scholarly journals Nitric oxide sensitive-guanylyl cyclase subunit expression changes during estrous cycle in anterior pituitary glands

2009 ◽  
Vol 296 (4) ◽  
pp. E731-E737 ◽  
Author(s):  
Jimena P. Cabilla ◽  
Sonia A. Ronchetti ◽  
Silvana I. Nudler ◽  
Eliana A. Miler ◽  
Fernanda A. Quinteros ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Pituitary Gland ◽  
Estrous Cycle ◽  
Guanylyl Cyclase ◽  
Anterior Pituitary ◽  
Acute Treatment ◽  
Α Subunit ◽  
Immature Rats ◽  
Subunit Expression ◽  
Pituitary Glands

17β-Estradiol (E2) exerts inhibitory actions on the nitric oxide pathway in rat adult pituitary glands. Previously, we reported that in vivo E2 acute treatment had opposite effects on soluble guanylyl cyclase (sGC) subunits, increasing α1- and decreasing β1-subunit protein and mRNA expression and decreasing sGC activity in immature rats. Here we studied the E2 effect on sGC protein and mRNA expression in anterior pituitary gland from adult female rats to address whether the maturation of the hypothalamus-pituitary axis influences its effects and to corroborate whether these effects occur in physiological conditions such as during estrous cycle. E2 administration causes the same effect on sGC as seen in immature rats, and these effects are estrogen receptor dependent. These results suggest that E2 is the main effector of these changes. Since the sGC α-subunit increases while the sGC activity decreases, we studied if other less active isoforms of the sGC α-subunit are expressed. Here we show for the first time that sGCα2 and sGCα2 inhibitory (α2i) isoforms are expressed in this gland, but only sGCα2i mRNA increased after E2 acute treatment. Finally, to test whether E2 effects take place under a physiological condition, sGC subunit expression was monitored over estrous cycle. sGCα1, -β1, and -α2i fluctuate along estrous cycle, and these changes are directly related with E2 level fluctuations rather than to NO level variations. These findings show that E2 physiologically regulates sGC expression and highlight a novel mechanism by which E2 downregulates sGC activity in rat anterior pituitary gland.

scholarly journals 17β-Estradiol Modifies Nitric Oxide-Sensitive Guanylyl Cyclase Expression and Down-Regulates Its Activity in Rat Anterior Pituitary Gland

Endocrinology ◽  
2006 ◽  
Vol 147 (9) ◽  
pp. 4311-4318 ◽  
Author(s):  
Jimena P. Cabilla ◽  
María del Carmen Díaz ◽  
Leticia I. Machiavelli ◽  
Ariel H. Poliandri ◽  
Fernanda A. Quinteros ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Pituitary Gland ◽  
Mrna Expression ◽  
Guanylyl Cyclase ◽  
Anterior Pituitary ◽  
Acute Treatment ◽  
Inhibitory Effect ◽  
Anterior Pituitary Gland ◽  
Cgmp Pathway ◽  
17Β Estradiol

Previous studies showed that 17β-estradiol (17β-E2) regulates the nitric oxide (NO)/soluble guanylyl cyclase (sGC)/cGMP pathway in many tissues. Evidence from our laboratory indicates that 17β-E2 disrupts the inhibitory effect of NO on prolactin release, decreasing sGC activity and affecting the cGMP pathway in anterior pituitary gland of adult ovariectomized and estrogenized rats. To ascertain the mechanisms by which 17β-E2 affects sGC activity, we investigated the in vivo and in vitro effects of 17β-E2 on sGC protein and mRNA expression in anterior pituitary gland from immature female rats. In the present work, we showed that 17β-E2 acute treatment exerted opposite effects on the two sGC subunits, increasing α1 and decreasing β1 subunit protein and mRNA expression. This action on sGC protein expression was maximal 6–9 h after 17β-E2 administration. 17β-E2 also caused the same effect on mRNA expression at earlier times. Concomitantly, 17β-E2 dramatically decreased sGC activity 6 and 9 h after injection. These effects were specific of 17β-E2, because they were not observed with the administration of other steroids such as progesterone and 17α-estradiol. This inhibitory action of 17β-E2 on sGC also required the activation of estrogen receptor (ER), because treatment with the pure ER antagonist ICI 182,780 completely blocked 17β-E2 action. 17β-E2 acute treatment caused the same effects on pituitary cells in culture. These results suggest that 17β-E2 exerts an acute inhibitory effect on sGC in anterior pituitary gland by down-regulating sGC β1 subunit and sGC activity in a specific, ER-dependent manner.

