Biomedical subjects

W E Stumpf

Publications and source records attributed to W E Stumpf.

At least 127 records · Page 7Linked to original sources

PubMed1986

Combined technique of immunohistochemistry and autoradiography for the simultaneous detection of steroid hormone receptors and their ligand.

A combined technique of immunohistochemistry and autoradiography was applied to detect progesterone target cells in tissue sections. The radioactively labeled progestin [3H]-Organon 2058 and the progesterone receptor, revealed by antibodies to the receptor molecule, were localized simultaneously in identical cells on the same tissue section. Technical details that make possible combined detection of the nuclear antigen, present in very small amounts, simultaneously with its steroid ligand are described.

Animals↗

PubMed1986

Nuclear localization of progesterone receptor before and after exposure to progestin at low and high temperatures: autoradiographic and immunohistochemical studies of chick oviduct.

The intracellular location of progesterone receptor and tritiated progestin was assessed in chick oviduct before and after in vitro exposure to 5 nM [3H]Org 2058 ([6,7-3H]16 alpha-ethyl-21-hydroxy-19-nor-4-pregnene-3,20-dione) for 5 or 45 min at 4 or 37 C. The experiments were designed to allow the intracellular localization of occupied and unoccupied receptor in relatively intact tissue. Autoradiography and immunohistochemistry were used to localize [3H]Org 2058 and the progesterone receptor, respectively. Autoradiograms showed radiolabeled progestin concentrated in oviduct cell nuclei not only after incubation at 37 C, but after incubation at 4 C as well. Cytoplasmic concentration was never observed. Immunostaining revealed progesterone receptor always located in cell nuclei, regardless of temperature or time of exposure to labeled ligand or whether the tissue was exposed to progestin. The results indicate that the chick oviduct nuclear progesterone receptor does not undergo a temperature-dependent translocation from cytoplasm to nucleus upon binding ligand.

Animals↗

PubMed1986

Effects of antidepressant drugs injected into the amygdala on behavioral responses of rats in the forced swim test.

Experiments were conducted to determine if the actions of antidepressant drugs in a pharmacological screen would be localized to specific brain regions. Rats were infused in discrete brain regions with drugs of different pharmacological properties and processed in the forced swim test. Infusion of imipramine and pargyline into the amygdala produced behavioral responses similar to i.p. injections of the drugs. The regions of the amygdala from which positive responses could be elicited were highly selective. From cannula placements and diffusion studies with autoradiography it appears that a locus of action of imipramine and pargyline is confined to the central, basolateral and/or lateral nuclear regions of the amygdala. Behavioral responses of rats in which imipramine was infused into the anterior amygdala or caudate-putamen did not differ from saline controls. When infused into regions of the amygdala in which imipramine was active, iprindole, an "atypical" antidepressant, did not produce a behavioral response in the forced swim test. Two "false positives" in the forced swim test, atropine and amphetamine, were also not active when infused into the amygdala. These results indicate that the amygdala is a critical site of action for certain antidepressant drugs in the forced swim test, and that behavioral activation in the test induced by iprindole, amphetamine and atropine involve brain regions other than the amygdala.

Amygdala↗

PubMed1985

Autoradiographic determination of catechol estrogen binding sites in brain, pituitary and uterus.

The anatomical pattern of nuclear binding of 2-OH[6,9-3H]estradiol ([3H]2-OHE2) in brain, pituitary and uterus have been studied autoradiographically. Autoradiograms of forebrain, pituitary and uterus show nuclear concentrations of radioactivity in certain cells. This nuclear concentration is abolished when unlabelled 2-OHE2 or E2 was injected prior to the injection of [3H]2-OHE2. In the brain nuclear labelling is observed in the septal-preoptic region, in the anterior hypothalamic area, and in the central hypothalamic area. Some estrogen-sensitive nuclear groups, such as lateral septum and hippocampus, do not show accumulation of radioactivity. In the uterus, luminal and glandular epithelium, stromal cells and muscle cells are labelled. A comparison of the quantitative nuclear uptake of radioactivity and of the different time intervals after the injection of different doses shows similar uptake of nuclear radioactivity. This is comparable to data obtained after [6,7-3H]estradiol ([3H]E2) injection. The results provide clear evidence for nuclear binding of catechol estrogens of the same magnitude as [3H]E2 after in vivo treatment.

Animals↗

PubMed1985

Ultrastructural characterization of gonadotropin-releasing hormone (GnRH)-producing neurons.

