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Biomedical subjects

W E Stumpf

Publications and source records attributed to W E Stumpf.

At least 217 records · Page 12Linked to original sources

3H estradiol in catecholamine neurons of rat brain stem: combined localization by autoradiography and formaldehyde-induced fluorescence.

3H setradion-17beta was localized in nuclei of catecholamine (CA) neurons of the rat lower brain stem, i.e., midbrain, pons and medulla, by employing a combined formaldehyde-induced fluorescence (FIF)-autoradiography approach which permits the direct visualization of 3H estradiol uptake in relation to CA-neuron perikarya and terminals. In the medulla, noradrenalin (NA)-containing neurons in and adjacent to the nucleus (n.) reticularis lateralis (group A1) and in the vicinity of the n. tractus solitarii (group A2) concentrated 3H estradiol. In the pons, NA neurons dorsal to the n. olivaris superior (group A5), in the locus ceruleus (group A6) and ventral to the pedunculus cerebellaris superior (group A7) displayed 3H estradiol uptake. In the midbrain, dopamine (DA)-containing neurons in the n. cuneiformis (group A8), in the zona compacta of the substantia nigra (group A9) and adjacent to the n. interpeduncularis (group A10), were not seen to concentrate 3H estradiol. This is in contrast to DA neurons in the n. arcuatus of the hypothalamus (group A12), previously reported to concentrate 3H estradiol. In addition, certain non-CA-containing neurons with nuclear uptake of 3H estradiol were observed to be surrounded by CA terminals in such areas as substantia grisea centralis, n. tractus solitarii and n. tractus spinalis nervi trigemini. This suggests a second mode of interaction between CA neurons and estrogen target neurons. The estradiol-CA neuron relationships described may provide morphological substrates underlying functional interactions between estradiol and CA neurons in the rat brain.

Animals↗

The collicular recess organ: evidence for structural and secretory specialization of the ventricular lining in the collicular recess.

The collicular recess organ and adjacent portions of the collicular recess were studied by light microscopy, scanning electron microscopy and transmission electron microscopy. In the collicular recess, the ventricular wall contains folds and is well vascularized. The adluminal ependymal cells generally bear kinocilia and microvilli on their ventricular surface. Among the cilia, many secretory droplets, some axons, and few supraependymal cells are seen. Various stages of apocrine ependymosecretion are observed. In addition to tanycytes, coelocytes are found scattered throughout the ependymal lining of the collicular recess. Coelocytes, characterized by lumina containing cilia and a few microvilli, are accumulated in ependymal and hypependymal positions of the collicular recess organ at the roof of the collicular recess.

Animals↗

Autoradiographic studies of 3H-dexamethasone uptake by immunocytochemically characterized cells of the rat pituitary.

3H-Dexamethasone (10 microgram/kg) was injected intravenously in adrenalectomized rats and after survival times of 5, 30, 60, and 180 min its uptake within the pituitary was studied by autoradiography. Radioactivity was concentrated in cell nuclei in the pars nervosa and pars distalis. Within the pars intermedia, only cells of the marginal zone were labeled. In the pars distalis, some cells showed a weak nuclear accumulation of radioactivity as early as 5 min after injection. The tissue radioactivity was nearly maximal at 5 min, and the proportion of radioactivity in nuclei reached a maximum of 60-70% by 30 min. In competition experiments, non-radioactive steroids (1 mg/kg) were injected 5 min before 3H-dexamethasone and sacrifice was 30 min later. Dexamethasone markedly diminished the nuclear accumulation in the pars distalis, but corticosterone and progesterone did not. In the pars nervosa, corticosterone and progesterone competed for nuclear uptake of 3H-dexamethasone, although less effectively than dexamethasone itself. Different cell types in the pars distalis were characterized by treating autoradiograms with an immuno-peroxidase bridge procedure. Cells treated with anti-ACTH 17-39 had the greatest nuclear concentration of radioactivity, and those stained with anti-TSH were least heavily labeled. Cells treated with antisera to GH, PRL, and hCG were moderately labeled.

Adrenalectomy↗

Androgen concentration in motor neurons of cranial nerves and spinal cord.

After injection of [3H]dihydrotestosterone, a major testosterone metabolite, radioactivity is concentrated in nuclei of certain cells in the midbrain, pons, medulla oblongata, cerebellum, and spinal cord. While there is some overlap between androgen and estrogen target neuron distribution, certain motor neurons appear to be selectively labeled by androgen; in contrast, estrogen localization prevails in sensory neurons. These results may help to explain why male sexual behavior in some rodents is not fully activated with dihydrotestosterone alone but in addition requires estradiol, a testosterone metabolite.

