Progesterone-Induced Luteinizing Hormone Release in Oestrogen-Primed Ovariectomized Rats After Destruction of Mid-Brain Inputs to Suprachiasmatic Nuclei

Barofsky, Anna-Lisa

doi:10.1677/joe.0.0660285

Cited by 11 publications

(6 citation statements)

References 5 publications

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“…Similarly, stimulation of the dorsal raphe nucleus inhibited ovulation (386) and ovarian steroid-induced LH secretion (387). On the other hand, drastic reduction of hypothalamic 5-HT levels on a chronic basis attenuated the estrogen-induced LH surge (388), but appropriate supplementation with P overcame the 5-HT deficiency and elicited a normal LH surge (387,389). In general, although there is considerable evidence in support of a facilitory role of 5-HT, the nature of 5-HT participation in preovulatory LH release remains to be determined especially in view of the fact that pharmacological agents which modify 5-HT levels also concurrently affect hypothalamic E concentrations (390).…”

Section: Neural Components Of the Nc On Proestrusmentioning

confidence: 99%

Neural Regulation of Luteinizing Hormone Secretion in the Rat*

1983

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Section: Neural Components Of the Nc On Proestrusmentioning

confidence: 99%

Neural Regulation of Luteinizing Hormone Secretion in the Rat*

1983

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“…Carrer and Taleisnik [12] reported that electrolytic stimulation of the MR nucleus prior to the critical period on proestrus blocked ovulation in normal cycling rats. Barofsky [5] has shown that electrolytic destruction of the MR nu cleus did not alter the estrogen-progesterone induced LH surge in ovariectomized rats. On the other hand, Meyer [36] has demonstrated that destruction of the MR or DR nucleus by local neurotoxin injection inhibited gonado tropin-induced ovulation, suggesting a facilitatory raphe input.…”

mentioning

confidence: 99%

Median Raphe Stimulation and Sham Procedures Inhibit the LH Surge

Al¹

1979

Neuroendocrinology

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Acute electrolytic stimulation of the median raphe (MR) nucleus (MR Stim) between 13:00 and 16:00 h on proestrus blocked ovulation in 10 of the 21 rats tested, whereas all sham-treated (MR Sham, no current) animals ovulated normally (n = 12). MR Stim at 16:00 h on proestrus in individual cannulated rats ‘turned off’ the luteinizing hormone (LH) surge in all animals tested. Unexpectedly, MR Sham treatment also abruptly inhibited the LH surge, although all animals ovulated. Manipulations associated with acute surgical procedures (puncture of the dura mater, ether anesthesia alone) were also found to inhibit the LH surge, with the magnitude of LH inhibition directly related to the severity of the operative procedures performed (p< 0.025). The results suggest (1) that inhibition of ovulation following MR stimulation can be attributed to a response to stress qualitatively similar but more severe than that experienced by the MR sham group, and (2) that inhibitory inputs to the ovulatory LH release mechanism cannot be studied using acute surgical procedures.

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“…The absence of the positive action of progesterone in animals with deafferentated MBH or with suprachiasmatic lesions (Taleisnik et al 1970;Barofsky, 1975) reinforces the idea that progesterone acts on the MBH lowering the threshold to stimuli coming from the POA or other extrahypothalamic structures involved in the control of LH. Docke & Dörner (1969) reported that systemic injection of progesterone reduces the MBH threshold to the electrical stimulation to induce ovulation.…”

Section: Preoptic Areamentioning

confidence: 56%

“…However, the effect depends upon the time of treatment with the hormone (Zeilmaker, 1966), an observation which is probably due to the multiple sites of action of steroids, which act directly at the level of the pituitary gland, as well as at several brain structures. Among these, the preoptic area (POA) and the medial basal hypothalamus (MBH) have been shown to be most important (Kordon & Bachrach, 1959; Barraclough, 1963;Everett, 1964), but complex afférents including the suprachiasmatic nucleus, limbic structures and 5-hydroxytryptamine-(5-HT) containing ascending neuronal projections of the nucleus dorsalis raphe (NDR) also participate in the control of ovulation (Velasco & Taleisnik, 1969; Barofsky, 1975).…”

Section: Introductionmentioning

confidence: 99%

Effects of Progesterone and Its Interaction With Oestradiol in Hypothalamic and Raphe Nuclei on Luteinizing Hormone in Plasma

Wandscheer¹,

Alessio²,

Ladosky³

1980

Journal of Endocrinology

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Microinjection of progesterone into the preoptic area (POA) of the rat on either day 2 of dioestrus or the morning of pro-oestrus inhibited the ovulatory peak of LH which would normally appear during the afternoon of pro-oestrus. However, when progesterone plus oestrogen were used, the inhibition of the surge of LH was observed only if the microinjection was applied on the morning of day 2 of dioestrus. Microinjection of progesterone into the medial basal hypothalamus (MBH) at day 2 of dioestrus advanced the ovulatory peak by 24 h. This effect was also observed when progesterone and oestrogen were simultaneously infused. Progesterone injected into the MBH on the morning of pro-oestrus significantly increased the release of LH during the afternoon. This effect was also observed when progesterone plus oestrogen were simultaneously infused. Application of progesterone alone or with oestrogen to the nucleus dorsalis raphe on the morning of either day 2 of dioestrus or pro-oestrus induced a significant decrease of the levels of LH in plasma and prevented the appearance of the ovulatory peak during the afternoon of pro-oestrus. These findings indicated that these two steroids have differential actions when infused into various hypothalamic and extrahypothalamic nuclei. Consequently, it is concluded that in studies on the effects of ovarian hormones it is important to take into account not only the isolated action of each one of them, but also their interaction on the effects of the diverse neural structures involved in the control of ovulation on each day of the ovulatory cycle.

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Progesterone-Induced Luteinizing Hormone Release in Oestrogen-Primed Ovariectomized Rats After Destruction of Mid-Brain Inputs to Suprachiasmatic Nuclei

Cited by 11 publications

References 5 publications

Neural Regulation of Luteinizing Hormone Secretion in the Rat*

Neural Regulation of Luteinizing Hormone Secretion in the Rat*

Median Raphe Stimulation and Sham Procedures Inhibit the LH Surge

Effects of Progesterone and Its Interaction With Oestradiol in Hypothalamic and Raphe Nuclei on Luteinizing Hormone in Plasma

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