Changes in plasma kininogen levels in rats before ovulation, and after treatment with luteinizing hormone and oestradiol-17β

1983 ◽  
Vol 104 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Caroline Smith ◽  
A. M. Perks
Keyword(s):  
Body Weight ◽  
Luteinizing Hormone ◽  
Lh Surge ◽  
Plasma Oestradiol

Abstract. The pre-ovulatory fall in plasma kininogens in rats with 4 day oestrous cycles started between 12.00 and 15.00 h pro-oestrus, reached a maximum decline of 51% by 18.00 h pro-oestrus, and started to recover before ovulation. Because these changes appeared to correspond with the LH-surge, and to follow the peak in plasma oestradiol-17β levels, both of these hormones were tested for possible effects on plasma kininogens. Intracardiac injections of 110 IU of equine LH into dioestrous rats were followed by a decline of 30.8 ± 6.7% in plasma kininogens, 6 h after injection (significant, P< 0.01). Values were still depressed, but recovering, 12 h after treatment; the reduction was 21.3 ± 5.8% (significant, P < 0.01). Controls showed no decline. Injections of oestradiol-17β (1.0 μg/100 g body weight) produced no significant effects. It is suggested that the LH surge may be responsible, at least in part, for the decline in plasma kininogens seen before ovulation.

PLASMA OESTRADIOL AND HUMAN LUTEINIZING HORMONE DURING THE MENSTRUAL CYCLE

1969 ◽  
Vol 61 (1_Suppl) ◽  
pp. S213 ◽  
Author(s):  
C. S. Corker ◽  
F. Naftolin ◽  
D. Exley
Keyword(s):  
Menstrual Cycle ◽  
Luteinizing Hormone ◽  
Plasma Oestradiol

Effects of alarin on food intake, body weight and luteinizing hormone secretion in male mice

Neuropeptides ◽  
2012 ◽  
Vol 46 (2) ◽  
pp. 99-104 ◽  
Author(s):  
Gregory S. Fraley ◽  
Emily Leathley ◽  
Nicole Lundy ◽  
Emily Chheng ◽  
Issurah King ◽  
...  
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Luteinizing Hormone ◽  
Hormone Secretion ◽  
Male Mice ◽  
Luteinizing Hormone Secretion

EVIDENCE FOR A DOPAMINERGIC COMPONENT IN THE SERIES OF NEURAL EVENTS THAT LEAD TO THE PRO-OESTROUS SURGE OF LH

1977 ◽  
Vol 85 (1) ◽  
pp. 18-24 ◽  
Author(s):  
James A. Clemens ◽  
Frank C. Tinsley ◽  
Ray W. Fuller
Keyword(s):  
Luteinizing Hormone ◽  
Inhibitory Effects ◽  
Brain Dopamine ◽  
Lh Surge ◽  
Lh Release

ABSTRACT The possible participation of dopamine in the neural events that lead to the pro-oestrous surge of luteinizing hormone (LH) was investigated utilizing a dopaminergic ergoline derivative (lergotrile mesylate). Administration of reserpine (2.0 mg/kg, ip) to rats on the day of pro-oestrus depicted brain dopamine and norepinephrine and prevented the LH surge and ovulation. Administration of lergotrile mesylate prior to or at the same time as reserpine prevented the inhibitory effects of reserpine on LH release and on ovulation in about half of the animals. When lergotrile mesylate was given on the morning of pro-oestrus, the LH surge was advanced. The results indicate that there is a dopaminergic component in the series of neural events that precede the surge of LH on prooestrus, and that the dopaminergic stimulus precedes the LH surge by about 4–5 h.

scholarly journals Effect of androgen on Kiss1 expression and luteinizing hormone release in female rats

2017 ◽  
Vol 233 (3) ◽  
pp. 281-292 ◽  
Author(s):  
Kinuyo Iwata ◽  
Yuyu Kunimura ◽  
Keisuke Matsumoto ◽  
Hitoshi Ozawa
Keyword(s):  
Luteinizing Hormone ◽  
Arcuate Nucleus ◽  
Female Rats ◽  
Hormone Release ◽  
Lh Surge ◽  
Continuous Release ◽  
Ovulatory Dysfunction ◽  
Lh Release ◽  
Gonadotrophin Releasing Hormone ◽  
Lh Secretion

Hyperandrogenic women have various grades of ovulatory dysfunction, which lead to infertility. The purpose of this study was to determine whether chronic exposure to androgen affects the expression of kisspeptin (ovulation and follicle development regulator) or release of luteinizing hormone (LH) in female rats. Weaned females were subcutaneously implanted with 90-day continuous-release pellets of 5α-dihydrotestosterone (DHT) and studied after 10 weeks of age. Number of Kiss1-expressing cells in both the anteroventral periventricular nucleus (AVPV) and arcuate nucleus (ARC) was significantly decreased in ovary-intact DHT rats. Further, an estradiol-induced LH surge was not detected in DHT rats, even though significant differences were not observed between DHT and non-DHT rats with regard to number of AVPV Kiss1-expressing cells or gonadotrophin-releasing hormone (GnRH)-immunoreactive (ir) cells in the presence of high estradiol. Kiss1-expressing and neurokinin B-ir cells were significantly decreased in the ARC of ovariectomized (OVX) DHT rats compared with OVX non-DHT rats; pulsatile LH secretion was also suppressed in these animals. Central injection of kisspeptin-10 or intravenous injection of a GnRH agonist did not affect the LH release in DHT rats. Notably, ARC Kiss1-expressing cells expressed androgen receptors (ARs) in female rats, whereas only a few Kiss1-expressing cells expressed ARs in the AVPV. Collectively, our results suggest excessive androgen suppresses LH surge and pulsatile LH secretion by inhibiting kisspeptin expression in the ARC and disruption at the pituitary level, whereas AVPV kisspeptin neurons appear to be directly unaffected by androgen. Hence, hyperandrogenemia may adversely affect ARC kisspeptin neurons, resulting in anovulation and menstrual irregularities.