Adrenalectomy↗

The heart: a target organ for estradiol.

Autoradiographic studies of rat heart reveal that tritiated estradiol concentrates in cell nuclei of the myocardium of the atria and auricles, similar to the myometrium of the uterus. This suggests that estrogen has a direct effect on atrial myocytes through which its "protective" action may be mediated. Cardiac glycosides that are known to exert estrogen-like effects on classical estrogen target tissues, such as uterine muscle, endometrium, vagina, and mammary gland, probably act on atrial muscle through a genomic, steroid hormone-like mechanism of action.

Animals↗

Steroid hormone target cells in the periventricular brain: relationship to peptide hormone producing cells.

Steroid hormone concentrating cells in hypothalamic and extrahypothalamic regions are reviewed and the topographic relationship to the periventricular brain and the ventricular recess organs is discussed. Steroid hormone target cells in the brain are considered feedback sites and production sites of polypeptide hormones. The anatomical distribution of estrogen, androgen and progestin target neurons, as defined by autoradiography, is compared with the localization of antibodies to luteinizing hormone-releasing hormone and somatostatin in perikarya of neurons, as characterized by immunocytochemistry. Around the optic recess of the third ventricle in the lamina terminalis and the preoptic nucleus as well as in the periventricular nucleus of the hypothalamus, the steroid hormone target neurons and the assumed polypeptide hormone producing neurons occupy corresponding sites.

Amygdala↗

Anatomical distribution of estrogen target cells in the avian CNS: a comparison with the mammalian CNS.

The distribution of labeled cells was investigated in the brain of the ring dove one hour after administration of 3H-estradiol. Major areas of concentration of labeled cells were found in (1) the preoptico-strial region: nucleus preopticus medialis and nucleus interstitialis of the dorsal olfactory projection, (2) the basal hypothalamic region: nucleus hypothalamicus posterior medialis and nucleus inferior, (3) the amygdaloid region: nucleus taeniae and adjacent portions of the archistriatum, and (4) the midbrain: substantia grisea surrounding the nucleus mesencephalicus lateralis, pars dorsalis. The findings support the phylogenetic homologies between the avian nucleus interstitialis of the dorsal olfactory projection and the mammalian nucleus interstitialis of the stria terminalis, the avian nucleus hypothalamicus posterior medialis and the mammalian nucleus ventromedialis hypothalami, as well as the avian nucleus inferior and the mammalian nucleus infundibularis-premammillaris ventralis. The results also suggest that the nucleus medialis and other more differentiated labeled areas of the mammalian amygdala.

Animals↗

Quantitative autoradiographic assessment of 3H-estradiol uptake in immunocytochemically characterized pituitary cells.

Dry-mount autoradiography was combined with peroxidase immunocytochemistry to examine estrogen uptake in four pituitary cell types. Quantification by silver grain counts was used to compare 3H-estradiol uptake in nuclei of pituitary cells 60 min after i.v. injection into short-term (control) and long-term ovariectomized and in long-term thyroidectomized rats. Under all three hormonal states, the order of labeling intensity was: gonadotropes greater than somatotropes greater than lactotrops greater than thyrotropes. Long-term ovariectomy caused a significant increase in estrogen uptake of gonadotropes, somatotropes and lactotropes, while uptake in thyrotropes decreased. Long-term thyroidectomy decreased uptake in somatotropes, lactotropes and thyrotropes while gonadotropes remained unchanged.

Animals↗

Regional differences between nuclear concentration of (3H) estradiol and (3H) progesterone and their action on the uterus of rat during delayed implantation.

The cellular and subcellular localization of radioactivity by dry-mount autoradiography was studied at 5, 15 and 30 minutes after intraluminal or at 5, 15, and 60 minutes after subcutaneous administration of (3H) estradiol or (3H) progesterone to rats in which implantation was delayed by ovariectomy on day 3 post-coitum, followed by treatment with progesterone. After intraluminal instillation of (3H) estradiol or (3H) progesterone, radioactivity was cleared from the uterine lumen at 5 minutes. After intraluminal as well as subcutaneous injection of (3H) estradiol, radioactivity was concentrated at all time intervals in the nuclei of cells of the substantia propria, glands and muscularis, but not in the luminal epithelium. White blood cells and endothelial cells were unlabeled, while perivascular cells showed concentration of radioactivity. After intraluminal instillation of (3H) progesterone, radioactivity was retained in the cytoplasm of the luminal epithelium at 5 and 15 minutes, while no such concentration appeared after subcutaneous injection. No selective nuclear retention was observed in the luminal epithelium, in contrast to the substantia propria and muscularis. The autoradiographic results indicate that progesterone treatment simulating the conditions of early pregnancy, changes the uptake affinity of uterine tissues for (3H) estradiol. The lack of a detectable concentration of estrogen within nuclei of the luminal epithelium does not preclude hormone action. Possible mechanisms of metabolic activation of the uterine luminal epithelium in the apparent absence of concentration of (3H) estradiol to nuclei of the luminal epithelium are discussed.

