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Biomedical subjects

W E Stumpf

Publications and source records attributed to W E Stumpf.

At least 199 records · Page 11Linked to original sources
PubMed1980

Cellular and subcellular localization of 1,25-(OH)2-vitamin D3 in rat kidney: comparison with localization of parathyroid hormone and estradiol.

Results of thaw-mount autoradiographic studies of kidney obtained 1--3 hr after a single injection of 1,25-(OH)2-[3H]vitamin D3 to rats showed strong nuclear concentration of radioactivity in podocytes and cells of distal tubules, including the pars convoluta, macula densa, and pars recta. Intermediate nuclear concentration was found in cells of the thin limb of Henle's loops, whereas weak or no nuclear uptake was seen in cells of the proximal tubules. In contrast, after injection of 3H-labeled parathyroid hormone or [3H]estradiol, mainly cells of the proximal tubules were labeled; after 3H-labeled parathyroid hormone, apical cytoplasmic uptake of radioactivity was seen most strongly in the proximal part of the proximal tubules, whereas, after [3H]estradiol, weak nuclear concentration was seen in cells throughout the proximal tubules. The results are consistent with the concept that synthesis of 1,25-(OH)2-vitamin D3 occurs in the proximal tubules under stimulation of parathyroid hormone or estradiol (or other hormones) and that the major site of action of 1,25-(OH)2-vitamin D3 is in the distal tubules.

Animals↗
PubMed1980

Estrogen target cells in the larynx: autoradiographic studies with 3H-diethylstilbestrol in fetal mice.

Serial sections from 16-day mouse embryos from mothers injected with 3H-diethylstilbestrol were processed for autoradiography. The distribution, in the laryngeal region, of cells with nuclear concentrations of radioactivity was analyzed. Estrogen receptor cells were found in the mesenchyme of the vocal cords and lateral to the laryngeal aditus. The embryological and oncological implications of these findings are discussed.

Animals↗
PubMed1980

Immunocharacteristics of oestrogen and androgen target cells in the anterior pituitary gland of the chick embryo as demonstrated by a combined method of autoradiography and immunohistochemistry.

The distribution of oestrogen and androgen target cells in the anterior pituitary gland of the chick embryo on days 10, 12 and 15 of incubation was studied 1 h after the injection of tritium-labelled steroid hormone using the thaw-mount autoradiographic technique. Oestradiol target cells were localized in the caudal zone that corresponds to the so-called 'caudal lobe', while androgen target cells were found throughout the rostral and caudal lobes of the anterior pituitary gland. With a combined autoradiography and immunohistochemistry technique, most of the oestrogen target cells showed immunoreactivity to turkey LH antiserum but not to adrenocorticotrophin (1-24) and beta-thyrotrophin antisera. In contrast, androgen target cells did not show positive immunoreactivity to the three antisera used. The results suggested a direct and early involvement of oestrogens but not of androgens in the feedback regulation of pituitary gonadotrophin secretion in the chick embryo.

Androgens↗
PubMed1979

Target cells for 1,25-dihydroxyvitamin D3 in intestinal tract, stomach, kidney, skin, pituitary, and parathyroid.

After mature rats that had been fed on a vitamin D3-deficient diet were injected with tritium-labeled 1,25-dihydroxyvitamin D3, radioactivity became concentrated in nuclei of luminal and cryptal epithelium of the duodenum, jejunum, ileum, and colon; in nuclei of the epithelium of kidney distal tubules including the macula densa, and in podocytes of glomeruli; in nuclei of the epidermis including outer hairshafts and sebaceous glands; and in nuclei of certain cells of the stomach, anterior and posterior pituitary, and parathyroid. These results reveal cell types that contain receptors for 1,25-dihydroxyvitamin D3 or metabolites of this compound both in known or hypothesized target tissues and in tissues that were previously unknown to participate in vitamin D3 metabolism.

Animals↗
PubMed1979

Nuclear localization of aldosterone in rat brain cells assessed by autoradiography.

Autoradiographic studies with 3H aldosterone demonstrate nuclear concentration of hormone in neurons of the hippocampus, septum, allocortical regions and brain stem reticular formation and motor nuclei of cranial nerves and in the meninges. The results suggest that mineralocorticoids have wide ranging effects on different parts of the central nervous system.

Adrenalectomy↗
PubMed1979

Topographical distribution of estrogen target cells in the forebrain of platyfish, Xiphophorus maculatus, studied by autoradiography.

