Ontogenic studies of the neural control of adenohypophyseal hormones in the rat. II. prolactin

Becú-Villalobos, Damasia; Lacau-Mengido, I.M.; Dı́az-Torga, Graciela; Libertun, Carlos

doi:10.1007/bf00711635

Cited by 23 publications

(12 citation statements)

References 141 publications

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“…In addition to PAE‐specific effects on E 2 and P 4 levels, we show that neither PAE nor PF females display age‐related increases in PRL levels, consistent with previous reports (Becu‐Villalobos et al., ). Our finding of reduced PRL levels in adult PAE females is in agreement with previous data (Hannigan et al., ).…”

Section: Discussionsupporting

confidence: 93%

Prenatal Alcohol Exposure and Pair Feeding Differentially Impact Puberty and Reproductive Development in Female Rats: Role of the Kisspeptin System

Śliwowska

Comeau

Bodnar

et al. 2016

Alcoholism Clin & Exp Res

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Background Reproductive maturation is initiated with the onset of puberty, which activates the hypothalamic-pituitary-gonadal axis and coincidences with increased expression of the hormone kisspeptin within the hypothalamus. Maturational events are sensitive to environmental factors, including alcohol, which is known to delay reproductive development. We hypothesized that, similar to alcohol's adverse effects during reproductive maturation, prenatal alcohol exposure (PAE) would alter pubertal markers, sex hormone profiles, and kisspeptin expression in the hypothalamus. Methods Female offspring from control (C), pair-fed (PF), and PAE groups were sacrificed prior to puberty onset (postnatal day [PND] 30), during puberty (PND 35), or in adulthood (PND 65). Estradiol (E2), progesterone (P4), prolactin (PRL) and luteinizing hormone (LH) levels, and Kiss1 mRNA expression were measured in the arcuate (ARC) and anteroventral periventricular (AVPV) nuclei of the hypothalamus. Pubertal markers (vaginal opening, uterus/body weight ratio) were assessed. Results Our findings indicate that: 1) PAE inhibits the expected increases in E2 levels with age and delays maturational increases of P4 levels; 2) PAE and pair-feeding have similar adverse effects on: i) vaginal opening and uterus/body weight ratio; 3) Differential relationships between PRL and P4 suggest that different mechanisms may underlie delayed maturation in PAE and PF; that is, PF females have low PRL levels and no increase in P4 with age, whereas PAE animals, despite low PRL, show the expected age-related increase in P4. 4) There is higher mean density of Kiss1 mRNA in the ARC of adult PAE females and altered Kiss1 expression in the AVPV of both PAE and PF females. Conclusions PAE and pair-feeding have some overlapping but important differential effects on hormonal profiles and Kiss1 mRNA expression during reproductive development. Pre-adolescent alterations in Kiss1 expression in the AVPV and ARC, which may change the balance of function in these two nuclei, may differentially contribute to delayed reproductive maturation in PAE and PF compared to C females.

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Section: Discussionsupporting

confidence: 93%

Prenatal Alcohol Exposure and Pair Feeding Differentially Impact Puberty and Reproductive Development in Female Rats: Role of the Kisspeptin System

Śliwowska

Comeau

Bodnar

et al. 2016

Alcoholism Clin & Exp Res

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“…The participation of the brain in controlling early events of the development of FSH, LH and PRL secretion, as well as on sexual development in mammals, is well documented (22,23). FSH secretion is high in immature female rats from Days 10 to 18, and decreases thereafter until adulthood.…”

Section: Discussionmentioning

confidence: 99%

-Difluoromethylornithine Modifies Gonadotropin-Releasing Hormone Release and Follicle-Stimulating Hormone Secretion in the Immature Female Rat

