Expression of aromatase and 17beta-hydroxysteroid dehydrogenase types 1, 7 and 12 in breast cancer. An immunocytochemical study.

It is known that there is a local biosynthesis of estradiol (E2) in breast carcinoma. The steroidogenic enzymes involved in E2 formation are aromatase which transforms testosterone into E2 and androstenedione into estrone (E1) and reductive 17beta-hydroxysteroid dehydrogenases (17beta-HSDs) which convert E1 into E2. Using immunocytochemistry, we have studied the expression of aromatase and the three reductive 17beta-HSDs 17beta-HSD types 1, 7 and 12 in 41 specimens of female human breast carcinoma and adjacent non-malignant tissues.

Increased brain content of the endogenous benzodiazepine receptor ligand, octadecaneuropeptide (ODN), following portacaval anastomosis in the rat.

Evidence suggests that endogenous benzodiazepine receptor ligands such as diazepam binding inhibitor (DBI) and its metabolite octadecaneuropeptide (ODN) may be implicated in the pathogenesis of hepatic encephalopathy. Using an immunocytochemical technique and an antibody of high specific activity to synthetic ODN, we studied the effects of portacaval anastomosis (PCA) on ODN distribution in rat brain. Four weeks after PCA, ODN immunolabeling was increased in several brain regions including cerebral cortex, hippocampus, hypothalamus and thalamus.

Localization of the endogenous benzodiazepine ligand octadecaneuropeptide in the rat testis.

Diazepam binding inhibitor (DBI) is the precursor of a family of peptides, including an octadecaneuropeptide (ODN), which share with DBI the ability to specifically displace benzodiazepines (BZD) from their receptors. BZD receptors have been found not only in the brain, but also in a variety of peripheral tissues, including the testis. To clarify the role of ODN in the testis, we have investigated the localization of ODN in the rat testis using two different cytochemical approaches: immunocytochemistry and in situ hybridization.

Localization of the endogenous benzodiazepine receptor ligand octadecaneuropeptide and peripheral type benzodiazepine receptors in the rat pituitary.

Abstract An association of octadecaneuropeptide, an endogenous ligand at the benzodiazepine receptor, with the peripheral type benzodiazepine receptor has been reported in brain as well as a few peripheral tissues. In order to verify whether or not such an association occurs in the rat pituitary gland, we have proceeded to the immunocytochemical localization of octadecaneuropeptide as well as the autoradiographic localization of peripheral type benzodiazepine receptors in rat pituitary, octadecaneuropeptide immunoreactive material was found in high concentrations in the posterior lobe, whereas only a very few cells were labelled in the intermediate lobe. The anterior lobe did not show any specific staining.

Immunocytochemical localization of the endogenous benzodiazepine ligand octadecaneuropeptide (ODN) in the rat brain.

In order to study the morphological localization of the endogenous benzodiazepine ligand octadecaneuropeptide (ODN) in rat brain, we have developed antibodies against this peptide. Using a radioimmunoassay for ODN, we have observed that synthetic ODN and serial dilutions of several brain areas gave parallel displacement curves. By light microscope immunocytochemistry, ODN-immunoreactive material was only detected in glial and ependymal cells.

Melanin-concentrating hormone (MCH) is colocalized with alpha-melanocyte-stimulating hormone (alpha-MSH) in the rat but not in the human hypothalamus.

Melanin-concentrating hormone (MCH)-containing neurons have recently been localized in the dorsolateral region of the rat hypothalamus, an area where the second alpha-MSH system is found which contains only alpha-MSH and none of the pro-opiomelanocortin (POMC)-related peptides. In order to study the morphological relationships between the MCH and alpha-MSH neuronal systems, we have studied the immunocytochemical localization of both MCH and alpha-MSH in the rat hypothalamus. The same study was also performed in the human hypothalamus where there is only one alpha-MSH system which contains alpha-MSH as well as the other POMC-related peptides (first alpha-MSH system).

Light-microscopic immunocytochemical localization of growth hormone-releasing factor in the human hypothalamus.

The distribution of growth hormone-releasing factor (GRF)-like immunoreactivity in the human hypothalamus was studied by light-microscopic immunocytochemistry. With antibodies that we developed against synthetic human pancreatic GRF (hpGRF), we localized GRF immunoreactivity in neuronal cell bodies that were observed only in the infundibular (arcuate) nucleus. Immunostained nerve fibers were found in large numbers in the neurovascular zone of the median eminence, in the proximal portion of the pituitary stalk and in periventricular areas.

Immunocytochemical localization of neuropeptide Y (NPY) in the human hypothalamus.

In order to study the distribution of neuropeptide Y-like immunoreactivity in the human hypothalamus, an immunocytochemical localization of this peptide was performed. Using antibodies developed against synthetic porcine neuropeptide Y (NPY), we have been able to localize immunoreactivity in neuronal cell bodies located exclusively in the infundibular nucleus. Immunostained fibers were found in several regions in the hypothalamus with a high concentration in the periventricular areas.

Immunocytochemical localization of corticotropin-releasing factor-like immunoreactivity in the human hypothalamus.

In order to study the distribution of corticotropin-releasing factor-like immunoreactivity (CRF-LI) in the human hypothalamus, an immunocytochemical localization of this neurohormone was performed. Using antibodies developed against ovine CRF, we have localized CRF-LI in parvicellular neuronal cell bodies in the paraventricular nucleus. Immunostained fibers were observed in the median eminence, the pituitary stalk and the posterior pituitary.

Localization of ACTH in the human hypothalamus.

Using an antiserum to porcine ACTH and the unlabeled antibody preoxidase-antiperoxidase technique, we have found that ACTH is present in neuronal cell bodies located exclusively in the arcuate nucleus of the human hypothalamus. ACTH-containing fibers are distributed extensively throughout the hypothalamus with a greatest density in the periventricular nucleus. No concentration of ACTH fibers could be observed in the neurovascular zone of the pituitary stalk.

Inhibition of spermatogenesis in the rat by treatment with [D-Ala6, Des-Gly-NH210] LHRH ethylamide.

The effect of treatment with a potent LHRH agonist, [D-Ala6, Des-Gly-NH210]LHRH ethylamide, injected at the low dose of 100 ng, twice a week, was evaluated on spermatogenesis in the rat. Significant degenerative changes of seminiferous tubules could be observed after two weeks of treatment. These changes were progressive and led to a marked inhibition of spermatogenesis after four to eight weeks of treatment.

Immunohistochemical localization of somatostatin in the human hypothalamus.

In order to identify clearly the nervous structures containing somatostatin in the human hypothalamus, an immunohistochemical localization of this neurohormone was performed at light-microscopic level. Using a antiserum specific to somatostatin and the unlabeled antibody peroxidase-antiperoxidase technique, we have found somatostatin in neurons with cell bodies in an area in the anterior hypothalamus corresponding to the infundibular nucleus. Somatostatin-containing fibers were also detected in the neurovascular zone of the pituitary stalk, suggesting that somatostatin is released in that region to reach the capillaries in the pituitary portal plexus.