Progesterone receptors in AVPV kisspeptin neurons are sufficient for positive feedback induction of the LH surge

Endocrinology ◽  
2021 ◽  
Author(s):  
Margaret A Mohr ◽  
Lourdes A Esparza ◽  
Paige Steffen ◽  
Paul E Micevych ◽  
Alexander S Kauffman
Keyword(s):  
Luteinizing Hormone ◽  
Transgenic Mice ◽  
Positive Feedback ◽  
Progesterone Receptors ◽  
Critical Importance ◽  
Estrogen And Progesterone Receptors ◽  
Lh Surge ◽  
Normal Fertility ◽  
Gnrh Neurons ◽  
The Brain

Abstract Kisspeptin, encoded by Kiss1, stimulates GnRH neurons to govern reproduction. In female rodents, estrogen-sensitive kisspeptin neurons in the rostral anteroventral periventricular (AVPV) hypothalamus are thought to mediate estradiol (E2)-induced positive feedback induction of the preovulatory luteinizing hormone (LH) surge. AVPV kisspeptin neurons co-express estrogen and progesterone receptors (PGR) and are activated during the LH surge. While E2 effects on kisspeptin neurons have been well-studied, progesterone’s regulation of kisspeptin neurons is less understood. Using transgenic mice lacking PGR exclusively in kisspeptin cells (termed KissPRKOs), we previously demonstrated that progesterone action specifically in kisspeptin cells is essential for ovulation and normal fertility. Unlike control females, KissPRKO females did not generate proper LH surges, indicating that PGR signaling in kisspeptin cells is required for proper positive feedback. However, since PGR was knocked out from all kisspeptin neurons in the brain, that study was unable to determine the specific kisspeptin population mediating PGR action on the LH surge. Here, we used targeted Cre-mediated AAV technology to re-introduce PGR selectively into AVPV kisspeptin neurons of adult KissPRKO females, and tested whether this rescues occurrence of the LH surge. We found that targeted upregulation of PGR in kisspeptin neurons exclusively in the AVPV is sufficient to restore proper E2-induced LH surges in KissPRKO females, suggesting that this specific kisspeptin population is a key target of the necessary progesterone action for the surge. These findings further highlight the critical importance of progesterone signaling, along with E2 signaling, in the positive feedback induction of LH surges and ovulation.

PLASMA AND PITUITARY LUTEINIZING HORMONE CONCENTRATIONS AND PERIPHERAL PLASMA OESTRADIOL CONCENTRATION DURING EARLY PREGNANCY AND AFTER THE ADMINISTRATION OF PROGESTATIONAL STEROIDS IN THE RAT

1972 ◽  
Vol 53 (1) ◽  
pp. 31-35 ◽  
Author(s):  
K. BROWN-GRANT ◽  
C. S. CORKER ◽  
F. NAFTOLIN
Keyword(s):  
Luteinizing Hormone ◽  
Marked Decrease ◽  
Single Injection ◽  
Normal Pregnancy ◽  
Oestrous Cycle ◽  
Pregnant Rats ◽  
Pregnant Rat ◽  
Peripheral Plasma ◽  
Blastocyst Implantation ◽  
Plasma Oestradiol

SUMMARY Plasma luteinizing hormone (LH) concentrations were already lower on Day 2 of pregnancy than at the same time after the preceding ovulation in the non-pregnant rat, and fell progressively up to Day 16 of pregnancy. No evidence was obtained of any increase at the time when the ovulatory surge of LH would have occurred if the animal had not become pregnant. Pituitary LH concentration was lower in mated rats on the morning of Day 0 of pregnancy than in unmated controls on the morning of the day of oestrus. Subsequently it increased slowly to reach a level higher than at any stage of the oestrous cycle by Day 8 of pregnancy and remained high until at least Day 16 of pregnancy. Peripheral plasma oestradiol concentration increased late on Day 2 of pregnancy and was still raised on Day 4 but was never more than about one fourth of the peak concentration seen on the morning of prooestrus during the oestrous cycle. There were similar changes in plasma LH and oestradiol concentrations in the 48 h after a single injection of 2·5mg progesterone on the morning of the day of dioestrus, a procedure that delays ovulation by 1 or 2 days. Administration of a synthetic progestational compound (medroxyprogesterone acetate) to pregnant rats delayed blastocyst implantation and the delay was associated with a marked decrease in peripheral plasma LH to levels below those of normal pregnancy.

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