Nitric Oxide-Sensitive Guanylyl Cyclase α1- and β1-Subunits Are Differentially Regulated by Classical and Non-Classical Estrogen Pathways in Anterior Pituitary Gland

2011 ◽  
pp. P3-22-P3-22
Author(s):  
Jimena Paula Cabilla ◽  
Sonia Alejandra Ronchetti ◽  
Silvana Iris Nudler ◽  
Fernanda Alnilan Quinteros ◽  
Beatriz Haydee Duvilanski
Keyword(s):  
Nitric Oxide ◽  
Pituitary Gland ◽  
Guanylyl Cyclase ◽  
Anterior Pituitary ◽  
Anterior Pituitary Gland

scholarly journals Nitric Oxide-Sensitive Guanylyl Cyclase Is Differentially Regulated by Nuclear and Non-Nuclear Estrogen Pathways in Anterior Pituitary Gland

PLoS ONE ◽  
2011 ◽  
Vol 6 (12) ◽  
pp. e29402 ◽  
Author(s):  
Jimena P. Cabilla ◽  
Silvana I. Nudler ◽  
Sonia A. Ronchetti ◽  
Fernanda A. Quinteros ◽  
Mercedes Lasaga ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Pituitary Gland ◽  
Guanylyl Cyclase ◽  
Anterior Pituitary ◽  
Anterior Pituitary Gland

Posttranscriptional regulation of rat growth hormone gene expression: increased message stability and nuclear polyadenylation accompany thyroid hormone depletion

1992 ◽  
Vol 12 (6) ◽  
pp. 2624-2632
Author(s):  
D Murphy ◽  
K Pardy ◽  
V Seah ◽  
D Carter
Keyword(s):  
Growth Hormone ◽  
Thyroid Hormone ◽  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Posttranscriptional Regulation ◽  
Anterior Pituitary Gland ◽  
Growth Hormone Gene ◽  
Gh Gene ◽  
Rat Growth ◽  
Pituitary Glands

In thyroid hormone-depleted rats, the rate of transcription of the growth hormone (GH) gene in the anterior pituitary gland is lower than the rate in euthyroid controls, and there is a corresponding reduction in the abundance of the GH mRNA. Concomitantly, the poly(A) tail of the GH mRNA increases in length. Examination of nuclear RNA from anterior pituitary glands of control and thyroid hormone-depleted rats revealed no difference in the length of pre-mRNAs containing the first and last introns of the GH gene. However, mature nuclear GH RNA is differentially polyadenylated in euthyroid and hypothyroid animals. We suggest that the extent of polyadenylation of the GH transcript is regulated in the cell nucleus concomitant with or subsequent to the splicing of the pre-mRNA. Experiments with anterior pituitary gland explant cultures demonstrated that the GH mRNA from thyroid hormone-depleted rats is more stable than its euthyroid counterpart and that the poly(A) tail may contribute to the differential stability of free GH ribonucleoproteins.

scholarly journals Gonadotrope Plasticity at Cellular and Population Levels

Endocrinology ◽  
2012 ◽  
Vol 153 (10) ◽  
pp. 4729-4739 ◽  
Author(s):  
Zahara Alim ◽  
Cheryl Hartshorn ◽  
Oliver Mai ◽  
Iain Stitt ◽  
Colin Clay ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Ex Vivo ◽  
Single Cells ◽  
Anterior Pituitary Gland ◽  
Female Mice ◽  
Model Animal ◽  
Pituitary Glands ◽  
Acute Changes

Abstract Hormone-secreting cells within the anterior pituitary gland may form organized and interdigitated networks that adapt to changing endocrine conditions in different physiological contexts. For gonadotropes, this might reflect a strategy to cope with acute changes throughout different female reproductive stages. The current study examined gonadotropes in female mice at characteristically different hormonal stages: prepubertal, postpubertal, and lactating. Gonadotrope plasticity was examined at the level of the whole population and single cells at different stages by imaging both fixed and live pituitary slices. The use of a model animal providing for the identification of selectively fluorescent gonadotropes allowed the particular advantage of defining cellular plasticity specifically for gonadotropes. In vivo analyses of gonadotropes relative to vasculature showed significantly different gonadotrope distributions across physiological states. Video microscopy studies using live slices ex vivo demonstrated pituitary cell plasticity in the form of movements and protrusions in response to GnRH. As positive feedback from rising estradiol levels is important for priming the anterior pituitary gland for the LH surge, experiments provide evidence of estradiol effects on GnRH signaling in gonadotropes. The experiments presented herein provide new insight into potential plasticity of gonadotropes within the anterior pituitary glands of female mice.

