GnRH receptors in human breast cancer and its contiguous not-involved breast tissue.

The present study was undertaken to evaluate the presence of GnRH receptors (GnRH-R) in breast cancer and not-involved breast tissue, and the relationships between GnRH-R and receptors for estrogen (ER) and progesterone (PgR) in the same tissues. Utilizing a tritiated natural GnRH in order to assay the native receptor binding we analyzed the level of binding sites for GnRH in membranes derived from 90 breast tumors and in 40 cases from neighboring, not-involved breast tissue. GnRH-R was found both in cancer and normal tissues. The prevalence for GnRH-R was higher in tumor than in not-tumor tissue (45% vs 39%, respectively), but the overall levels were not significantly different (15.9+/-24 fmol/mg protein vs 18.2+/-39 fmol/mg protein, respectively). The only statistically different content of GnRH-R we found concerned PgR negative vs PgR positive tumor tissues (mean content: 23 vs 11 fmol/mg protein, respectively in PgR- and PgR+ tumors, p=0.03 by t test); furthermore the proportion of GnRH-R positive cases in the tumor resulted significantly higher in premenopausal patients vs postmenopausal (56% vs 32%, by Chi square test, p<0.05). The GnRH receptors status of primary tumor and contiguous not-involved breast tissue resulted associated (overall agreement: 63%, p<0.05) but no specific steroid patterns for GnRH-R positivity was observed.

Gonadotrophin releasing hormone (GnRH) receptor and steroid receptors in human uterine leiomyoma, myometrium and endometrium.

The present study evaluated the presence of GnRH-R in leiomyomas, in associated, non-involved uterine tissues (myometrium and endometrium) and the possible relationships between GnRH-R and the receptors for estrogen and progesterone in the same tissues. GnRH-R was found in all uterine tissues and both GnRH and the GnRH analog, goserelin, displaced its binding consistent with a single type of high affinity receptor (Kd approximate to 10(-8) M). GnRH-R were found more frequently in myometrium (81% of samples) than in endometrium (58%) or leiomyoma (42%). However, the mean receptor content was lowest in myometrium (139+/-19 fmol/mg protein) with both leiomyomas (288+/-77 fmol/mg protein) and endometrium (372+/-96 fmol/mg protein) having significantly higher values. Endometrial GnRH binding varied from 596+/-42 in uteri that were GnRH-R positive in the endothelium alone to 231+/-49 when GnRH-R was present also in the other tissues. Endometrium negative for the GnRH-R had significantly higher levels of estrogen receptor than all the other uterine samples (266+/-25 vs 61+/-7.5 fmol/mg protein, respectively). Endometrial GnRH-R seem to be dependent on its presence and/or level in other uterine tissues. Further, when GnRH-R is absent in the endometrium this tissue expresses greatly increased levels of steroid receptors.

Characterization of a h-3 GnRH method for the measurement of GnRH binding-sites in human breast-cancer and breast-cancer cell-lines.

The peptide hormone, GnRH has been hypothesized to play a direct antitumoral role in certain kinds of breast cancer. This direct effect is considered to function via high affinity membrane receptors to GnRH that have been demonstrated in tumors. However, no routine assay for GnRH receptors exist limiting further research in elucidating the mechanisms of GnRH action during treatment and both the clinical usefulness of this measure and the development or refinement of GnRH treatments. Part of the problem has been that previously reported procedures require expensive, difficult (for routine clinical laboratories) iodination of specific GnRH analogs. The use of iodinated substrates present the additional problems of radioactive waste disposal and safety of laboratory personal. Further, the use of different analogs complicates the comparison of data between laboratories. We present an assay that utilizes tritiated natural GnRH in order to assay the native receptor binding and reduce both safety problems and cost of assay/waste disposal. The use of nitrocellulose filters treated overnight with 1% BSA resolved the problems of high blank values. Kinetic data demonstrate that this assay is sensitive, accurate and give results comparable with other methods. We also show that the membranes derived from the tumor and the cell cultures may be frozen at -80 degrees C for up to 90 days without affecting the results of the assay.

Effect of caerulein on pituitary response to TRH in humans.

The effect of caerulein (100 ng/kg/h X 1 h) on basal as well as on thyrotropin-releasing hormone (TRH)-stimulated prolactin and thyroid-stimulating hormone (TSH) secretion was studied in healthy male volunteers. The peptide did not change the basal levels of prolactin and TSH. However, during the infusion of caerulein, prolactin response to TRH was significantly increased whereas the TSH response was decreased. These data, showing an action of caerulein (a frog peptide which mimics the biological actions of cholecystokinin) on prolactin and TSH release, suggest that cholecystokinin may be involved in the physiological control of human pituitary secretion.

The validity of the urocytogram compared to colpocytology in hormonal cytodiagnosis.

The AA. studied the degree of significance in results obtained from a parallel urocytologic and colpocytologic study in sixty-two regularly menstruated women. The analysis of the data showed a significant correspondence between the results of both procedures regarding the karyopyknotic index, although the curve obtained by urocytogram was constantly lower than that one by colpocytology. From the study it emerges clearly the validity of urinary cytology for hormonal evaluation as alternative to colpocytology where the evaluation is often negatively influenced by many local factors.