Comparison of Plasma Profiles of Oxytocin and Prolactin following Suckling in the Rat

Grosvenor, Clark E.; Shyr, S. W.; Goodman, Gordon T.; Mena, Flavio

doi:10.1159/000124604

Cited by 50 publications

(25 citation statements)

References 18 publications

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“…This stimulatory dopami nergic mechanism may interact with the previously identified a-noradrenergic system [ 1,[3][4][5] as a component of the suckling-induced neuroendocrine reflex evoking OT release. In view of the complexities that are now recognized in the pattern of OT release in the lactating rat, such as long latencies until release of the hormone following pup reattachment, and the multiplicity of brief release episodes [19,[21][22][23][24][25], it seems likely that the ac tivity in multiple neural systems may be affected by suckling to induce release of OT.…”

Section: Discussionmentioning

confidence: 99%

“…Litters were culled to 8 on the second or third day after parturition. Between days 9 -14 o f lactation, rats were anesthetized with ether and implanted with a chronically in dwelling intraatriai cannula, as described previously [ 19]. NILS were electrically stimulated using a pair o f teflon-insulated, platinum-iridium wires (0.005 inch) glued flat to the filter paper.…”

Section: Animalsmentioning

confidence: 99%

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Excitatory and Inhibitory Dopaminergic Regulation of Oxytocin Secretion in the Lactating Rat: Evidence for Respective Mediation by D-1 and D-2 Dopamine Receptor Subtypes

Crowley¹,

Parker²,

Armstrong

et al. 1991

Neuroendocrinology

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The present experiments were designed to test whether the previously reported excitatory and inhibitory effects of dopamine (DA) on the secretion of oxytocin (OT) in lactating rats are exerted at different DA receptor subtypes, and to examine whether one or both of these effects might occur at the level of the posterior pituitary. The basal release of OT in nonsuckled, lactating rats was increased after intravenous administration of the D-1 DA agonist SKF 38393, and this effect, as well as the suckling-induced release of OT, was prevented by treatment with the D-1 DA antagonist SCH 23390, suggesting that DA may exert an important stimulatory influence over OT secretion through an action at the the D-1 DA receptor subtype. A small stimulation of basal PRL release was also produced by SKF 38393, but blockade of the D-1 DA receptor did not prevent the suckling-induced release of this hormone. Stimulation of the D-2 DA receptor with PPHThad no effect on basal OT release in nonsuckled rats, but this agent, as well as another D-2 DA agonist, bromocriptine, prevented the suckling-induced release of both OT and PRL. The inhibitory effect of D-2 DA receptor stimulation was blocked by the D-2 DA antagonist domperidone, which increased the basal release of both hormones when given alone. These observations confirm previous findings that inhibitory effects of DA on suckling-induced OT release are mediated through activation of the D-2 DA receptor. To test whether either dopaminergic effect occurs at the level of neurosecretory endings in the neurointermediate lobe (), the stalk- was isolated from lactating rats and perifused in vitro. The stalk- junction was electrically stimulated for 4 s, and the effects of selective D-1 DA and D-2 DA agonists and antagonists on the basal and electrically evoked release of OT and vasopressin (VP) was assessed using the two stimulation (S₂/S₁) paradigm. Electrical stimulation produced marked increases in release of both neural lobe peptides in a Ca²⁺-dependent manner, and the electrically evoked release of OT, but not VP, was enhanced by the opiate antagonist naltrexone (10 µM). Consistent with the in vivo results, SKF-38393 (20 µM) produced a small, but statistically significant, increase in electrically induced OT release, while SCH 23390 (20 µM) was without significant effect. Neither drug affected the basal release of OT or the basal or electrically stimulated release of VP. Neither bromocriptine nor domperidone (each 10 µM) affected the basal or electrically evoked release of OT or VP from perifused . These results indicate that DA exerts an excitatory effect on OT release, mediated by the D-1 DA receptor, which may be important for the stimulation of OT release by suckling, and which may occur, in part, at the level of the neural lobe. In contrast, the inhibitory influence of DA on OT release is exerted at the D-2 DA receptor, but this effect does not appear to be exerted at the level of the neural lobe.