By means of preembedding immunohistochemistry, two types of gonadotropin-releasing hormone (GnRH) positive neurons in the rat could be identified and characterized in the preoptic region and in the diagonal band: (1) a "smooth" GnRH neuron with relatively even cytoplasmic contours, and (2) a "spiny" GnRH neuron with thorn-like protrusions of the perikaryon and cell processes. Both cell types contain the same organelles in similar number and distribution, but they differ in the number of synaptic contacts. In general, GnRH cell bodies have a large round or ovoid nucleus, well-developed rough endoplasmic reticulum arranged in multilayered stacks or as individual cisternae, and several Golgi complexes. Lysosomes are not numerous under the conditions studied. Specializations include kinocilia, nematosomes, and lamellar whorls. Throughout the cytoplasm, scattered dense core vesicles with a diameter of 100 nm and clear vesicles with a diameter of 30-40 nm can be seen with a preferential localization close to the cell membrane. The cell processes of smooth GnRH cells close to the perikaryal appear as extensions of the perikaryal cytoplasm with all organelles except the nucleus. The two neurites originate from the perikaryon as tapering cones over a distance of 200-300 micron, until they reach a diameter of 0.5-3 micron. Cell processes of spiny GnRH cells show bifurcations, protrusions, or invaginations and contain clear and dense core vesicles in their spines. In areas distant from the perikaryon, immunoreactive fibers with a large number of dense core and clear vesicles can occasionally be seen to terminate synaptically or asynaptically on other neurons. The GnRH neurons show postsynaptic specializations at the level of the perikaryon and at cell processes, when apposed by a presynaptic terminal. Such synaptic contacts are seen less frequently on smooth cells than on spiny cells. Large areas of the GnRH cell may be covered by a thin glial lamella, which separates the cell body from the surrounding neuropil. The results indicate the existence of two populations of GnRH cell bodies with different patterns of innervation, which suggest different integrative capacities.

Animals↗

PubMed1985

1,25-Dihydroxyvitamin D3 in teeth of rats and humans: receptors and nuclear localization.

Autoradiographic and biochemical studies were used to demonstrate 1,25 (OH)2 vitamin D3 target cells in teeth. Incisor pulp of rats and molar pulp of humans were incubated in vitro with 3H-1,25 (OH)2 vitamin D3. Subsequent frozen-section autoradiography revealed a large population of cells in the pulp of both incisors and molars which selectively concentrated radioactivity in their nuclei. Extracts of incisor pulp from mature rats were found to bind 3H-1,25 (OH)2 vitamin D3 and this binding was displaceable with excess 1,25 (OH)2 vitamin D3. Sucrose density analysis revealed that the protein in tooth pulp which binds 1,25 (OH)2 vitamin D3 sediments at 3.2-3.5S. The 1,25 (OH)2 vitamin D3 receptor of intestine and kidney also sediments in this region, indicating that the 1,25 (OH)2 vitamin D3 binding protein of tooth pulp is similar to that found in other target organs. These autoradiographic and biochemical data indicate that pulpal cells of mature rat and human teeth contain receptors for 1,25 (OH)2 vitamin D3.

Adult↗

PubMed1985

Nuclear uptake of 1,25-dihydroxyvitamin D3 in developing rodent teeth: an autoradiographic study.

Target cells for 1,25(OH)2 vitamin D3 metabolites are identified in developing rodent teeth by the use of thaw-mount autoradiography. Following the injection of [26, 27-3H]-1,25(OH)2 vitamin D3 into 18-day- and 20-day-old fetal rats and neonatal mice, nuclear concentration of radioactivity is found in different cell types. In incisors of both animal groups, strong nuclear labeling is present predominantly in pulp cells, while relatively weakly labeled cells are found in the layers of odontoblasts, ameloblasts, and stratum intermedium. In molars, nuclear labeling is absent in fetal rats, but is present in 2-day-old neonates in pulp cells and cells in the layers of stratum intermedium of the first molars, but not in the second molars. The absence of labeled pulp cells in the progenitor regions of incisors and in molars of 20-day-old fetal rats, and differential ontogenic appearance of labeled pulp cells in molars, indicates that there is a critical period of receptor emergence. The finding that labeled pulp cells exist in the regions of incisors and molars where secretory odontoblasts are present suggests that nuclear uptake of 1,25(OH)2 vitamin D3 is related to cell maturation and differentiation, and topographically related to the formation of dentin. The results further suggest that, in contrast to bone, the predominant effect of 1,25(OH)2 vitamin D3 is not on tooth cells which are directly involved in the formation of calcified tissue, i.e., ameloblasts and odontoblasts, but rather on supporting tissues such as pulp cells and stratum intermedium.