In the platyfish, Xiphophorus maculatus, after injection of [3H]estradiol-17 beta, nuclear concentration of radioactivity is observed in certain cells of the forebrain. These labeled cells are accumulated in periventricular midline regions that include in the telencephalon the ventral precommissural and dorsal supracommissural areas, and in the diencephalon the preoptic, central hypothalamic and thalamic areas. The specialized ependyma of the subcommissural organ also shows nuclear concentration of radioactivity, while other ependymal cells remain unlabeled. Similar to other vertebrate classes, the accumulations of estrogen target cells exist characteristically in the vicinity of the ventricular system, especially its recesses. This implies close topographical relationships between estrogen target cells and the ventricular recess organs, including the optic recess organ, the infundibular recess organ, the paraventricular organ and the subcommissural organ. Different from other vertebrate classes, no pallial accumulations of estrogen target cells are seen in the teleost.

Animals↗
PubMed1979

Estrogen target cells in the pituitary of platyfish, Xiphophorus maculatus.

The distribution of estradiol-concentrating cells in the pituitary of the platyfish, Xiphophorus maculatus, is studied after the injection of 3H estradiol-17 beta by thaw-mount autoradiography. Autoradiograms prepared 2-8 h after the injection show nuclear concentration of radioactivity in certain cells of the rostral pars distalis, pars intermedia and pars nervosa. Radioactively labeled cells are identified as gonadotropes by a combined technique of thaw-mount autoradiography and immunoperoxidase staining with antiserum to ovine LH. Approximately 80% of the immunoreactive LH cells show a concentration of radioactivity in their nuclei. These observations indicate that in teleosts, as in mammals, estradiol has a direct effect on pituitary gonadotropes.

Animals↗
PubMed1979

Simultaneous localization of steroid and peptide hormones in rat pituitary by combined thaw-mount autoradiography and immunohistochemistry: localization of dihydrotestosterone in gonadotropes, thyrotropes and pituicytes.

The immunocharacteristics of androgen target cells in the anterior pituitary of male rats are assessed by a combined thaw-mount autoradiography and immunoperoxidase staining method permitting the simultaneous identification of steroid-hormone target cells and protein or polypeptide hormone-producing cells in the same preparation. After injection of 3H-dihydrotestosterone, nuclear concentration of radioactivity is observed in cells of the anterior lobe, in "ectopic" cells in the intermediate and posterior lobes as well as in certain pituicytes. The radioactively labeled cells in the anterior lobe are identified immuno-histochemically as gonadotropes and thyrotropes with the use of antiserum to ovine LH or its subunit beta-LH and bovine beta-TSH. The results suggest genomic effects of androgen on gonadotropes and thyrotropes as well as pituicytes.

Animals↗
PubMed1979

Relationships between the catecholaminergic and enkephalinergic systems demonstrated by a combined technique of formaldehyde-induced fluorescence and immunocytochemistry.

A technique for the localization of catecholamines and enkephalin in the same tissue section is described. Sections from rat brains prepared according to the Falck-Hillarp technique were examined by dark field fluorescence microscopy and then processed for immunocytochemistry for leucine-enkephalin (leu-enk) using the unlabeled antibody technique. In the medial hypothalamus the distribution of the catecholamines and enkephalin is complementary, while in the lateral hypothalamus the patterns are similar but not identical. Enkephalin terminals are also observed in and around the locus coeruleus, while enkephalin cell bodies are adjacent to the nucleus.

Animals↗
PubMed1978

Topography of estrogen target cells in the forebrain of goldfish, Carassius auratus.

The topographical distribution of estradiol-concentrating cells in the brain of male and female teleost, Carassius auratus, was determined by autoradiography, after injection of 3H estradiol-17beta. Radioactively labeled neurons are found in specific regions of the forebrain, with a similar topographical distribution both in males and females. Regions of accumulation of estrogen target cells include the supracommissural area of the telencephalon, the preoptic area, the central hypothalamic area and the thalamic area. Unlabeled estradiol injected prior to the administration of 3H estradiol reduces or eliminates nuclear uptake of radioactivity. The autoradiographic results demonstrate the existence of estrogen target neurons in the teleost forebrain at sites similar to those described in mammalian brains. However, under the conditions of the experiment, there exists no pallial representation of estrogen target cells.

Animals↗
PubMed1978

Immunohistochemical localization of enkephalin in rat brain and spinal cord.

