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  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neuroendocrinology 2 (1990), S. 0 
    ISSN: 1365-2826
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Vasopressin (VP) cells in the bed nucleus of the stria terminalis, medial amygdaloid nucleus and supraoptic and paraventricular nuclei are influenced by gonadal steroids. The present paper examined whether VP cells in the bed nucleus of the stria terminalis, medial amygdaloid nucleus, and supraoptic and paraventricular nuclei contain estrogen receptors. Brains from adult short-term castrated, colchicine-treated male rats were fixed with 4% paraformaldehyde and 0.5% glutaraldehyde. In the immunocytochemical double-staining procedure Vibratome sections were first incubated with an estrogen receptor antibody (#H222) and stained with diaminobenzidine-Ni+. Following methanol-hydrogen peroxide washes, sections were incubated with anti-neurophysin and stained with diaminobenzidine. Parvocellular cells in the bed nucleus of the stria terminalis and medial amygdaloid nucleus were double-stained with a blue-black nucleus (indicating the estrogen receptors) surrounded by brown cytoplasm (resulting from VP-neurophysin-immunoreactivity). Our results provide the first direct anatomical evidence supporting the hypothesis that gonadal steroids' influence of parvocellular VP cells in the bed nucleus of the stria terminalis and medial amygdaloid nucleus is mediated directly via estrogen receptors localized in nuclei of VP neurons. We were unable to co-localize any estrogen receptors in VP and oxytocin cells of magnocellular size in the supraoptic, paraventricular and anterior commissural nuclei, suggesting that estrogen indirectly affects these magnocellular hypothalamic cells.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neuroendocrinology 2 (1990), S. 0 
    ISSN: 1365-2826
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: It is well established that flank marking behavior in the Golden hamster is controlled by vasopressin-sensitive neurons localized to the anterior hypothalamus; however, the source(s) of vasopressinergic innervation to this area is unknown. Previous analysis by immunocytochemistry showed distinct populations of vasopressinergic magnocellular neurons localized to the supraoptic nucleus, paraventricular nucleus and the nucleus circularis that did not project to the neurohypophysis. In the present study, these same hypothalamic nuclei were lesioned by microinjection of kainic acid to determine which, if any, of these populations of vasopressin neurons are involved in the control of flank marking. Unilateral lesions in the areas of the nucleus circularis and supraoptic nucleus at the rostro-caudal plane of the anterior hypothalamus abolished odor-induced flank marking behavior. Lesions in the paraventricular nucleus at the level of the anterior hypothalamus did not consistently inhibit flank marking, while lesions of magnocellular neurons rostral or caudal to the anterior hypothalamus were ineffective. The microinjection of vasopressin into the anterior hypothalamus following lesion of the paraventricular and supraoptic nuclei stimulated flank marking, evidence that treatment with kainic acid did not damage the efferent component of this behavior. However, animals with lesions in the nucleus circularis did not respond to the microinjection of vasopressin; hence, it is uncertain whether lesions in this area disrupt vasopressinergic innervation to the anterior hypothalamus or simply destroy the motor neurons controlling flank marking. In summary, the data clearly demonstrate that vasopressin neurons localized primarily to the medial aspect of the supraoptic nucleus are necessary for sensory integration of odor-induced flank marking, and as such, may be one possible source of neurotransmitter controlling this behavior.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1365-2826
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Oxytocin (OT) plays a role in reproduction at the level of the pituitary and mammary glands and uterus. This OT is synthesized in the hypothalamo-neurohypophyseal system (HNS). A number of observations have suggested that estrogens regulate the production of OT in the HNS. In this study the effect of 17β-estradiol on the activity of the OT gene promoter was examined as well as the effect of 17β-estradiol in vivo on OT messenger ribonucleic acid (mRNA) and peptide revels in the rat HNS. Vasopressin (VP) and its mRNA were also determined in the in vivo studies. The direct transcriptional stimulation of OT gene expression by 17β-estradiol was studied in two different heterologous expression systems. When a plasmid having nucleotides −363 to +16 of the rat OT gene fused to the firefly luciferase reporter gene was co-transfected with an estrogen receptor expression vector in P19 embryonal carcinoma cells, luciferase activity was stimulated 80-fold by 17β-estradiol. In estrogen receptor containing MCF-7 cells transfected with a plasmid having nucleotides −188 to +16 of the rat OT gene fused to the chloramphenicol acetyl transferase gene, 17β-estradiol induced the expression of the chloramphenicol acetyl transferase gene through the cloned promoter element. After in vivo treatment of ovariectomized rats with 17β-estradiol, levels of OT mRNA and VP mRNA were measured in microdissected supraoptic and paraventricular nuclei as well as VP and OT levels in these nuclei and the pituitary gland. As compared to non-treated ovariectomized rats there was no difference in contents of OT mRNA and VP mRNA in these hypothalamic nuclei and in levels of the peptides in paraventricular nuclei and the pituitary gland. A 30% reduction of the OT content of the supraoptic nuclei only was found, while the VP content did not change. To explain the results immunocytochemical analyses of the hypothalamus were performed, showing that the estrogen receptor was absent in the magnocellular neurons of the supraoptic and paraventricular nuclei. The results demonstrate that the 5’flanking region of the OT gene confers estrogen-sensitivity to transcription of the OT gene. This potential to respond to estrogens is not used in the OT-producing neurons of supraoptic and paraventricular nuclei probably due to the absence of the estrogen receptor.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 215 (1986), S. 342-350 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Ovaries from normal mature rats, rats injected with testosterone propionate (TP), and from aged rats were removed, and large antral follicles examined by quantitative cytochemical techniques in order to analyze possible enzymatic defects that relate to follicular steroidogenesis. The ovaries from the TP-injected and the aged rats were polycystic. Lipid deposition was analyzed in frozen sections stained with Sudan black. A microdensitometer was used to measure Δ5-3β -hydroxysteroid dehydrogenase (3βOHD) activity and G-6-PD type IH generation in the theca, and in peripheral region, antral region, and corona radiata of large antral follicles. 3βOHD is the enzyme that converts pregnenolone to progesterone. Type IH generation is related to the conversion of androstenedione to estradiol. Lipid droplet deposition was comparable in the three types of follicles. Compared to that in normal preovulatory follicles, 3βOHD activity was similar in identical regions of large antral follicles in TP-injected rats, but less in the theca and peripheral region of the membrana granulosa of the aged rat. G-6-PD type IH generation was less in the peripheral region of large antral follicles of both TP-injected and aged rats than in preovulatory follicles. Type IH generation was also less in the theca of TP-injected rats than in the theca of normal rats. This study provides evidence that in spite of their normal appearance, large antral follicles in polycystic ovaries are not physiologically sound. Furthermore, the enzymatic disturbance appears to be different in different types of polycystic ovaries.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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