scholarly journals Diabetes and Hypercholesterolemia Impair the Cytological Structure of the Anterior Pituitary Gland

2019 ◽  
Vol 16 (3) ◽  
pp. 649-658
Author(s):  
Ahmed MR Abdo ◽  
Mohamed E El-Beeh ◽  
Sameer H. Qari ◽  
Dina A El-badry ◽  
Hassan IH El-Sayyad
Keyword(s):  
Body Weight ◽  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Secretory Granules ◽  
Reproductive Function ◽  
Anterior Lobe ◽  
Anterior Pituitary Gland ◽  
Albino Rats ◽  
Pituitary Glands ◽  
Cytological Picture

Increase consumption of high fat diet was found to alter blood sugar level similar to diabetes and contributed to the development of obesity and affected the reproductive function of both sexes. The study aimed to clarify the influence of diabetes and or hypercholesterolemia on the cytological picture of cells of the anterior lobe of pituitary gland of male albino rats. Eighteen male albino rats weighing approximately 120 gram body weight were divided into three main groups; control, diabetes, hypercholesterolemia, diabetes (single i.p. 40 mg streptozotocin/kg B.wt plus 100mg. nicotinamide /kg body weight) and hypercholesterolemia (diet containing 3% cholesterol). Dietary feeding on cholesterol and diabetes were carried out for 12 weeks. At the end of treatment, animals were sacrificed, and pituitary glands were separated and their anterior lobe was processed for cytological investigations by transmission electron microscopy. The present study revealed that the rats subjected to experimental diabetes and/ or hypercholesterolemia exhibited a decrease of the secretory granules within the gonadotroph cells somatotroph and corticotrophin cells. There was a detected intracellular accumulation of fat globules in both the gonado- and sommatotroph cells. The authors reported that the altered cytological structures of the secretory function of the anterior pituitary gland led to marked impairment of the male hormonal level and causing infertility.

Multiple species of follicle-stimulating hormone exist within the anterior pituitary gland of male golden hamsters

1982 ◽  
Vol 95 (2) ◽  
pp. 257-266 ◽  
Author(s):  
Alfredo Ulloa-Aguirre ◽  
S. C. Chappel
Keyword(s):  
Pituitary Gland ◽  
Isoelectric Point ◽  
Receptor Binding ◽  
Anterior Pituitary ◽  
Hormone Secretion ◽  
Anterior Pituitary Gland ◽  
Con A ◽  
Pituitary Glands ◽  
Multiple Species ◽  
Gel Isoelectric Focusing

Anterior pituitary glands were collected from immature and mature (intact and castrated) male hamsters. The various species of FSH present within these glands were separated by Concanavalin A (Con A) chromatography and polyacrylamide gel isoelectric focusing (PAG-IEF) and measured by a specific FSH radioimmunoassay (RIA) as well as a radioreceptor assay (RRA). Two distinct forms of FSH (Con A unbound and bound) were separated by Con A chromatography and detected by both RIA and RRA. These two populations of FSH were present within anterior pituitary glands of all three animal models tested. Castration before collection of anterior pituitary glands reduced the ratio of Con A unbound: bound immunoreactive FSH. When measured by RRA this reduction was not observed. When homogenates of anterior pituitary glands obtained from mature animals were separated by PAG-IEF, six distinct species of FSH were observed by RIA with isoelectric points (pI) of 6·0, 5·7, 5·3, 5·0, 4·7 and 4·2–3·8. Homogenates of anterior pituitary glands obtained from immature male hamsters did not contain one of these species of FSH (pI value, 4·7). The relative contribution of some of the species of FSH to the total amount of detectable FSH differed depending upon the endocrine status of the animal. The species with pI value of 4·2–3·8 did not show any receptor-binding activity in any of the three models studied. The overall ratio of the activity of FSH measured by RRA compared with RIA was highest in anterior pituitary glands from intact mature and immature hamsters and lowest in anterior pituitary glands obtained from castrated animals. The RRA: RIA ratio for each species of FSH in all models tested declined as the isoelectric point of that species decreased. Thus, these results demonstrated the presence of multiple species of FSH within the anterior pituitary glands of immature and mature male hamsters. The relative proportions and receptor-binding activities of these species differed according to the isoelectric point and the pattern of hormone secretion at the time of collection of pituitary glands. Gonadal and other endocrine factors may influence not only the relative amount of each species of FSH but also the receptor-binding capacity of the FSH species synthesized by the anterior pituitary gland.

