Pulsatile prolactin secretory patterns throughout the oestrous cycle in the rat

Lafuente, A.; Marcó, J; Esquifino, A.

doi:10.1677/joe.0.1370043

Cited by 14 publications

(11 citation statements)

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“…In humans and rats, pituitary prolactin release is both pulsatile and nyctohemeral [1][2][3][4]. Also, in female dogs, a pulsatile secretion pattern for prolactin has been demonstrated [5], while in male dogs a pulsatile secretion of this hormone is only suggested considering spontaneously elevated prolactin concentrations found in individual but not all dogs [6].…”

Section: Introductionmentioning

confidence: 99%

Effects of the dopamine agonist cabergoline on the pulsatile and TRH-induced secretion of prolactin, LH, and testosterone in male beagle dogs

Koch

Hoppen²,

Dieleman

et al. 2006

Theriogenology

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In the present study, the pulsatile serum profiles of prolactin, LH and testosterone were investigated in eight clinically healthy fertile male beagles of one to six years of age. Serum hormone concentrations were determined in blood samples collected at 15 min intervals over a period of 6 h before (control) and six days before the end of a four weeks treatment with the dopamine agonist cabergoline (5 mg kg À1 bodyweight/day). In addition, the effect of cabergoline administration was investigated on thyrotropin-releasing hormone (TRH)-induced changes in the serum concentrations of these hormones.In all eight dogs, the serum prolactin concentrations (mean 3.0 AE 0.3 ng ml À1 ) were on a relatively constant level not showing any pulsatility, while the secretion patterns of LH and testosterone were characterised by several hormone pulses. Cabergoline administration caused a minor but significant reduction of the mean prolactin concentration (2.9 AE 0.2 ng ml À1 , p < 0.05) and did not affect the secretion of LH (mean 4.6 AE 1.3 ng ml À1 versus 4.4 AE 1.7 ng ml À1 ) or testosterone (2.5 AE 0.9 ng ml À1 versus 2.4 AE 1.2 ng ml À1 ). Under control conditions, a significant prolactin release was induced by intravenous TRH administration (before TRH: 3.8 AE 0.9 ng ml À1 ,

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Section: Introductionmentioning

confidence: 99%

Effects of the dopamine agonist cabergoline on the pulsatile and TRH-induced secretion of prolactin, LH, and testosterone in male beagle dogs

Koch

Hoppen²,

Dieleman

et al. 2006

Theriogenology

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“…All those studies were performed in the so called basal conditions, although prolactin, like other pituitary hormones, is secreted following a ultradian episodic pattern (Lafuente et al, 1993(Lafuente et al, , 1994. Thus an effect of NO on this mechanism could be foreseen.…”

Section: Introductionmentioning

confidence: 99%

Effect of nitric oxide on prolactin secretion and hypothalamic biogenic amine contents

et al. 2004

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“…I m l/100 g body weight) and atrial cannulas were implanted through the external jugular vein according to procedures used in previous studies [11,14], This procedure allows the animals to move freely in their cages during the period of bleeding.…”

Section: Cannula Implantationmentioning

confidence: 99%

“…Hyperprolactinemia was associated with diminished, unchanged or increased plasma LH levels [9]. Prolactin and/or LH are released in an episodic fash ion [10][11][12][13] that can be modified by hyperprolactinemia [14] through mechanisms which are not fully under stood. Previous studies showed that prolactin interferes with the pulsatile release of LHRH [15], thus modifying gonadal function.…”

Section: Introductionmentioning

confidence: 99%

Cyclosporine Modifies the Pulsatile Secretory Patterns of Prolactin and Luteinizing Hormone in Normal and Pituitary-Grafted Female Rats

Esquifino

Marcó²,

Lafuente³

1994

Neuroendocrinology

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This study was designed to examine whether cyclosporine (CyA) acts on the endocrine system by modifying the pulsatile secretion pattern of prolactin and LH. Both pituitary-grafted and sham-operated rats were submitted to a subcutaneous vehicle or CyA (5 mg/kg) treatment daily for 10 days beginning on the day of surgery. Pituitary grafting and/or CyA administration changed the pulsatile pattern of prolactin observed in sham-operated animals. The mean values of serum prolactin were significantly increased by pituitary grafting and the treatment with CyA further increased them. The mean half-life of prolactin was significantly increased in pituitary-grafted rats and was not changed by CyA administration, although it was decreased in sham-operated rats. The frequency of prolactin pulses was significantly decreased in pituitary-grafted as compared to sham-operated controls and was not further modified by CyA administration. However, in sham-operated rats a significant decrease of this parameter was observed. Duration of the prolactin peaks was significantly increased by pituitary grafting, and was not modified by CyA administration in any of the groups studied. The absolute amplitude of the prolactin peaks was significantly increased in pituitary-grafted as compared to sham-operated animals, and the treatment with CyA further increased this parameter in both groups. Mean values of LH were significantly increased in pituitary-grafted as compared to control rats. CyA administration significantly increased LH levels in sham-operated rats and decreased them in pituitary-grafted animals. The mean half-life, the pulse frequency and the duration of LH peaks were not modified by either pituitary grafting or CyA administration. The absolute amplitude of LH peaks was significantly increased in pituitary-grafted animals as compared to the sham-operated group. Cy administration increased the absolute amplitude of LH peaks in sham-operated and reduced it in pituitary-grafted animals. The data suggest that CyA might act by modifying the pulsatile secretory patterns of prolactin and LH.

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Pulsatile prolactin secretory patterns throughout the oestrous cycle in the rat

Cited by 14 publications

References 0 publications

Effects of the dopamine agonist cabergoline on the pulsatile and TRH-induced secretion of prolactin, LH, and testosterone in male beagle dogs

Effects of the dopamine agonist cabergoline on the pulsatile and TRH-induced secretion of prolactin, LH, and testosterone in male beagle dogs

Effect of nitric oxide on prolactin secretion and hypothalamic biogenic amine contents

Cyclosporine Modifies the Pulsatile Secretory Patterns of Prolactin and Luteinizing Hormone in Normal and Pituitary-Grafted Female Rats

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