Animals↗

PubMed1985

Evidence for an association between calmodulin and membrane patches containing gonadotropin-releasing hormone--receptor complexes in cultured gonadotropes.

participation of calmodulin, clathrin, and actin in receptor mediated endocytosis of gonadotropin-releasing hormone (GnRH) was studied in an in vitro system of dispersed pituitary cells with a triple staining procedure. Cells were incubated in D-Lys6-Pro9-Des10-GnRH-biotin and stained with avidin-peroxidase-diaminobenzidine. Calmodulin, clathrin, and actin as well as luteinizing hormone were identified by indirect immunofluorescence with FITC- and rhodamine-labeled second antibody. The results indicate a close spatial association of calmodulin, but not of clathrin and actin, with GnRH-containing plasma membrane patches.

Actins↗

PubMed1985

Differential distribution of 3H dihydrotestosterone and 3H estradiol nuclear binding sites in mouse male accessory sex organs. An autoradiographic study.

The distribution of specific nuclear binding sites for androgens and estrogens in the male accessory sex organs of the mouse was assessed by autoradiography with 3H dihydrotestosterone (3H DHT) and 3H estradiol (3H E2). With 3H DHT nuclear labeling differed among the epithelia of the organs. It was high in seminal vesicle and ampullary gland, moderate in ventral prostate, urethral gland, prostatic excretory ducts and the ampulla ductus deferentis, low in dorsal prostate and low or absent in coagulation gland. With 3H E2, in contrast, epithelial nuclear labeling was high only in coagulation gland, moderate or low in seminal vesicle, low or absent in ventral and dorsal prostate and absent in ampullary gland and ampulla ductus deferentis. In the lamina propria of all organs nuclear labeling with 3H DHT was generally moderate and existed only in some cells, with the highest number in the ampulla ductus deferentis. With 3H E2, nuclear labeling in the lamina propria showed a high intensity in all organs, except in ventral and dorsal prostate which remained unlabeled. Many labeled cells were found in the deferent duct and its ampulla, while in the other organs only a few cells showed nuclear labeling with 3H E2. In the smooth muscle sheath of all organs, some muscle cells were moderately labeled with 3H DHT, but not with 3H E2. The results indicate the presence of nuclear receptors in male accessory sex organs for both dihydrotestosterone and estradiol. The differential patterns of 3H DHT and 3H E2 nuclear uptake suggest differential sensitivities of the individual organs and their tissue compartments for androgens and estrogens.

Animals↗

PubMed1985

Reversible changes in rat spermatogenesis induced by an antifertility substance (Gossypol). A histochemical report.

Male rats received Gossypol 30 mg/kg body mass daily through intubation for 30 and 60 d. The testes were processed for histological and histochemical lipid staining, thiamine pyrophosphatase (TPPase), and alpha-glycerophosphate dehydrogenase (alpha-GPDH)--examinations. Gossypol induced effects were: various types of deformations of elongated spermatids, and their loss of orientation towards the lamina propria during the maturation phase; displacement of germ cells and occasionally also of Sertoli cells towards the lumen of the seminiferous tubule in form of a "puff". TPPase was observed in the supranuclear region of dislocated round spermatids and pachytene spermatocytes. alpha-GPDH was observed in the split pieces of mid- and tail pieces of elongated spermatids enclosed in the "puff". The induced effects were reversible.

Animals↗

PubMed1985

A combined autoradiographic and immunocytochemical study of 3H-corticosterone target neurons and catecholamine neurons in rat and mouse lower brain stem.

Target neurons for 3H-corticosterone were identified by autoradiography and tyrosine hydroxylase containing neurons were identified by immunocytochemistry in the same sections of lower brain stem of 38-day-old rats, 10-day-old rats and adult mice. In all animals studied, the same topographic distribution of neurons was found which exhibited a nuclear accumulation of 3H-corticosterone. Target neurons for 3H-corticosterone were widely distributed in the brain stem. Motor neurons of the cranial nerves and certain neurons of the reticular formation were among the most heavily labeled cells. Neurons containing immunoreactive tyrosine hydroxylase were detected in all of the classical noradrenergic and adrenergic cell groups. Tyrosine hydroxylase containing neurons did not concentrate radioactivity, but were found in close proximity to neurons which concentrated the radiolabeled glucocorticosteroid, especially in the ventrolateral medulla (area A1) and in the ventrolateral pons (area A5). These results do not support, but do not exclude, a direct genomic action of corticosterone on catecholamine neurons in the lower brain stem.

