ZUR BEDEUTUNG DES HYPOPHYSÄREN LUTEINISIERUNGSHORMONS FÜR SCHWANGERSCHAFT, GEBURT UND LACTATION BEI DER RATTE

1970 ◽  
Vol 65 (3_Suppl) ◽  
pp. S5-S32 ◽  
Author(s):  
K. Loewit
Keyword(s):  
Luteinizing Hormone ◽  
Early Pregnancy ◽  
Hydroxysteroid Dehydrogenase ◽  
The State ◽  
Termination Of Pregnancy ◽  
Progesterone Level ◽  
Corpora Lutea ◽  
Regulatory Properties ◽  
Duration Of Pregnancy

ABSTRACT The role of luteinizing hormone (LH) for the maintenance of pregnancy, parturition and lactation was investigated by immunological and histochemical methods in the rat. Neutralisation of endogenous rat-LH with Rabbit-Anti-Bovine-LH-Serum (selective hypophysectomy) from days 7-12 of pregnancy resulted in reabsorption of the foetuses and the reappearance of strong 20α-hydroxysteroid-dehydrogenase (20α-OHSD) activity in the corpora lutea (CL) of pregnancy, which normally show no such activity at that time. This effect could be prevented in part by concurrent pregnenolone administration and fully by progesterone, but was not influenced by oestrogen or prolactin. It is concluded that in early pregnancy LH is the main luteotrophic hormone in the rat even though prolactin might act synergistically with it. Antiserum treatment after the 12th day of gestation had no influence on the state or duration of pregnancy or on parturition. LH-injections during the first half of pregnancy had no luteolytic effects i. e. they did not activate 20α-OHSD activity. After day 16 they advanced the reappearance of the enzyme, but delayed parturition or resulted in stillbirths. Neither LH nor antiserum seemed to alter lactation. Since progesterone prevented both the termination of pregnancy and the recurrence of 20α-OHSD activity, it should have some regulatory properties on the enzyme. It is discussed whether the gonadotrophin-dependent progesterone level could regulate the 20α-OHSD activity rather than result from it.

THE PERSISTENCE OF PROGESTERONE SECRETION IN PREGNANT RATS AFTER HYPOPHYSECTOMY AND HYSTERECTOMY: A COMPARISON WITH PSEUDOPREGNANT, DECIDUOMATABEARING PSEUDOPREGNANT, AND LACTATING RATS

1973 ◽  
Vol 57 (1) ◽  
pp. 63-74 ◽  
Author(s):  
I. ROTHCHILD ◽  
R. B. BILLIAR ◽  
I. T. KLINE ◽  
G. PEPE
Keyword(s):  
Luteinizing Hormone ◽  
Clearance Rate ◽  
Progesterone Level ◽  
Corpora Lutea ◽  
Metabolic Clearance ◽  
Metabolic Clearance Rate ◽  
Serum Progesterone ◽  
Pregnant Rats ◽  
Oestrogen Treatment ◽  
Progesterone Secretion

SUMMARY To test the hypothesis of Raj & Moudgal (1970) that luteinizing hormone (LH) is the essential luteotrophin during pregnancy in the rat, pregnant rats were hypophysectomized and hysterectomized on either day 12 or day 15 of pregnancy, and the changes in peripheral serum progesterone level measured. The serum progesterone level remained at approximately the day-12 value for 3 days after hypophysectomy and hysterectomy on day 12, but fell drastically and remained low after the same operation on day 15, or in pseudopregnant rats operated on on day 12, or after removal of the ovaries from pregnant rats on day 12. Oestrogen treatment increased the serum progesterone level slightly in the pregnant rats after hypophysectomy and hysterectomy, but not after ovariectomy; it had no effect in the pseudopregnant rats, with or without deciduomata, or in lactating rats nursing litters of seven to nine pups. The corpora lutea stopped growing or slowly regressed soon after hypophysectomy—hysterectomy in all except the pregnant rats operated on on day 12 and treated with oestrogen, and in these growth was very slight. The luteal content of progesterone did not change for 3 days after hypophysectomy—hysterectomy on day 12 of pregnancy, and fell slightly thereafter. The metabolic clearance rate of progesterone was not significantly changed by hypophysectomy—hysterectomy. It thus appears that true secretion of progesterone continues in pregnant rats for about 3 days after day 12 in the absence of the pituitary and placentas, but at a much lower rate than that found in intact, or in day-12 hypophysectomized pregnant rats (Pepe & Rothchild, 1972a). The placental luteotrophin thus seems to increase the rate of progesterone secretion in the absence of LH. The results do not seem to fit with the hypothesis that LH is essential for progesterone secretion.