Thyssen

Becú-Villalobos

Lacau-Mengido

et al. 1997

Experimental Biology and Medicine

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Polyamines play an essential role in tissue growth and differentiation, in body weight increment, in brain organization, and in the molecular mechanisms of hormonal action, intracellular signaling, and cell-to-cell communication. In a previous study, inhibition of their synthesis by alpha-difluoromethylornithine (DFMO), a specific and irreversible inhibitor of ornithine decarboxylase, during development in female rats, was followed by prolonged high follicle-stimulating hormone (FSH) serum level and a delayed puberty onset. Those changes were relatively independent of body mass and did not impair posterior fertility. The present work studies the mechanisms and site of action of polyamine participation in FSH secretion during development. DFMO was injected in female rats between Days 1 and 9 on alternate days. At 10 days of age, hypothalami from control and DFMO rats were perifused in vitro, and basal and potassium-induced gonadotropin-releasing hormone (GnRH) release were measured. The response to membrane depolarization was altered in DFMO hypothalami. Increased GnRH release in response to a low K+ concentration was evidenced. Adenohypophyses of the same treated prepubertal rats were perifused in vitro and the response to GnRH pulses was checked. In DFMO-treated rats, higher FSH release was observed, with no changes in LH or PRL secretion. Finally, pituitary GnRH receptor number in adenohypophyseal membranes from treated and control groups was quantified. A significant reduction in specific binding was evident in hypophyses from DFMO-treated rats when compared with binding in the control group. In summary, DFMO treatment in a critical developmental period in the female rat impacts the immature GnRH neuronal network and immature gonadotropes. A delay in maturation is evidenced by a higher sensitivity to secretagogs in both pituitary glands and hypothalamic explants. These events could explain the prolonged high FSH serum levels and delayed puberty onset seen in this experimental model.

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“…The fact that the prolactin-releasing effect of All increases with age, even in the presence of an increasing dopaminergic inhibition [34,35], suggests that the greater action of prolactin-releasing factors, such as serotonin, estradiol [40] and All, during development may account for the increase in prolactin levels that is evidenced dur ing the juvenile and prepubertal periods [41]. It has been postulated that the endogenous brain All system appears not to be involved in the maintenance of low plasma pro lactin levels observed under basal unstressed conditions.…”

Section: Discussionmentioning

confidence: 99%

Ontogeny of Angiotensin-II-Induced Prolactin Release in vivo and in vitro in Female and Male Rats

Dı́az-Torga

Becú-Villalobos²,

Libertun³

1994

Neuroendocrinology

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The prolactin-releasing effect of angiotensin II (AII) was studied in the developing female and male rat in vivo and in vitro. AII (50 and 100 µg/100 g b.w.) was injected intraperitoneally to female and male rats aged 4, 12, 20 and 28 days and males aged 38 days. AII (10^–6M) was also tested in pituitaries incubated in vitro from animals of both sexes aged 12, 20 and 28 days. In addition, as two subtypes of AII receptors have been characterized on the basis of displacement with specific AII antagonists, we used the nonpeptide AII receptor antagonists losartan (ATI subtype) and PD 123319 (AT2 subtype) to determine the AII receptor subtype functionally involved in AII-induced prolactin secretion in vivo in 25-day-old male rats. The efficiency of the prolactin-releasing effect of AII in vivo increased with age, and first responses were observed at 20 days of age in both sexes. No sexual differences were encountered. On the other hand, AII-induced prolactin release from pituitaries incubated in vitro was first demonstrated at 12 days in females and at 20 days in males. The effect increased with age in both sexes, and, at 28 days, pituitaries from females released more prolactin in response to AII than those from males. Losartan (3 mg/kg) completely abolished AII (50µg/100g b.w.)-induced prolactin release in vivo, while PD 123319 (3 mg/kg) did not. This suggests that pituitary ATI receptors are functionally involved in the prolactin release induced by AII in vivo. In vivo, the integrity of the hypothalamic-hypophyseal unit is maintained, and therefore the inhibitory influence of the dopaminergic system, which is stronger in the female developing rat, could mask the sexual differences encountered in vitro. Finally, increasing efficiency of AII-induced prolactin release may be related to increasing prolactin titers in juvenile and prepubertal rats.

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Ontogenic studies of the neural control of adenohypophyseal hormones in the rat. II. prolactin

Cited by 23 publications

References 141 publications

Prenatal Alcohol Exposure and Pair Feeding Differentially Impact Puberty and Reproductive Development in Female Rats: Role of the Kisspeptin System

Prenatal Alcohol Exposure and Pair Feeding Differentially Impact Puberty and Reproductive Development in Female Rats: Role of the Kisspeptin System

-Difluoromethylornithine Modifies Gonadotropin-Releasing Hormone Release and Follicle-Stimulating Hormone Secretion in the Immature Female Rat

Ontogeny of Angiotensin-II-Induced Prolactin Release in vivo and in vitro in Female and Male Rats

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