Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:1.11.1.7 (peroxidase)
65,474 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Adrenocorticotropin and gonadotropin producing cells were localized in the adenohypothysis of normal Lerots by using anti-beta 1-24 ACTH, anti-LH, anti-LH beta, anti-PMSG antisera. In order to study their fine structure two techniques were employed: a superimposition technique which consists of detailed comparisons between the same cells in light, fluorescence and electron microscopic preparations and an immunocytochemical technique on ultra-thin sections using the peroxidase anti-peroxidase complex technique. The superimposistion technique allows an excellent description of cell ultrastructure of individually identified cells of each type. With this method we were able to describe the corticotropin secreting cells as lucent cells with electron dense granules ranging in size from 2500 to 3500 A. The gonodotropin secreting cells are darker and their granules are about 2000 A in diameter.
...
PMID:Characterization by different techniques of adrenocorticotropin and gonadotropin producing cells in lerot pituitary (Eliomys quercinus). 16 69

Adenohypophysial primordia of rat embryos at 13 to 15 days gestation were cultured in Parker 199 synthetic medium for 2 to 11 days. At the end of the culture period their fine structure and the presence of immunoreactive trophic hormones using the peroxidase-labeled antibody technique were investigated. The degree of differentiation in the glands depends largely on the age of the embryos furnishing the explants. Cultured pituitaries explanted on the 13th day of gestation contain only ACTH-positive cells and about 15% of the cells are granular. The granules are 50-100 nm in diameter in some cells, while in other cells they range from 50 to 200 nm. In cultivated adenohypophysial primordia of embryos on the 15th day of intrauterine life ACTH, prolactin, LH and TSH cells are evident, but only the same two kinds of granular cells can be observed with the electron microscope. The extent of cytodifferentiation in the glands explanted on the 14th day of gestation is intermediate between the two other groups. The data suggest that the fetal rat pituitary has the capacity of self-differentiation but to a lesser extent than that of the in situ hypophysis.
...
PMID:Cell differentiation of the fetal rat anterior pituitary in vitro. 18 70

The onset of hormone synthesis in the rat fetal pituitary gland was studied with the use of the peroxidase labelled antibody method. On the 16th day of fetal life, cells containing immunoreactive ACTH appeared in the primordial cell outgrowth of the Rathke's pouch. In some fetuses, also prolactin cells could be detected at the same developmental stage and these cells were present consistently on subsequent days. Differentiation of ACTH and prolactin cells was followed by onset of TSH, LH and GH synthesis on the 17th, 18th and 19th day of gestation, respectively.
...
PMID:Functional differentiation of the fetal anterior pituitary cells in the rat. 18 42

Monolayer cultures of trypsin-dispersed cells of the rat adenohypophysis were grown for 5 to 54 days. ACTH was localized by immunocytochemistry using an antiserum to synthetic ACTH1-28 prepared in rabbit and sheep anti-goat immunoglobulin coupled with peroxidase. ACTH content of the culture medium was measured by radioimmunoassay. Corttion time. The corticotrophs retained their essential morphological characteristics. Immunological staining was found in the secretory granules, some tubular or saccular structures, parts of the rough endoplasmic reticulum, and the cytoplasmic matrix. Immature secretory granules in the Golgi apparatus as well as some Golgi elements showed different degrees of immunoreactivity. In agreement with the high ACTH content of the culture medium the number, size and shape of the secretory granules, the active Golgi apparatus, the high amount of extragranular ACTH as well as pictures suggesting granule extrusion claim for a high ACTH synthesis and transport (and low ACTH storage) in the cultured corticotrophs.
...
PMID:Corticotroph cells in primary cultures of rat adenohypophysis: a light and electron microscopic immunocytochemical study. 18 91

A radioimmunoassay for plasma ACTH has been developed utilizing highly purified human ACTH (Li) labelled with 125I by the lactoperoxidase method as a tracer and an ACTH antibody produced by immunization of rabbits with ACTH-Z (Organon). The assay is highly specific, reproducible and sensitive to 20 pg of ACTH per ml. Utilizing this technique, endogenous ACTH secretion, adrenal responsiveness to endogenous ACTH and hypothalamic pituitary adrenal feedback mechanisms have been assessed in normal subjects and in patients with Cushing's syndrome due to adrenocortical hyperplasia and nodular cortical hyperplasia. The potential effect of a negative feedback mechanism on the circadian rhythmicity after SU-4885 administration was assessed by initiating SU-4885 either at 9 p.m. or 8 a.m. In normal subjects, the circadian rhythm of ACTH was persistent and independent of a decrease in cortisol. However, in a single case of Cushing's syndrome due to adrenocortical hyperplasia, the circadian rhythm was different from that of normal subjects, possibly influenced by a negative feedback mechanism when SU-4885 was initiated at 8 a.m. In Cushing's syndrome due to adrenocortical and nodular cortical hyperplasia, a significant correlation was observed between the mean plasma ACTH and urinary 17-OHCS values before and after SU-4885 administration (r=0.743, p less than0.01). A significant correlation was also obtained in normal subjects between plasma ACTH and urinary 17-OHCS values (r=0.889, p less than 0.01). However, there was quantitatively more 17-OHCS excreted in the urine for a given plasma ACTH level in patients with Cushing's syndrome than in normal subjects. To assess the relative biological activity of endogenous and exogenously administered ACTH, the ratio of daily 17-OHCS during SU-4885 administration and Cortrosyn-Z administration was expressed as the Cortrosyn Equivalent Quotient (C.E.Q.). The correlation between plasma ACTH and C.E.Q. was similar and significant for normal subjects and patients with Cushing's syndrome (r=0.670, p less than 0.01). These data suggest that there is hyper-responsiveness of the adrenal glands to endogenous ACTH in Cushing's syndrome due to adrenocortical hyperplasia and nodular cortical hyperplasia and that the adrenal hyperactivity is not engendered by a qualitative change in the ACTH release from the pituitary gland. To assess pituitary suppressibility, dexamethasone was administered 40 days or more later following total adrenalectomy in 9 patients with Cushing's syndrome, 6 with adrenocortical hyperplasia and 3 with nodular cortical hyperplasia. One day after discontinuation of substitution therapy, 2 mg of dexamethasone was administered orally followed on successive days by 4 and 8 mg doses. In each instance, dexamethasone was given at midnight and the plasma ACTH concentration was determined at 9:00 a.m. on the day before and after administration of the dexamethasone. A patient with Addison's disease was studied as a control...
...
PMID:[ACTH secretion and adrenocortical responsiveness in Cushing's syndrome due to adrenocortical hyperplasia (author's transl)]. 19 54