scholarly journals Lysophosphatic acid modulates prostaglandin secretion in the bovine uterus

Reproduction ◽  
2009 ◽  
Vol 137 (1) ◽  
pp. 95-105 ◽  
Author(s):  
Izabela Woclawek-Potocka ◽  
Junichi Komiyama ◽  
Jean Sebastian Saulnier-Blache ◽  
Edyta Brzezicka ◽  
Mamadou Moussa Bah ◽  
...  
Keyword(s):  
Gene Expression ◽  
Estrous Cycle ◽  
Dehydrogenase Activity ◽  
Lysophosphatidic Acid ◽  
Early Pregnancy ◽  
Reproductive Tract ◽  
Hydroxysteroid Dehydrogenase ◽  
Lpa Receptor

Lysophosphatidic acid (LPA) modulates prostaglandin (PG) synthesis via LPA receptor 3 (LPAR3) in the murine endometrium. The lack of functional LPAR3 in mice may lead to embryo mortality. In the present study, we examined the role of LPA in the bovine uterus. We confirmed that LPA is locally produced and released from the bovine endometrium. Moreover, there are enzymes involved in LPA synthesis (phospholipase(PL)D2and PLA2G1B) in the bovine endometrium during estrous cycle and early pregnancy. Expression of the receptor for LPA (LPAR1) was positively correlated with the expression ofPGE2synthase(PGES) and negatively correlated with the expression ofPGF2αsynthase(aldose reductase with 20 α-hydroxysteroid dehydrogenase activity –PGFS) during early pregnancy.In vivoLPA induced P4 and PGE2secretion was inhibited by LPAR1 antagonist (Ki16425). The overall results indicate that LPA is locally produced and released from the bovine endometrium. Moreover,LPAR1gene expression in the endometrium during the estrous cycle and early pregnancy indicates that LPA may play autocrine and/or paracrine roles in the bovine uterus.LPAR1gene expression is positively correlated with the expression of the enzyme responsible for luteotropic PGE2production (PGES) in endometrium. In cow, LPA stimulates P4 and PGE2secretion. Thus, LPA in the bovine reproductive tract may indirectly (via endometrium) or directly support corpus luteum action via the increase of P4 synthesis and the increase of PGE2/PGF2αratio. It suggests that LPA may serve as an important factor in the maintenance of early pregnancy in cow.

THE ROLE OF PROLACTIN IN THE REGULATION OF TESTICULAR FUNCTION: THE EFFECT OF PROLACTIN AND LUTEINIZING HORMONE ON 3β-HYDROXYSTEROID DEHYDROGENASE ACTIVITY IN THE TESTES OF MICE AND RATS

1971 ◽  
Vol 50 (4) ◽  
pp. 619-623 ◽  
Author(s):  
A. A. HAFIEZ ◽  
J. E: PHILPOTT ◽  
A. BARTKE
Keyword(s):  
Luteinizing Hormone ◽  
Dehydrogenase Activity ◽  
Normal Mouse ◽  
Hydroxysteroid Dehydrogenase ◽  
Testicular Function ◽  
Hypophysectomized Rats ◽  
Dwarf Mice

SUMMARY Administration of 100 μg prolactin twice daily for 3 days increased 3β-hydroxysteroid dehydrogenase (3β-HSD) activity in the testes of dwarf mice compared with that found in the normal mouse. In hypophysectomized rats, prolactin (200 μg, same regimen) was without effect when given alone, whereas 5 μg luteinizing hormone (LH) alone injected twice daily, increased 3β-HSD activity to above normal. When prolactin and LH were administered in combination, 3β-HSD activity was raised to normal levels only.

scholarly journals A protective role of resveratrol against the effects of immobilization stress in corpora lutea of mice in early pregnancy

