Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0155339 (Brown)
 12,436 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It is suggested that in addition to stimulating the thyroid gland (i.e., the main regulator of metabolic-rate in adults) thyroid-stimulating hormone (T.S.H.) stimulates the second thermoregulatory organ (i.e., the brown adipose tissue). Brown fat functions as a thermogenic organ in hibernating animals, in newborn infants, and during cold acclimatisation. However, B.F. may persist in childhood and in some adults. Its hypertrophy in response to T.S.H. could account for certain unexplained features of myxoedema in which serum-T.S.H. is raised, such as swelling of the supraclavicular fat pad and the less commonly encountered symptoms of ascites or pericardial and pleural serous effusions which can persist for years in undiagnosed cases and respond rapidly to thyroxine when serum-T.S.H. returns to normal. Lack of thyroxine is not the cause of these features since they are not found in pituitary myxoedema, where thyroid hormone levels are as low but T.S.H. is absent.
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PMID:Possible stimulation of thermogenesis in brown adipose tissue by thyroid-stimulating hormone. 4 49

The cistron A protein induced by phage varphiX174 nicks (produces a single-strand break in) the viral strand of the superhelical varphiX duplex DNA, thereby forming a complex with the DNA. The protein, seen bound to the DNA in the electron microscope, was located in the restriction endonuclease fragment between nucleotides 4290 and 4330 on the varphiX map [Sanger, F., Air, G. M., Barrel, B. G., Brown, N. L., Coulson, A. R., Fiddes, J. C., Hutchison, C. A., III, Slocomb, P. M. Y. & Smith, M. (1977) Nature 265, 687-695]. Replication also was initiated at this point, thus identifying the site of cistron A protein nicking and binding as the origin of replication. The cisA-DNA complex (separated from free cistron A protein), upon the addition of Escherichia coli rep protein, ATP, and DNA binding protein, is unwound to generate a single-stranded linear [presumably the nicked (+) strand] and a circular [presumably the (-) strand] molecule. The cisA-DNA complex, upon the further addition of DNA polymerase III holoenzyme and deoxynucleoside triphosphates, supports replication to generate viral, single-stranded circles, as many as 15 circles per cisA-DNA complex. The replicating intermediates seen in the electron microscope are a novel form of "rolling circle" [Gilbert, W. & Dressler, D. H. (1969) Cold Spring Harbor Symp. Quant. Biol. 33, 473-485]. The 5' end (presumably with the cistron A protein bound to it) is locked in the replication fork and loops back to accompany the strand-separation and replication fork around the template [(-) strand] circle. Thus, the multiple functions of cistron A protein include: (i) nicking the viral strand at the origin of replication to initiate a round of replication, (ii) participating in a complex which supports fork movement in strand separation and replication, (iii) nicking again at the regenerated origin to produce a unit-length DNA, and (iv) ligating the newly generated 3'-OH end to the 5'-phosphate-complexed end to form a circular viral molecule.
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PMID:phiX174 cistron A protein is a multifunctional enzyme in DNA replication. 26 83

Brown adipose tissue mitochondria predominantly oxidize fatty acids in order to generate heat for non-shivering thermogenesis, and have an unusually high capacity for net transfer of long-chain fatty acyl groups from the outer to the inner (matrix) compartment. The activities of the "outer" and "inner" carnitine long-chain acyltransferases have been estimated in isolated mitochondria of cold-acclimated guinea pits by the continuous spectrophotometric recording of the redox level of flavoproteins in the acyl-CoA dehydrogenase pathway. This redox level is determined by the intramitochondrial content of acyl-CoA under the selected experimental conditions. The apparent initial rate of the "inner" acyltransferase (palmitoyl-L-carnitine added) is three order of magnitudes higher than the "outer" acyltransferase (palmitoyl-CoA added), and this difference is not influenced by the substrate concentration, pH and reaction temperature. Thus, the "outer" acyltransferase reaction is rate limiting in the transfer of long-chain acyl groups across the inner membrane of these mitochondria and catalyzes a non-equilibrium reaction in the intact organelle. Estimates of the absolute rate of the "outer" long-chain acyltransferase indicate that it exceeds that of rat liver mitochondria by a factor of 20.
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PMID:On the rate-limiting step in the transfer of long-chain acyl groups across the inner membrane of brown adipose tissue mitochondria. 62 16