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Section: Discussionmentioning

confidence: 99%

Section: Animalsmentioning

confidence: 99%

Excitatory and Inhibitory Dopaminergic Regulation of Oxytocin Secretion in the Lactating Rat: Evidence for Respective Mediation by D-1 and D-2 Dopamine Receptor Subtypes

Crowley¹,

Parker²,

Armstrong

et al. 1991

Neuroendocrinology

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“…Furthermore, the increase in hypothalamic NPY and AgRP expression and decrease in circulating leptin are dependent on the suckling stimulus of pups (Brogan et al, 1999;Li et al, 1998). Given that suckling behavior induces release of prolactin and oxytocin in the maternal brain (Grosvenor et al, 1986), this suggests a potential modulatory role of prolactin and oxytocin on expression of feeding-related peptides. Our knowledge of the neural correlates of lactation in rodents is making great strides, but many questions remain, such as how hyperphagia is mediated in the brain in a way that prevents eating offspring, if the peptides involved in lactation alter other maternal behaviors; how facilitation of feeding and maternal care occurs at the neural circuit level; and how these findings translate to nonrodent mammals.…”

Section: Offspring Provisioning and Increased Feeding Behaviormentioning

confidence: 99%

Modification of feeding circuits in the evolution of social behavior

Fischer

O’Connell

2017

Journal of Experimental Biology

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Adaptive trade-offs between foraging and social behavior intuitively explain many aspects of individual decision-making. Given the intimate connection between social behavior and feeding/foraging at the behavioral level, we propose that social behaviors are linked to foraging on a mechanistic level, and that modifications of feeding circuits are crucial in the evolution of complex social behaviors. In this Review, we first highlight the overlap between mechanisms underlying foraging and parental care and then expand this argument to consider the manipulation of feeding-related pathways in the evolution of other complex social behaviors. We include examples from diverse taxa to highlight that the independent evolution of complex social behaviors is a variation on the theme of feeding circuit modification.

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“…The PRL magnitude correlates with the number of suckling pups and the duration of suckling. Adapted, with permission, from Grosvenor CE, Shyr SW, Goodman GT & Mena F 1986 Comparison of plasma profiles of oxytocin and prolactin following suckling in the rat. Neuroendocrinology 43 679-685. q 1986 S. Karger AG, Basel.…”

Section: Secretory Rhythms Of Pituitary Hormonesmentioning

confidence: 99%

Prolactin secretion patterns: basic mechanisms and clinical implications for reproduction

Egli¹,

Leeners²,

Krüger³

2010

Reproduction

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Prolactin (PRL) is one of the most versatile hormones in the mammalian body affecting reproductive, sexual, metabolic, immune, and other functions. It is therefore not surprising that the neural control of PRL secretion is complex, involving the coordinated actions of several hypothalamic nuclei. A plethora of experimental data exists on the hypothalamic control of hormone secretion under various physiological stimuli. There have been even mathematical models and computer studies published, which help to understand the complex hypothalamic-pituitary network. Nevertheless, the putative role of PRL for human reproduction still has to be clarified. Here, we review data on the underlying mechanisms controlling PRL secretion using both experimental and mathematical approaches. These investigations primarily focus on rhythmic secretion in rats during early pregnancy or pseudopregnancy, and they point to the important role of oxytocin as a crucial PRL-releasing factor. Recent data on human studies and their theoretical and clinical implications are reviewed as well. In particular, studies demonstrating a sustained PRL surge after sexual climax in males and females are presented, indicating possible implications for both sexual satiation and reproductive functions. Taking these data together, there is evidence for the hypothesis that the PRL surge induced by sexual activity, together with the altered PRL rhythmic pattern, is important for successful initialization of pregnancy not only in rodents but also possibly in humans. However, further investigations are needed to clarify such a role in humans.

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Comparison of Plasma Profiles of Oxytocin and Prolactin following Suckling in the Rat

Cited by 50 publications

References 18 publications

Excitatory and Inhibitory Dopaminergic Regulation of Oxytocin Secretion in the Lactating Rat: Evidence for Respective Mediation by D-1 and D-2 Dopamine Receptor Subtypes

Excitatory and Inhibitory Dopaminergic Regulation of Oxytocin Secretion in the Lactating Rat: Evidence for Respective Mediation by D-1 and D-2 Dopamine Receptor Subtypes

Modification of feeding circuits in the evolution of social behavior

Prolactin secretion patterns: basic mechanisms and clinical implications for reproduction

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