2020 ◽  
Vol 19 (7) ◽  
pp. 1857-1866
Author(s):  
Saif ULLAH ◽  
Sheeraz MUSTAFA ◽  
Wael ENNAB ◽  
Muhammad JAN ◽  
Muhammad SHAFIQ ◽  
...  
Keyword(s):  
Early Pregnancy ◽  
Immobilization Stress ◽  
Protective Role ◽  
Corpora Lutea

Role of plasma progesterone concentration in early pregnancy of the ewe

1981 ◽  
Vol 21 (113) ◽  
pp. 562 ◽  
Author(s):  
FD Brien ◽  
IA Cumming ◽  
IJ Clarke ◽  
CS Cocks
Keyword(s):  
Early Pregnancy ◽  
Progesterone Level ◽  
Progesterone Concentration ◽  
Plasma Progesterone ◽  
Peripheral Plasma

Eighty-eight maiden and 125 mature Merino ewes were grazed on green irrigated pasture or given dry hay on a fallow area with or without a lupin grain supplement just before and during mating. Progesterone concentrations in peripheral plasma were measured at 12 d after coitus. Progesterone concentration was lower (2.27 vs 2.87 ng/ml, P < 0.001 ) when lupins were fed, and maiden ewes had higher progesterone concentrations than mature ewes (2.75 vs 2.36 ng/ml, P < 0.05). Pregnant ewes had higher progesterone concentrations than non-pregnant ewes (2.77 vs 2.36 ng/ml, P < 0.05), and ewes with two ovulations had higher progesterone concentrations than ewes with a single ovulation (3.13 vs 2.08 ng/ml, P < 0.001). There was an interaction between pasture type and lupin supplement, with lupins depressing progesterone level more on green irrigated pasture (lupins 2.11 ng/ml, no lupins 3.00 ng/ml, P < 0.05) than on dry pasture (lupins 2.45 ng/ml, no lupins 2.74 ng/ml, P < 0.05). The results confirm that a high plane of nutrition at mating lowers progesterone levels in plasma and suggest that this may be a factor in the increase in embryo deaths when ewes are fed lupin grain supplements.

PROGESTERONE AND 20α-HYDROXYSTEROID-DEHYDROGENASE REGULATION IN THE CORPUS LUTEUM OF THE PREGNANT RAT

1979 ◽  
Vol 90 (1) ◽  
pp. 176-184 ◽  
Author(s):  
K. Loewit ◽  
N. Zambelis
Keyword(s):  
Wistar Rats ◽  
Time Course ◽  
Hydroxysteroid Dehydrogenase ◽  
Mechanisms Of Action ◽  
Corpora Lutea ◽  
Pregnant Rat ◽  
Female Wistar Rats ◽  
Series Of Experiments ◽  
Complex Regulation

ABSTRACT Female Wistar rats were mated and passively immunized against bovine luteinizing hormone (bLH) between days 7–12 of gestation. In a first series of experiments the effect of simultaneous progesterone treatment on the histochemically detectable activity of 20α-hydroxysteroiddehydrogenase (20α-OHSD) in the corpora lutea of pregnancy was evaluated. In other experiments the exact time course was established between the first histologically demonstrable signs of termination of pregnancy and the appearance of 20α-OHSD activity in corpora lutea of pregnancy. It was found that progesterone substitution not only prevented the deleterious effects of the anti-bLH-serum on gestation but also the re-appearance of 20α-OHSD activity in the corpora lutea of pregnancy up to day 12 of pregnancy. Moreover in animals injected with anti-bLH-serum from day 7 on and sacrificed on days 8–2, signs of foetal destruction clearly preceded the pathological re-appearance of 20α-OHSD activity by 2–3 days. These results support previous findings on a direct or indirect role of progesterone in the complex regulation of 20α-OHSD activity. Possible mechanisms of action are discussed.

scholarly journals A single dose of allopregnanolone affects rat ovarian morphology and steroidogenesis

Reproduction ◽  
2017 ◽  
Vol 153 (1) ◽  
pp. 75-83 ◽  
Author(s):  
Laura Tatiana Pelegrina ◽  
Antonella Rosario Ramona Cáceres ◽  
Fernando Alfredo Giuliani ◽  
Joana Antonella Asensio ◽  
Fernanda Parborell ◽  
...  
Keyword(s):  
Reproductive Function ◽  
Serum Levels ◽  
Hydroxysteroid Dehydrogenase ◽  
Spectrophotometric Analysis ◽  
Enzymatic Activities ◽  
Corpora Lutea ◽  
Medial Basal Hypothalamus ◽  
Ovarian Morphology ◽  
Progesterone Metabolite