Animals↗

PubMed1985

Autoradiographic binding studies with [3H]oestradiol and [3H]dihydrotestosterone in the autonomic genital ganglion (plexus of Frankenhäuser) of the mouse.

Male, female and Tfm mice (testicular feminization) were injected with [3H]oestradiol or [3H]dihydrotestosterone, and autoradiograms prepared of male accessory sex organs and of the cervico-vaginal portion of the female reproductive tract. After injection of [3H]oestradiol in male, female and Tfm animals a nuclear concentration of radioactivity was found in a subpopulation--about 20-30%--of the neurons of the genital ganglion. No such concentration was seen after [3H]dihydrotestosterone. The results suggest a direct genomic effect of oestradiol on certain neurons of the autonomic genital ganglion in both sexes.

Androgen-Insensitivity Syndrome↗

PubMed1985

Rapid down regulation of beta adrenergic receptors by combining antidepressant drugs with forced swim: a model of antidepressant-induced neural adaptation.

The hypothesis that behavioral responses to antidepressant drugs in the forced swim test are related to a rapid neural adaptation produced by the combination of drug treatment and swim stress was explored. As a measure of adaptation, brain beta adrenergic receptors were assayed using [3H]dihydroalprenolol [( 3H]DHA) binding to brain membranes from rats that were processed in the forced swim test. The combination of swim stress and imipramine treatment antagonized immobility induced by forced swimming and resulted in a reduction in [3H] DHA binding to membranes from forebrain preparations which did not include the corpus striatum. Administration of antidepressant drugs from other chemical classes, including pargyline, iprindole and nomifensine, also reduced immobility induced by the forced swim and produced a reduction in [3H]DHA binding to forebrain membranes. In homogenates of the corpus striatum, [3H]DHA binding was not altered by swim stress combined with antidepressant drug treatment. Chlordiazepoxide was without an effect on immobility or beta receptor binding when combined with forced swim. Even though atropine and amphetamine exhibited a positive activity in the forced swim test, they did not reduce [3H]DHA binding. Therefore, by combining behavioral and neurochemical analysis of animals processed in the forced swim test, it may be possible to differentiate, with greater confidence, potential antidepressant drugs from "false positives." The present studies support the hypothesis that antidepressant drug action in the forced swim test involves a rapid neural adaptation as reflected by the down regulation of beta adrenergic receptors. Thus, this behavioral paradigm may serve as a model of adaptive mechanisms induced by antidepressant drugs.

Adaptation, Physiological↗

PubMed1984

Immunocytochemical localization of corticotropin releasing factor (CRF)-like immunoreactivity in the thalamus of the rat.

The distribution of corticotropin releasing factor (CRF)-immunoreactive structures in the rat thalamus was studied after treatment with high doses of colchicine (100 micrograms/100 g b.wt.) with peroxidase-antiperoxidase (PAP) immunocytochemistry in vibratome sections. CRF-immunopositive perikarya were found in the 'posteromedial complex' of the thalamus, including the ventromedial, paracentral, mediodorsal, rhomboid, parafascicular nuclei, centrum medianum and ventromedial portion of the posterolateral nucleus. In addition, CRF-containing perikarya were observed in the pretectal and subthalamic nuclei. CRF-immunoreactive processes were seen in most of the medial nuclei of the thalamus. The presence of CRF-immunopositive structures in the thalamus suggests that CRF not only functions as a hypophysiotropic hormone regulating the release of ACTH and beta-endorphin from the pituitary, but also as a neurotransmitter or neuromodulator, playing an important role in nociception and analgesia.

Afferent Pathways↗

PubMed1984

Monosodium glutamate lesions in rat hypothalamus studied by immunohistochemistry for gonadotropin releasing hormone, neurotensin, tyrosine hydroxylase, and glutamic acid decarboxylase and by autoradiography for [3H] estradiol.

