Synergic effects of estradiol and progesterone on regulation of the hypothalamic neuronal nitric oxide synthase expression in ovariectomized mice

Martini, Mariangela; Pradotto, Monica; Panzica, Giancarlo

doi:10.1016/j.brainres.2011.06.017

Cited by 9 publications

(11 citation statements)

References 54 publications

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“…In a previous study conducted in our lab, Martini et al (2011) tested the sexual behavior in gonadectomized female mice subjected to a P and E 2 treatments, confirming that these two hormones work in synergistic fashion to facilitate female receptivity. Interestingly animals tested for lordosis behavior were only receptive after the second cycle of treatment (see Table 2 in Martini et al, 2011). They mimicked the hormonal situation typical of the late proestrus in the E2+P Group, with high levels of E2 and P, the early proestrus in the E2 Group and the diestrus in P Group.…”

Section: Introductionmentioning

confidence: 57%

“…They mimicked the hormonal situation typical of the late proestrus in the E2+P Group, with high levels of E2 and P, the early proestrus in the E2 Group and the diestrus in P Group. In the same study, the authors demonstrated a synergistic effect of both E2 and P on the expression of hypothalamic nNOS in ovariectomized females (Martini et al, 2011).…”

Section: Introductionmentioning

confidence: 74%

“…This study has been performed on sections stored from our previously published study on the effect of E2 and P on the hypothalamic nitrergic system (Martini et al, 2011), therefore animals, treatments and sectioning procedures are the same of the previous paper.…”

Section: Methodsmentioning

confidence: 99%

“…In the present study, using sections from our previous experiment (Martini et al, 2011), we analyze the role played by E 2 and P (alone or together) on the kisspeptin system, including in our analysis not only the RP3V, and the ARC, but also the PVN, the major hypothalamic target of the kisspeptin system.…”

Section: Introductionmentioning

confidence: 99%

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Kisspeptin system in ovariectomized mice: Estradiol and progesterone regulation

et al. 2018

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The kisspeptin system is clustered in two main groups of cell bodies (the periventricular region, RP3V and the arcuate nucleus, ARC) that send fibers mainly to the GnRH neurons and in a few other locations, including the paraventricular nucleus, PVN. In physiological conditions, gonadal hormones modulate the kisspeptin system with expression changes according to different phases of the estrous cycle: the highest being in estrus phase in RP3V and PVN (positive feedback), and in ARC during the diestrus phase (negative feedback). In this work we wanted to study these hormonal fluctuations during the estrous cycle, investigating the role played by progesterone (P) or estradiol (E), alone or together, on the kisspeptin system. Gonadectomized CD1 female mice were treated with P, E or both (E + P), following a timing of administration that emulates the different phases of estrous cycle, for two cycles of 4 days. As expected, the two cell groups were differentially affected by E; the RP3V group was positively influenced by E (alone or with the P), whereas in the ARC the administration of E did not affect the system. However P (alone) induced a rise in the kisspeptin immunoreactivity. All the treatments significantly affected the kisspeptin innervation of the PVN, with regional differences, suggesting that these fibers arrive from both RP3V and ARC nuclei.

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Section: Introductionmentioning

confidence: 57%

Section: Introductionmentioning

confidence: 74%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Kisspeptin system in ovariectomized mice: Estradiol and progesterone regulation

et al. 2018

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“…For example, a series of recent reports indicated the importance of intact ovarian cycle with the natural hormonal fluctuations for nitrergic system in the brain. In this work, which examined mating behavior of female rats, both estrogen and progesterone were found necessary and synergistic in regulating nNOS and NO-mediated neuronal function in the brain regions regulating the corresponding behavior (22,23).…”

Section: Discussionmentioning

confidence: 99%

Altered Neuronal Nitric Oxide Synthase in the Aging Vascular System: Implications for Estrogens Therapy

Lekontseva

Jiang

Schleppe³

et al. 2012

Endocrinology

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Ovarian dysfunction at any age is associated with increased cardiovascular risk in women; however, therapeutic effects of exogenous estrogens are age dependent. Estradiol (E2) activates neuronal nitric oxide synthase (nNOS) in vascular cells. Because nNOS is prone to uncoupling under unfavorable biochemical conditions (as seen in aging), E2 stimulation of nNOS may lack vascular benefits in aging. Small mesenteric arteries were isolated from female Sprague Dawley rats, 3 or 12 months old, who were ovariectomized (Ovx) and treated with placebo or E2 for 4 wk. Vascular relaxation to exogenous E2 (0.001-100 μmol/liter) ± selective nNOS inhibitor (N-propyl-l-arginine, 2 μmol/liter) or pan-NOS inhibitor [Nω-nitro-l-arginine methyl ester (l-NAME), 100 μmol/liter] was examined on wire myograph. NOS expression was measured by Western blotting in thoracic aortas, in which superoxide generation was detected as dihydroethidium (DHE) fluorescence. E2 relaxations were impaired in Ovx conditions. E2 treatment (4 wk) normalized vascular function in young rats only. Both l-N-propyl-l-arginine and l-NAME blunted E2 relaxation in young controls, but only l-NAME did so in aging controls. NOS inhibition had no effect on acute E2 relaxation in Ovx rats, regardless of age or treatment. nNOS expression was similar in all animal groups. However, nNOS inhibition increased DHE fluorescence in young controls, whereas it reduced it in aging or Ovx animals. In E2-treated animals of either age, superoxide production was NOS independent. In conclusion, nNOS contributed to vascular relaxation in young, but not aging rats, where its enzymatic function shifted toward superoxide production. Thus, nNOS dysfunction may explain a mechanism of impaired E2 signaling in aging conditions.

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