48 women complaining of climacteric disorders were treated with an estrogen preparation for 1 year. Before an intervalls of 2 month during the treatment period studies of the Kupperman index, the vaginal karyopcnotic index and 3 neurovegatative (hemodynamic) tests were carried out: The orthostase-test according to Schellong, the cold-pressor-test according to Hines and Brown, the Pholedrin (Veritol-)test. During estrogen substitution the following alterations could be stated: A significant decrease of systolic and diastolic blood pressure values, a tendency of adjusting the systolic blood pressure values after standing up to the values in rest (Schellong-test I), a shortening of the interval needed to establish stable values of blood pressure and heart frequency, a tendency to reduce the increase of blood pressure in the cold pressor test, and a significant amplification of the increase of blood pressure and blood pressure amplitude in the Pholedrin test. These results are believed to indicate an alteration of vegetative reactivity in the parasympathicomimetic direction. Estrogens seem to exert a favourable influence on the mechanism of blood pressure regulation.
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PMID:[The neurovegatative reaction-situation in climacteric. Modification of blood pressure regulation by estrogens]. 93 20

Brown adipose tissue of normal and cold-adapted adult rats has been investigated morphologically and cytochemically. In thin-sections catalase-positive particles appear as circular, oval or elongated profiles lying either as single particles or forming groups. Biochemical studies on peroxisomal enzymes show an increase of catalase activity to the tenfold amount after cold adaptation. The tissue is devoid of D-aminoacid oxidase and glycolate oxidase, while low activities of middle-chain-alpha-hydroxyacid oxidases could be detected. The catalase-positive particles were purified by differential and is lower than that of the liver peroxisomes. Enzymic investigations of the fractions render it probably that particles contain carnitine acetyltransferase, whereas they are lacking NAD-dependent glycerophosphate dehydrogenase. The pellets derived from the gradient centrifugation have been checked morphologically for purity. After performing DAB-cytochemistry for identification of the peroxidatic activity of catalase, most of the particles were shown to be structurally intact and homogeneously filled with reaction product.
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PMID:Enzymic and morphological studies on catalase positive particles from brown fat of cold adapted rats. 100 71

Five healthy male volunteers received 500 mg Aldactone orally together 100 muCi 3H-20-21-spironolactone; one elderly patient received 1 mCi 3H-spironolactone without additional 'cold' drug. For 6 days the disposition kinetics of the drug were studied in plasma, urine and feces. The tritium concentrations in plasma reached a peak between 25-40 min after administration amounting to 2-3% of the dose/1. Up to the 12th h, they fell rapidly and showed a monoexponential decline (t 1/2: 2.57 +/- 0.27 days) between the 36th and 96th h. Later, a striking increase in the speed of elimination of radioactivity from plasma (t 1/2: 1.66 +/- 0.21 days) was observed. The biological half-life of labeled material in plasma was longer than that of fluorigenic compounds. 47-57% of the dose were excreted in urine and the remaining amount could be detected in feces (total recovery 90%). The half-life of the urinary excretion rate was distinctly shorter (t 1/2: 0.9 +/- 0.11 days) than that of total radioactivity in plasma. This, together with an observed increase of the polar fraction in urine from 35 up to 85%, which was accompanied by a decrease in plasma from 55 to 35%, suggests either tubular reabsorption or enterohepatic recirculation of lipophilic compounds. TLC-separation of the lipophilic fraction in urine revealed two previously unknown compounds of which the main congener was identified as 3-(3-oxo-7 alpha-methylsulfonyl-6 beta, 17 beta-dihydroxy-4-androsten-17 alpha-yl) propionic acid gamma-lactone, as well as canrenone and the metabolites which have already been described (Karim and Brown, 1972; Karim et al., 1975). This metabolite represents the main lipophilic degradation product in urine within the first hours, whereas the 6 beta-OH-7 alpha-methylsulfinyl-spirolactone leveled off and seemed to be and endexcretion product. For further characterisation, the polar fraction was subjected to acidic hydrolysis. The known metabolic pathways of spironolactone degradation are discussed.
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PMID:Pharmacokinetics of spironolactone in man. 101 47