The distribution of immunoreactive enkephalin in rat brain and spinal cord was studied by immunoperoxidase staining using antiserum to leucine-enkephalin ([Leu5]-enkephalin) or methionine-enkephalin ([Met5]-enkephalin). Immunoreactive staining for both enkephalins was similarly observed in nerve fibers, terminals and cell bodies in many regions of the central nervous system. Staining of perikarya was detected in hypophysectomized rats or colchicine pretreated rats. The regions of localization for enkephalin fibers and terminals include in the forebrain: lateral septum, central nucleus of the amygdala, area CA2 of the hippocampus, certain regions of the cortex, corpus striatum, bed nucleus of the stria terminalis, hypothalamus including median eminence, thalamus and subthalamus; in the midbrain: nucleus interpeduncularis, periaqueductal gray and reticular formation; in the hind brain: nucleus parabrachialis, locus ceruleus, nuclei raphes, nucleus cochlearis, nucleus tractus solitarii, nucleus spinalis nervi trigemini, motor nuclei of certain cranial nerves, nucleus commissuralis and formatio reticularis; and in the spinal cord the substantia gelatinosa. In contrast enkephalin cell bodies appear sparsely distributed in the telencephalon, diencephalon, mesencephalon and rhombencephalon. The results of the histochemical staining show that certain structures which positively stain for enkephalin closely correspond to the distribution of opiate receptors in the brain and thus support the concept that the endogenous opiate peptides are involved in the perception of pain and analgesia. The localization of enkephalin in the preoptic-hypothalamic region together with the presence of enkephalin perikarya in the paraventricular and supraoptic nuclei suggest a role of enkephalin in the regulation of neuroendocrine functions.

Animals↗
PubMed1978

Estrogen target sites in the cloacal region of female and male chick embryos.

After intravenous injection of 3H-estradiol in the 12-day old chick embryo, radioactivity is concentrated in nuclei of certain cells in the cloacal area. The nuclear labeling is observed in mesenchymal cells along the different portions of the cloaca, and in an unidentified tissue located laterally to the cloaca. The labeled mesenchymal cells display a definite pattern of distribution along the epithelial wall of the cloaca, identical both in male and in female embryos. In the adjacent bursa of Fabricius, cells do not concentrate labeled hormone in their nuclei. The presence of estrogen receptors in the cloacal area of embryos of either sex adds evidence, at the cellular level, to support the concept of a "neutral", or undifferentiated, sex with estradiol inhibiting this "neutral" male differentiation.

Animals↗
PubMed1978

Estrogen localization in the brain of the lizard, Anolis carolinensis (1).

Estrogen induces reproductive behavior in lizards by acting on specific areas of the brain. Neural areas that selectively concentrate radioactivity after 3-h-estradiol administration were mapped using thawmount autoradiography. Major accumulations of hormone-concentrating cells occur in the medial preoptic area, basal hypothalamus, amygdala (n. vetromedialis telencephali) and in and around the torus semicircularis. Numerous smaller accumulations are also described and the topographical distribution is compared with that of avian and mammalian species.

Animals↗
PubMed1978

Bipotentiality of response to sex hormones by the prostate of castrated or hypophysectomized dogs. Direct effects of estrogen.

Prostatic response to administered estradiol-17beta 17-cyclopentylpropionate (ECP) was studied in castrated or hypophysectomized dogs. Ultrastructural investigation identified two types of epithelial cells, squamous and modified glandular, that resulted from estrogen action. Squamous cells, which predominated, appeared to evolve from basal reserve cells. Estrogen-modified glandular cells have features attributable to estrogen and previous androgen stimulation. Thaw-mount autoradiography of explants located radiolabeled estrogen in prostatic epithelium and stroma of normal and ECP-treated animals, suggesting a role of estrogen in prostatic homeostasis. Epithelium from ECP-treated dogs incorporated 3H-thymidine, indicating that estrogen promotes DNA synthesis in these cells. Greatly enhanced conversion of radiotestosterone to 4-androstene-3,17-dione, with sharply decreased formation of 5alpha-reduced hydroxylation products, and attendant elevation in estradiol-17beta oxidoreductase activity are metabolic markers attributable to the induced squamous and responding stromal cells. The duality of prostatic response to sex hormones is apparent from observations that estrogen stimulates regressed glandular epithelium which had undergone androgen-mediated differentiation before ablation.

Animals↗