John F. Breininger

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Neuropeptide Y (NPY) stimulates food intake and promotes weight gain, whereas melanocortins have the opposite effect. Yet both peptides are synthesized in the arcuate nucleus, a hypothalamic area involved in energy homeostasis. We report here that mRNA encoding NPY and the melanocortin precursor, proopiomelanocortin (POMC) are expressed in adjacent, but(More)
The decline of leptin (Ob protein) concentrations during fasting is implicated as a signal for increasing the expression of the orexigenic peptide neuropeptide Y (NPY) in the hypothalamus. To test the hypothesis that the effects of food intake on arcuate nucleus NPY activation are mediated by leptin, we performed simultaneous triple in situ hybridization(More)
Three experiments were performed to investigate the hypothesis that leptin action within the caudal brain stem (CBS) contributes to its intake inhibitory effects. The first experiment evaluated the anatomical distribution of leptin receptor mRNA in rat CBS using a sensitive fluorescence in situ hybridization method with a riboprobe specific for the long(More)
In mammals there is a well-established connection between neuropeptide Y (NPY) and the balance between energy intake and expenditure: NPY stimulates food intake and the hypothalamus shows a dramatic increase in NPY mRNA in response to fasting. The widespread occurrence of NPY in the brains of all vertebrates investigated raises the possibility that NPY may(More)
Reduced leptin (Ob protein) signaling is proposed to be a stimulus for the activation of neuropeptide Y (NPY) gene activity and increased expression of mRNA for the long form of the leptin receptor (Ob-Rb) in the hypothalamic arcuate nucleus. To determine if Ob-Rb protein is expressed in arcuate nucleus NPY neurons, we developed an affinity-purified(More)
Several mRNAs which encode for isoforms of the plasma membrane Ca(2+)-transport ATPase (PMCA) are present in adult rat brain. Using in situ hybridization with antisense oligonucleotide probes we found complex patterns of specific hybridization for three isoforms (PMCA1-3). Each rat brain region studied exhibited a distinct pattern of expression of isoforms.(More)
Glycoprotein (GP) IX is a subunit of the von Willebrand receptor, GPIb-V-IX, which mediates adhesion of platelets to the subendothelium of damaged blood vessels. Previous characterization of the GPIX promoter identified a functional Ets site that, when disrupted, reduced promoter activity. However, the Ets protein(s) that regulated GPIX promoter expression(More)
Probes labeled with 33P have potential for widespread use in in situ hybridization because they are better able to detect relatively scarce mRNAs compared with probes labeled with 35S, but the relatively short half-life of 33P is a disadvantage when it is used as a radioactivity standard for quantitative autoradiography. To determine if plastic sections(More)
To increase the sensitivity of fluorescence in situ hybridization (FISH) for detection of low-abundance mRNAs, we performed FISH on cryostat sections of rat hypothalamus with biotin-labeled riboprobes to leptin receptor (ObRb) and amplified the signal by combining tyramide signal amplification (TSA) and Enzyme-Labeled Fluorescent alkaline phosphatase(More)
The arcuate nucleus (ARC) mediates the anorexic effects of leptin and expresses the long form (Ob-Rb) of the leptin receptor. To determine whether ARC leptin binding increases when plasma leptin levels are low during fasting, [125I]-leptin specific binding to rat brain slices was measured by quantitative autoradiography. [125I]-leptin specific binding was(More)