Browsing by Author "Corthorn, Jenny"

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    Expression and immunolocalization of endothelin peptides and its receptors, ET A and ET B, in the carotid body exposed to chronic intermittent hypoxia
    (2007) Rey, Sergio; Corthorn, Jenny; Chacon, Cecilia; Iturriaga, Rodrigo
    Increased levels of endothelin-1 (ET-1) in the carotid body (CB) contribute to the enhancement of chemosensory responses to acute hypoxia in cats exposed to chronic intermittent hypoxia (CIH). However, it is not known if the ET receptor types A (ETA-R) and B (ETB-R) are upregulated. Thus, we studied the expression and localization of ETA-R and ETB-R using Western blot and immunohistochemistry (IHC) in CBs from cats exposed to cyclic hypoxic episodes, repeated during 8 hr for 4 days. In addition, we determined if ET-1 is expressed in the chemoreceptor cells using double immunofluorescence for ET-1 ancityrosine hydroxylase (TH). We found that ET-1 expression was ubiquitous in the blood vessels and CB parenchyma, although double ET-1 and TH-positive chemoreceptor cells were mostly found in the parenchyma. ETA-R was expressed in most chemoreceptor cells and blood vessels of the CB vascular pole. ETB-R was expressed in chemoreceptor cells, parenchymal capillaries, and blood vessels of the vascular pole. CIH upregulated ETB-R expression by similar to 2.1 (Western blot) and 1.6-fold (IHC) but did not change ETA-R expression. Present results suggest that ET-1, ETA-R, and ETB-R are involved in the enhanced CB chemosensory responses to acute hypoxia induced by CIH.
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    Expression of kallikrein, bradykinin B2 receptor, and endothelial nitric oxide synthase in placenta in normal gestation, preeclampsia, and placenta accreta
    (2006) Corthorn, Jenny; Germain, Alfredo A.; Chacon, Cecilia; Rey, Sergio; Soto, Gloria X.; Figueroa, Carlos D.; Mueller-Esterl, Werner; Duarte, Ignacio; Valdes, Gloria
    In an effort to define the varied expression of three vasoactive markers in the clinical models of normal placenta/normal invasion (n = 11), preeclampsia/restricted trophoblast invasion (n = 15), and placenta accreta/exaggerated invasion (n = 6), we performed semiquantitative immunohistochemistry for kallikrein, bradykinin 132 receptor, and endothelial nitric oxide synthase (eNOS). In the floating villi, the syncytiotrophoblast expressed more kallikrein in placenta accreta (p < 0.05), than in normal and preeclamptic placentas, while the bradykinin B2 receptor and eNOS were similarly expressed in all groups; in the fetal endothelium, the bradykinin B2 receptor was enhanced in placenta accreta (p < 0.005), but kallikrein and eNOS were similarly expressed in the other two groups. in the extravillous trophoblast, both kallikrein and eNOS expression were higher in placenta accreta (p < 0.001), while the bradykinin B2 receptor signal was only enhanced in preeclampsia (p < 0.05). The presence and localization of kallikrein, the bradykinin B2 receptor, and eNOS in the fetomaternal interface in the three study conditions supports a local role for interrelated vasodilatory/antiaggregating systems. This first report of the variations observed in kallikrein and eNOS in a condition of exaggerated trophoblast invasion supports the participation of vasodilatation in trophoblast migration.
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    The Uterine Placental Bed Renin-Angiotensin System in Normal and Preeclamptic Pregnancy
    (2009) Anton, Lauren; Merrill, David C.; Neves, Liomar A. A.; Diz, Debra I.; Corthorn, Jenny; Valdes, Gloria; Stovall, Kathryn; Gallagher, Patricia E.; Moorefield, Cheryl; Gruver, Courtney; Brosnihan, K. Bridget
    Previously, we demonstrated activation of the renin-angiotensin system in the fetal placental chorionic villi, but it is unknown whether the immediately adjacent area of the maternal uterine placental bed is regulated similarly. This study measured angiotensin peptides, renin-angiotensin system component mRNAs, and receptor binding in the fundus from nonpregnant subjects (n = 19) and in the uterine placental bed from normal (n = 20) and preeclamptic (n = 14) subjects. In the uterine placental bed from normal pregnant women, angiotensin II peptide levels and angiotensinogen, angiotensin-converting enzyme, angiotensin receptor type 1 (AT1), AT2, and Mas mRNA expression were lower as compared with the nonpregnant subjects. In preeclamptic uterine placental bed, angiotensin II peptide levels and renin and angiotensin-converting enzyme mRNA expression were significantly higher than normal pregnant subjects. The AT2 receptor was the predominant receptor subtype in the nonpregnant fundus, whereas all angiotensin receptor binding was undetectable in normal and preeclamptic pregnant uterine placental bed compared with nonpregnant fundus. These findings suggest that the maternal uterine placental bed may play an endocrine role by producing angiotensin II, which acts in the adjacent placenta to vasoconstrict fetal chorionic villi vessels where we have shown previously that AT1 receptors predominate. This would lead to decreased maternal-fetal oxygen exchange and fetal nutrition, a known characteristic of preeclampsia. (Endocrinology 150: 4316-4325, 2009)
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    Urinary vasodilator and vasoconstrictor angiotensins during menstrual cycle, pregnancy, and lactation
    (2001) Valdés, Gloria; Germain, Alfredo M.; Corthorn, Jenny; Berrios, Cecilia; Foradori, Arnaldo; Ferrario, Carlos M.; Brosnihan, K. Bridget