young hyperprolactinemic women, this study assessed the hormonal receptor expression, proliferation, and signaling induced by prolactin in endometrial glands (EG) and EC. Prolactin receptor (PRLR) and estrogen receptor alpha (ER-α) in EG were evaluated during the menstrual cycle by immunohistochemistry. The following parameters were compared between EM-E6/E7/TERT cells, which originated from proliferative EG and Ishikawa cells. The expression levels of PRLR, pJAK2 (phosphorylated Janus Activating Kinase 2), its downstream pathways (MAPK, PI3K, and STAT), and ER-α were assessed after adding prolactin by Western blotting. U0126 was used as a MAPK inhibitor. The proliferation caused by estradiol was also examined by MTS assay after adding prolactin. PRLR expression in the EG was significantly higher in the proliferative phase than in the secretory phase, and it was correlated with ER-α expression during the menstrual cycle. After adding prolactin, the expression of pJAK2, PRLR and ER-α was significantly increased in both cell lines, MAPK was activated after adding prolactin in both cell lines, and PI3K and STAT were activated only in EM-E6/E7/TERT cells. The increased proliferation induced by estradiol was enhanced after adding prolactin in both cell lines. All changes caused by prolactin were inhibited in Ishikawa cells pretreated with U0126. Long-term effects of serum prolactin on persistent proliferative endometrium in the presence of estradiol may induce abnormal proliferation of EG in hyperprolactinemic women. Prolactin-PRLR signaling via MAPK may play a crucial role in the progression of EC in hyperprolactinemic women.

Depot Neuroleptic Medication and Serum Levels by Radioreceptor Assay: Prolactin Concentration, Electrocardiogram Abnormalities and Six-Month Outcome

1987 ◽  
Vol 21 (3) ◽  
pp. 327-338
Author(s):  
John Turbott ◽  
John Villiger ◽  
Lynley Hunter
Keyword(s):  
Serum Levels ◽  
Radioreceptor Assay ◽  
Clinical State ◽  
Serum Prolactin ◽  
Chronic Patients ◽  
Fluphenazine Decanoate ◽  
Schizophrenic Patients ◽  
Depot Neuroleptic ◽  
Electrocardiogram Ecg ◽  
Flupenthixol Decanoate

Twenty-six chronic schizophrenic patients on well-established depot neuroleptic regimes with stable doses (16 on fluphenazine decanoate, 10 on flupenthixol decanoate) had serum neuroleptic levels measured by radioreceptor assay (RRA) and were followed for six months. The serum prolactin (PRL) concentration and resting electrocardiogram (ECG) were also taken at the beginning of the study period. Correlations had previously been noted between RRA measured neuroleptic levels and outcome in both acute and chronic patients on oral medication. However, in this study of depot medication no significant correlations were found between serum neuroleptic concentration, serum prolactin concentration and the clinical state or outcome. The prevalence (33%) and type of ECG abnormality observed was similar to that previously reported.

A pilot phase II trial of cabergoline in the treatment of metastatic breast cancer.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e12568-e12568
Author(s):  
Ricardo Lima Barros Costa ◽  
Cesar Augusto Santa-Maria ◽  
Denise M. Scholtens ◽  
Sarika Jain ◽  
William John Gradishar ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Metastatic Breast Cancer ◽  
Phase Ii ◽  
Prolactin Receptor ◽  
Metastatic Breast ◽  
Receptor Expression ◽  
Serum Prolactin ◽  
Dopamine Receptor Agonist ◽  
Pilot Phase ◽  
Measurable Disease

e12568 Background: The prolactin receptor can be overexpressed in breast cancer, and pre-clinical data indicate that it contributes to the pathobiology of breast cancer. Cabergoline is a potent dopamine receptor agonist of D2 receptors and has a direct inhibitory effect on pituitary prolactin secretion resulting in reduced serum prolactin levels. Methods: A pilot phase II study of cabergoline in patients with metastatic breast cancer was conducted with primary end point of best overall response rate (ORR) among patients with measurable disease. Eligible patients had metastatic breast cancer, any receptors status was allowed, and there was no limit of prior lines of therapy. Both measurable and unmeasurable diseases (RECIST 1.1) were allowed. Cabergoline 1mg orally, twice weekly (1 cycle = 4 weeks) was given until disease progression or unacceptable toxicity. Immunohistochemistry prolactin receptor staining was performed on available baseline tumor tissue, and serum prolactin levels were serially assessed. Results: A total of 20 women were enrolled, 19 of whom were evaluable for response (one patient died on C1D7 of unrelated causes). Mean age was 62 (range 42-83); 15 (75%) were Caucasian; mean number of prior lines of therapy 5 (range 0-14). Tumor receptor statuses were distributed as follows: HR+/HER2+ 1(5%), HR+/HER2- 18 (80%), HR-/HER2+ 1 (5%). Analysis was performed after a median follow-up of 6.8 months (0.2-26.2). Best ORR was 8.3% among 12 patients with measurable disease. Results for secondary endpoints were as follows: 4-month CBR = 26% (including patients with measurable and non-measurable disease), median PFS = 1.9 months, and median OS = 10.4 months. Most common treatment related AEs were nausea (30%), fatigue (25%), and elevation in alkaline phosphatase (15%). The highest-grade AE was a single grade 3 treatment-related pain in extremity. Nine patients had sufficient baseline tissue for analysis, there was no correlation between baseline tumor prolactin receptor expression and clinical benefit ( p= 0.24). Additional correlative work is ongoing. Conclusions: Cabergoline was well tolerated and associated with modest anti-tumor activity. Clinical trial information: NCT01730729.

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