Brown adipocytes are thermogenic cells which play an important role in energy balance. Their thermogenic activity is due to the presence of a mitochondrial uncoupling protein (UCP). Until recently, it was admitted that in rodents brown adipocytes were mainly located in classical brown adipose tissue (BAT). In the present study, we have investigated the presence of UCP protein or mRNA in white adipose tissue (WAT) of rats. Using polymerase chain reaction or Northern blot hybridization, UCP mRNA was detected in mesenteric, epidydimal, retroperitoneal, inguinal and particularly in periovarian adipose depots. The uncoupling protein was detected by Western blotting in mitochondria from periovarian adipose tissue. When rats were submitted to cold or to treatment with a beta-adrenoceptor agonist, UCP expression was increased in this tissue as in typical brown fat. Moreover, the expression was decreased in obese fa/fa rats compared to lean controls. Morphological studies showed that periovarian adipose tissue of rats kept at 24 degrees C contained cells with numerous typical BAT mitochondria with or without multilocular lipid droplets. Immunocytochemistry confirmed that multilocular cells expressed mitochondrial UCP. Furthermore, the number of brown adipocytes and the density of mitochondrial cristae increased in parallel with exposure to cold. These results demonstrate that adipocytes expressing UCP are present in adipose deposits considered as white fat. They suggest the existence of a continuum in rodents between BAT and WAT, and a great plasticity between adipose tissue phenotypes. The physiological importance of brown adipocytes in WAT and the regulation of UCP expression remain open questions.
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PMID:Occurrence of brown adipocytes in rat white adipose tissue: molecular and morphological characterization. 136 71

We have previously shown that rat allo-selective cells of the CD2+CD5- phenotype were generated in Brown Norway (BN) rats after immunization with allogeneic Wistar/Furth (WF) cells, whereas immunization with semi-allogeneic F1 (WF/BN) cells generated CD2+CD5+ effector T cells. We now report that the allo-selective CD2+CD5- lymphocytes lacked expression of intact CD3 complexes and expressed NKR-P1 molecules although lower as compared to classical NK cells, implicating that these lymphocytes constitute a subset of NK cells. The CD5+ T cells were not cytolytically active in BN rats immunized with WF cells indicating an intersubset regulation with mutually exclusive activation of either allo-selective T cells or allo-selective NK cells. Cold target inhibition showed that lysis of both allogeneic target cells and NK-sensitive target cells was mediated by the same NKR-P1 intermediate effector cells. These NK cells lysed WF but not allogeneic Fischer 344 or autologous BN target cells, indicating selective recognition of an allogeneic determinant. Semiallogeneic F1 (WF/BN) target cells were not lysed. Furthermore, target cells from F1 (WF/BN) x WF back-cross hybrids lacking expression of RT1n (self-MHC class I) were susceptible to lysis, whereas back-cross hybrids expressing RT1n were protected from lysis, indicating that self-MHC molecules conferred protection from lysis. These findings implicate the existence of NKR-P1intermediate and NKR-P1high NK cell subsets with different regulation and function in vivo.
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PMID:In vivo induced allo-reactive natural killer cells. 138 May 32

Brown adipose tissue (BAT) is a major site of nonshivering thermogenesis (NST) during cold acclimation for most mammals. Repetitive nonthermal stress such as immobilization has been shown to enhance the capacity of NST as cold acclimation. In the present study, the effects of running training, another type of nonthermal stress, were investigated on in vitro thermogenesis and the cellularity of interscapular BAT in rats. The rats were subjected to treadmill running for 30 min daily at 30m/min under 8 degrees inclination for 4-5 weeks. In vitro thermogenesis was then measured in minced tissue blocks incubated in a Krebs-Ringer phosphate buffer containing glucose and albumin at 37 degrees C, using a Clark type oxygen electrode. The trained rats showed less body weight gain during the experiment. The weights of BAT and epididymal white adipose tissue were smaller in the trained rats. Noradrenaline- and glucagon-stimulated oxygen consumption were also significantly smaller in the trained rats. The tissue DNA level was greater in the trained rats, but the DNA content per tissue pad did not significantly differ. The results indicate that running training reduces BAT thermogenesis, possibly as an adaptation to conserve energy substrates for physical work.
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PMID:Effects of running training on in vitro brown adipose tissue thermogenesis in rats. 163 84

Brown adipose tissue (Na(+)-K+)-ATPase activity, in vitro glucose uptake and 2-aminoisobutyric acid uptake, as well as mitochondrial GDP-binding and succinate dehydrogenase activity were determined in order to study the relationship between these parameters in control, cold acclimated and cafeteria-fed rats. GDP-binding, (Na(+)-K+)-ATPase and glucose uptake were increased in interscapular brown adipose tissue from cold-acclimated and cafeteria-fed rats, whereas 2-aminoisobutyric acid uptake was only increased in cafeteria-fed rats. GDP-binding and (Na(+)-K+)-ATPase activity showed a high correlation coefficient suggesting a parallel modulation of both systems, which would probably share a common regulation mechanism.
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PMID:Parallel modulation of brown adipose tissue GDP-binding, substrate uptake and (Na(+)-K+)-ATPase activity in the rat. 166 Dec 74


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