Relationships among release of prolactin, synthesis of DNA and growth of the anterior pituitary gland of the rat: effects of oestrogen and sulpiride

1982 ◽  
Vol 94 (1) ◽  
pp. 1-10 ◽  
Author(s):  
G. A. Jahn ◽  
G. A. Machiavelli ◽  
L. E. Kalbermann ◽  
I. Szijan ◽  
G. E. Alonso ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Single Injection ◽  
Serum Levels ◽  
Anterior Pituitary Gland ◽  
Male Rats ◽  
Maximum Increase ◽  
End Of Treatment ◽  
Pituitary Glands ◽  
Prolactin Synthesis

The effect of daily injections of sulpiride was compared with that of a single injection of the drug in male rats which had been treated with oestradiol diundecenoate for various periods of time. We studied the effect of the different treatments on weight of the pituitary gland, concentration of prolactin and incorporation of [3H]thymidine into DNA in the pituitary gland and on serum levels of prolactin. Administration of the oestrogen produced a marked increase in the synthesis of DNA at day 7. The stimulation diminished at day 21 and was not significant at day 45. The maximum increase in the concentration of prolactin in serum and pituitary glands was observed during the first 7 days (approximately 400 and 150% respectively) and in the weight of the anterior pituitary gland after 21 days of treatment (approximately 107%). A single injection of sulpiride markedly stimulated the release of prolactin and the synthesis of DNA at day 7. Both these effects diminished at day 21 and disappeared by day 45. Daily injections of sulpiride also produced similar changes in the release of prolactin and in the replication of DNA. The growth of the anterior pituitary gland was greater in this group than in the rats which had been treated with oestradiol diundecenoate only. After the end of treatment with oestrogen and sulpiride the pituitary weight and the concentration of prolactin in the anterior pituitary gland diminished together with levels of prolactin and oestrogen in serum. There was a good correlation between weight of the gland and serum levels of prolactin. The results further support the idea of a mechanism which controls the proliferation of lactotrophs in which the release of the hormone is accompanied by an increase in pituitary DNA synthesis.

Prolactin promotes oxytocin and vasopressin release by activating neuronal nitric oxide synthase in the supraoptic and paraventricular nuclei

2010 ◽  
Vol 299 (6) ◽  
pp. R1701-R1708 ◽  
Author(s):  
Claudia Vega ◽  
Bibiana Moreno-Carranza ◽  
Miriam Zamorano ◽  
Andrés Quintanar-Stéphano ◽  
Isabel Méndez ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Anterior Pituitary ◽  
Neuronal Nitric Oxide Synthase ◽  
Male Rats ◽  
Female Reproduction ◽  
Vasopressin Release ◽  
Hypothalamic Nuclei ◽  
Pituitary Glands ◽  
Oxide Synthase

Prolactin (PRL) stimulates the secretion of oxytocin (OXT) and arginine AVP as part of the maternal adaptations facilitating parturition and lactation. Both neurohormones are under the regulation of nitric oxide. Here, we investigate whether the activation of neuronal nitric oxide synthase (nNOS) in the hypothalamo-neurohypophyseal system mediates the effect of PRL on OXT and AVP release and whether these effects operate in males. Plasma levels of OXT and AVP were measured in male rats after the intracerebroventricular injection of PRL or after inducing hyperprolactinemia by placing two anterior pituitary glands under the kidney capsule. NOS activity was evaluated in the paraventricular (PVN) and supraoptic (SON) hypothalamic nuclei by NADPH-diaphorase histochemistry and in hypothalamic extracts by the phosphorylation/inactivation of nNOS at Ser847. Elevated central and systemic PRL correlated with increased NOS activity in the PVN and SON and with higher OXT and AVP circulating levels. Notably, treatment with 7-nitroindazole, a selective inhibitor of nNOS, prevented PRL-induced stimulation of the release of both neurohormones. Also, phosphorylation of nNOS was reduced in hyperprolactinemic rats, and treatment with bromocriptine, an inhibitor of anterior pituitary PRL secretion, suppressed this effect. These findings suggest that PRL enhances nNOS activity in the PVN and SON, thereby contributing to the regulation of OXT and AVP release. This mechanism likely contributes to the regulation of processes beyond those of female reproduction.

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