Adult male and female rats treated neonatally with monosodium glutamate (MSG) exhibit lesions in the arcuate nucleus of the hypothalamus. Immunohistochemical analysis of the distribution of tyrosine hydroxylase (TH), glutamic acid decarboxylase (GAD), neurotensin (NT) and gonadotropin-releasing hormone (GnRH) reveals substantial destructions of tuberoinfundibular dopamine and NT systems accompanied by a marked reduction of immunoreactivity in the median eminence. GAD immunoreactivity in the arcuate nucleus and median eminence is greatly reduced, while GnRH containing structures in the mediobasal hypothalamus are not noticeably affected. Evaluation of autoradiograms after intravenously administered [3H] estradiol in the ventral hypothalamus indicate an almost complete loss of target neurons in the arcuate nucleus but not in the nearby ventromedial nucleus. The results suggest that: (a) NT- and dopamine-containing neurons of the arcuate nucleus project to the median eminence via tuberoinfundibular NT and dopaminergic pathways; (b) GABA in the median eminence originates to a major extent from neurons of the arcuate nucleus through a tuberoinfundibular GABAergic system; (c) GnRH is produced in the rat outside the arcuate nucleus; (d) the MSG-induced lesion in the basal tuberal region abolishes or strongly diminishes estradiol target neurons in the arcuate nucleus.

Animals↗

PubMed1984

Target neurons for [3H]corticosterone in the rat spinal cord.

Rats were injected with [3H]corticosterone and their spinal cords processed for autoradiography. Nuclear concentration of the tritiated steroid was observed in motor neurons in cervical, thoracic, lumbar, and sacral regions. Nuclear concentrations of [3H]corticosterone was also observed in certain neurons of laminae VII and III in all levels of the spinal cord. Injection of unlabeled corticosterone 5 min before the [3H]corticosterone injection abolished the nuclear concentration of the adrenal steroid. These results provide the morphological basis for a direct genomic action of corticosterone in spinal motor neurons and in neurons of laminae III and VII.

Adrenalectomy↗

PubMed1984

Topographical and developmental studies on target sites of 1,25 (OH)2 vitamin D3 in skin.

Tritium-labeled 1,25 (OH)2 vitamin D3, when injected into vitamin D-deficient adult and pregnant rats is concentrated and retained strongest in nuclei of cells in the outer root sheath of the hair, followed by the stratum granulosum, spinosum, and basale of the epidermis. In the hair follicle, in addition to the most heavily labeled outer root sheath, nuclear labeling exists also in cells of the hair bulb and of the inner root sheath, as well as in basal cells of the sebaceous gland. In contrast, cells of the dermal papilla and the connective tissue of the dermis are generally unlabeled, except for labeled cells in the outer connective tissue sheath at the infundibulum of vibrissae of 20-day fetal rats and a few scattered labeled cells in the dermis, probably macrophages. In the developing hair, in 18- and 20-day fetal rats, a distinct topographic pattern of labeled cells can be seen, which is characteristic of the different stages of hair follicle development. In the hair germ, heavily labeled cells appear first in the stratum spinosum. In the hair peg, they remain in this position in its juxtaepidermal portion; however, when a dermal papilla develops, heavily labeled cells assume a marginal position. This suggests a sequential epidermal-epidermal and mesenchymal-epidermal receptor induction. Injection of tritium labeled 25 (OH) vitamin D3 did not show nuclear concentration in these tissues and excess unlabeled 25 (OH) vitamin D3--unlike excess 1,25 (OH)2 vitamin D3--did not prevent nuclear uptake of tritium labeled 1,25 (OH)2 vitamin D3. The results indicate differential effects of 1,25 (OH)2 vitamin D3 on different structures in the epidermis and dermis.

Aging↗

PubMed1984

Differential distribution of dihydrotestosterone and estradiol binding sites in the epididymis of the mouse. An autoradiographic study.

The distribution of androgen and estrogen binding sites in the mouse epididymis was assessed by autoradiography with 3H dihydrotestosterone (3H DHT) and 3H estradiol (3H E2). Nuclear labeling with 3H DHT in principal cells of the epithelium is high in the caput, low in the corpus, and high again in the cauda. 3H E2 also binds to the nuclei of principal cells. The pattern is distinct from 3H DHT: nuclear labeling is highest in the ductulus efferens and high in the caput, but low or absent in corpus and cauda. Apical cells in caput and clear cells in corpus and cauda are moderately labeled with 3H DHT but heavily labeled with 3H E2. Connective tissue cells show variable labeling with both hormones, being more pronounced with 3H E2. Smooth muscle cells are also labeled to varying degrees with both hormones. The different binding patterns of 3H DHT and 3H E2 and the results of the competition studies with unlabeled compounds demonstrate that in the epididymis besides the specific nuclear receptors for androgen also estrogen receptors are present.

Animals↗