Absence of Increased Neuropeptide Y Neuronal Activity before and during the Luteinizing Hormone (LH) Surge May Underlie the Attenuated Preovulatory LH Surge in Middle-Aged Rats
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چکیده
منابع مشابه
Intracerebroventricular Infusion of Vasoactive Intestinal Peptide Rescues the Luteinizing Hormone Surge in Middle-Aged Female Rats
Reproductive aging is characterized by delayed and attenuated luteinizing hormone (LH) surges apparent in middle-aged rats. The suprachiasmatic nucleus (SCN) contains the circadian clock that is responsible for the timing of diverse neuroendocrine rhythms. Electrophysiological studies suggest vasoactive intestinal peptide (VIP) originating from the SCN excites gonadotropin-releasing hormone (Gn...
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Reproduction is adversely affected by alcohol abuse in humans and laboratory animals. In rats, alcohol exposure suppresses both luteinizing hormone (LH) and sex steroid secretion, although consensus is lacking as to which level of the hypothalamic-pituitary-gonadal (HPG) axis is primarily affected. We tested the hypothesis that acute alcohol treatment inhibits the HPG axis by blunting release o...
متن کاملEvaluation of LH secretory dynamics during the rat proestrous LH surge.
The preovulatory luteinizing hormone (LH) surge results from the integration of complex interactions among gonadal steroids and hypothalamic and pituitary hormones. To evaluate changes in LH secretory dynamics that occur during the rat LH surge, we have 1) obtained frequently sampled serum LH concentration time series, 2) used both waveform-dependent and waveform-independent convolution analyse...
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This study aimed to investigate whether the preovulatory LH surge mechanism is involved in sheep-to-sheep interaction for oestrous synchronisation. For that purpose, anoestrous ewes were inserted with intravaginal progestagen sponges for 13 days to induce ovulation. Upon sponge withdrawal, they were introduced either to 4 rams (n = 6, ram group), or to 4 ewes which were in follicular period (n ...
متن کاملNeuropeptide Y in the medial basal hypothalamus and medial preoptic area during the induction of LH surge may be controlled by locus coeruleus.
The multiple control of gonadotropin releasing hormone (GnRH)/luteinizing hormone (LH) secretion involves locus coeruleus (LC) and neuropeptide Y (NPY). The objective of the present study was to analyze the possible contribution of the LC to the control of NPY activity in the medial basal hypothalamus (MBH) and medial preoptic area (MPOA) during the LH surge induced by estrogen (E(2)) and proge...
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ژورنال
عنوان ژورنال: Endocrinology
سال: 1998
ISSN: 0013-7227
DOI: 10.1210/en.139.2.696