Animals↗

Estrogen target sites in the brain of the chick embryo.

Autoradiograms prepared from brains of chick embryos after injection of [3H]estradiol demonstrate the existence of target cells for estrogen in the medial preoptic and ventral hypothalamic regions as early as day 10 of incubation. Target cells also appear in telencephalic locations during later stages of embryonic development. These hormone-concentrating cells probably are the anatomical substrate for the formative action of sex steroids during embryonic life on certain brain functions such as control of sexual and aggressive behaviour and gonadotropin secretion.

Age Factors↗

Direct visual input to the limbic system: crossed retinal projections to the nucleus anterodorsalis thalami in the tree shrew.

Evidence for a direct projection from the retina to the nucleus anterodorsalis thalami in the insectivore, Tupaia glis, is presented. 100 muCi tritiated amino acid or amino acid/monosaccharide cocktail were administered as two separate intravitreal injections of 50 muCi each. Fibers were traced using thawmount autoradiography in which tissue is frozen in liquid propane, cryostat-cut, and mounted on photographic emulsion precoated slides (Conrad and Stumpf, 1974). From the dorsolateral geniculate body, contralateral retinal fibers continue as a dorsomedial extension of the optic tract. When traced rostrally from this point, the fibers form a thin fascicle coursing medially under the third ventricle. In the anterior thalamus the bundle arborizes within the n. anterodorsalis, infiltrating its caudal pole completely but only encapsulating the nucleus anteriorly. This new retino-anterodorsal thalamic projection, together with the known anterior thalamic-retrosplenial projection, represents a third visual pathway in Tupaia glis distinct from the retino-geniculo-striatal and retino-tecto-pulvinar-peristriatal systems. It is significant that each of these thalamic relay nuclei projects to an architectonically different cortical region, with the nucleus anterodorsalis sending afferents to the phylogenetically most primitive of the visual cortices, the retrosplenial proisocortex or prostriata (Vitzthum and Sanides, 1967). It is proposed that the retino-anterior thalamic-retrosplenial circuit forms an anatomical substrate by which light cues may affect emotional behavior and corresponding neurovisceral responses.

Amino Acids↗

Atlas of estrogen-concentrating cells in the central nervous system of the squirrel monkey.

Estrogen is concentrated within cellular nuclei in discrete regions of the monkey brain 30 and 60 minutes following intravenous injection of [3H] estradiol. Chromatographic data is provided to suggest that most of the localized estrogen is in the form of estradiol with lesser amounts of estrone and estriol. Three "major" areas of estrogen accumulation include: (1) preopticostrial accumulation: n. preopticus medialis--n. interstitialis striae terminalis, (2) basal hypothalamic accumulation: n. infundibularis--n. ventromedialis--n. premammillaris ventralis, and (3) the amygdaloid accumulation. Several "minor" areas of estrogen accumulation include the tuberculum olfactorium, insulae Calleja, n. triangularis septi, a. hypothalamica anterior, n. anterior hypothalami, n. paraventricularis, n. supraopticus, n. periventricularis and the substantia grisea centralis. The neocortex, rhombencephalon and spinal cord are essentially unlabeled. The major areas of accumulation are similar in several other mammalian and avian species while these, and some minor areas of accumulation, have been shown in neuroanatomical studies to be interconnected by several pathways, especially the stria terminalis. Lesion, implant, stimulation, recording and morphometric studies, in several species, support the concept that this arrangement provides a neuroanatomical substrate which would allow the integration of the various facets of the neuroendocrine reproductive response.

Amygdala↗

Simultaneous autoradiographic and immunohistochemical localization of estrogen and gonadotropin in the rat pituitary.

A combined autoradiographic and immunohistochemical technique is introduced which is suitable to simultaneously localize hypophyseal sites of nuclear (3-H)-estradiol uptake and anti-hCG-characterized "gonadotropes". Most, but not all, "gonadotropes" show significant nuclear concentration of radioactivity. A large percentage of non-"gonadotropes" also show nuclear uptake of label.

Animals↗