Allopregnanolone, a progesterone metabolite, is one of the best characterized neurosteroids. In a dose that mimics serum levels during stress, allopregnanolone inhibits sexual receptivity and ovulation and induces a decrease in luteinizing hormone levels. The aim of this work was to examine the effect of an intracerebroventricular administration of allopregnanolone on ovarian morphophysiology; serum and tissue levels of progesterone and estrogen; and enzymatic activity of 3β-hydroxysteroid dehydrogenase, 20α-hydroxysteroid dehydrogenase and 3α-hydroxysteroid oxido-reductase in the ovary and in the medial basal hypothalamus on the morning of estrus. Ovarian morphology was analyzed under light microscopy. The hormone assays were performed by radioimmunoassay. The enzymatic activities were measured by spectrophotometric analysis. The morphometric analysis revealed that, in allopregnanolone-treated animals, the number of secondary and Graafian follicles was decreased, whereas that of atretic follicles and cysts was significantly increased. Some cysts showed luteinized unruptured follicles. There were no differences in the number of tertiary follicles or corpora lutea in comparison with the corresponding control groups. In allopregnanolone-treated animals, progesterone serum levels were increased, whereas ovarian progesterone levels were decreased. Moreover, 3β-HSD and 3α-HSOR enzymatic activities were increased in the medial basal hypothalamus, whereas ovarian levels were decreased. The enzyme 20α-hydroxysteroid dehydrogenase showed the opposite profile. The results of this study showed that allopregnanolone interferes on ovarian steroidogenesis and ovarian morphophysiology in rats, providing a clear evidence for the role of this neurosteroid in the control of reproductive function under stress situations.Free Spanish abstract: A Spanish translation of this abstract is freely available athttp://www.reproduction-online.org/content/153/1/75/suppl/DC1.

EFFECT OF LUTEINIZING HORMONE AND HUMAN CHORIONIC GONADOTROPHIN ON CORPORA LUTEA IN RATS BEARING PITUITARY AUTOGRAFTS

1969 ◽  
Vol 43 (1) ◽  
pp. 61-66
Author(s):  
S. J. STOLZENBERG ◽  
R. G. EGGERT ◽  
F. E. HARRINGTON ◽  
W. H. LINKENHEIMER
Keyword(s):  
Luteinizing Hormone ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Corpora Lutea ◽  
Uterine Weight ◽  
Luteal Regression ◽  
Final Injection ◽  
Hypophysectomized Rats ◽  
Metabolic Activities

SUMMARY Rats bearing pituitary autotransplants received injections of luteinizing hormone (LH) for 9 days or human chorionic gonadotrophin (HCG) for 6 days. Both compounds caused significant increases in ovarian and uterine weights as well as vaginal mucification, observed 1 day after the last injection. Luteal regression and a decrease in uterine weight compared to control animals were observed 35 days after final injection with each compound. Continuous dioestrous vaginal smears were observed in all groups. In hypophysectomized rats, HCG, but not LH, caused an increase in ovarian weight which was statistically significant on the day after the final injection in one of two experiments. Uterine weights were increased after LH and HCG treatments. Vaginal cornification was evident 3–4 days after initiation of treatment with either hormone. When ovariectomy preceded hypophysectomy, there was no increase in uterine weight and no vaginal cornification in response to HCG treatment indicating the essential role of the ovaries. The effects in rats bearing auto-transplanted pituitaries as well as in hypophysectomized rats are attributed to the stimulation of oestrogen secretion from the ovaries. It is suggested that the rapid rate of luteal regression in rats bearing transplanted pituitaries is initiated by an increase in metabolic activities due to LH or HCG.

Role of Luteinizing Hormone in Control of Oviduct Function

2000 ◽  
Vol 35 (3-4) ◽  
pp. 129-133
Author(s):  
B Gawronska ◽  
A Stepien ◽  
AJ Ziecik
Keyword(s):  
Luteinizing Hormone
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