Locally recurrent, poorly differentiated carcinoma of the prostate was associated with hypokalemic alkalosis, marked hypernatremia, diabetes mellitus of recent onset, and hyperosmolar syndrome. These findings, with mild hypertension, in the absence of clinical features of Cushing's syndrome, suggested an ectopic ACTH syndrome. Plasma ACTH and cortisol levels were markedly elevated, and failed to suppress in response to either low or high-dose dexamethazone administration. The patient's condition deteriorated rapidly. Autopsy findings included carcinoma extensively infiltrating the prostate with extension to the urinary bladder, and metastases confined to the pelvic nodes and soft tissues. The adrenal glands weighed 23 g and showed diffuse hyperplasia. Extract of the prostatic tumor was analyzed for ACTH and showed approximately 40 times normal plasma levels (or about 4,010 pg/g of tissue); ultrastructural features showed secretory granules consistent with ACTH content of the tumor cells. Such cells were positive when stained for ACTH by peroxidase-tagged immunochemical methods. The case fulfills all established criteria for relating excess corticosteroid production and nonpituitary tumors.
...
PMID:Ectopic ACTH, prostatic oat cell carcinoma, and marked hypernatremia. 19 43

In order to investigate the influence of the central nervous system on the functional differentiation of the fetal anterior pituitary gland, the pituitary gland of anencephalic and normal fetus was studied by the peroxidase-labeled antibody method for the localization of various hormones. The only abnormality of pituitary endocrine cells in anencephaly was a marked decrease of ACTH cells. In the normal development, ACTH appeared as the earliest hormone in 5 weeks. And all other hormones were seen in 13 weeks. The reason for the decrease of ACTH cells in anencephaly was speculated to be a suppression at an early developmental life. The experimental observations done in rats using MAM might support this speculation. The adrenal glands of anencephalus showed atrophy of the fetal cortex which was considered to correlate with the decrease in number of ACTH cells. Absence of the histochemical activity of alkaline phosphatase in the permanent cortex of anencephaly may indicate absence or inadequate stimulation by fetal ACTH. Further experimental studies in suppression of the central nervous system in early developmental life seemed to confirm the above speculation in functional differentiation of the fetal pituitary and adrenal glands.
...
PMID:Functional prenatal development of anencephalic and normal anterior pituitary glands. In human and experimental animals studied by peroxidase-labeled antibody method. 19 43

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.
...
PMID:Autoradiographic studies of 3H-dexamethasone uptake by immunocytochemically characterized cells of the rat pituitary. 20 Mar 61

Pituitary glands were examined using reference staining (hematoxylin and eosin, periodic acid-Schiff and alcian blue) and the peroxidase-labeled antibody method, for 1) "invading" anterior cells in the posterior lobe, 2) intermediate colloid forming follicles, and 3) pars tuberalis cells. The results showed: 1) that the majority of cases possessed "invading" anterior cells of various amount. Most of these cells were positive for ACTH1-18, ACTH17-39 and betaMSH. However, on a few occasions, scattered GH, PRL, FSHalpha, FSHbeta, LHbeta and even TSHbeta cells were also present. 2) Colloid forming follicular cells were mostly ACTH cells, but also contained occasional other hormone-secreting cells. Hormone negative cells were correlated with salivary type epithelium. Well established acinic type salivary glands and ciliated epithelium were negative for any hormones immunohistochemically. 3) Pars tuberalis cells were predominantly gonadotrophs but also included TSHbeta and ACTH cells. Some cells appeared to contain both FSHbeta and LHbeta. When these cells underwent squamous metaplasia, they seemed to lose their hormone secreting activity.
...
PMID:An immunohistochemical study of epithelial cells in the posterior lobe and pars tuberalis of the human adult pituitary gland. 21 13

Slices of unembedded rat anterior pituitaries, fixed with a periodate-lysine-paraformaldehyde (PLP) fixative, were incubated with guinea pig antiserum to ACTH and stained with a peroxidase-conjugated IgG fraction of anti-guinea pig gamma-globulin serum from rabbits. The fine structure of the stained cells was identical to that of the ACTH-secreting cell, as described by Siperstein and coworkers. Immunoreactive granules were mainly located at the periphery of the cell. Numerous granules of the inner cytoplasm and also the Golgi complex were nonreactive to the antiserum. The differential labeling for granules and Golgi apparatus peptide.
...
PMID:Granules and Golgi vesicles with differential reactivity to ACTH antiserum in the corticotroph of the rat anterior pituitary. 21 25


1 2 3 4 5 6 7 8 9 10 Next >>

---