OESTROGEN SYNTHESIS IN RAT OVARIES IN VITRO: EFFECTS OF ENDOGENOUS AND EXOGENOUS GONADOTROPHINS

1972 ◽  
Vol 53 (3) ◽  
pp. 397-406 ◽  
Author(s):  
BRENDA ROBINSON ◽  
R. E. OAKEY
Keyword(s):  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Oestrous Cycle ◽  
The Other ◽  
Ovarian Vein ◽  
Hormone Activity ◽  
In Vitro Effects ◽  
Stimulating Hormone

SUMMARY The rate of synthesis of [14C]oestrone and [14C]oestradiol-17β from [14C]testosterone in vitro by ovaries from rats at different stages of the oestrous cycle was measured. The rate of [14C]oestrogen synthesis was highest in ovaries taken from rats in pro-oestrus and lowest in ovaries taken from rats early in the dioestrous phase of the cycle. Rates of synthesis in ovaries obtained from rats in the late dioestrous stage were intermediate between the rates of the other groups. The rates of [14C]oestrogen synthesis at these periods of the cycle paralleled the concentrations of oestrogens in ovarian vein plasma reported by other authors. Gonadotrophin preparations with either luteinizing hormone activity or both follicle-stimulating hormone and luteinizing hormone activities had no effect on [14C]oestrogen synthesis by rat ovaries in vitro at any of these stages of the oestrous cycle.

THE EFFECTS OF SYNTHETIC GONADOTROPHIN RELEASING FACTOR ON THE RELEASE OF LUTEINIZING HORMONE AND FOLLICLE-STIMULATING HORMONE FROM OVINE PITUITARY TISSUE IN VITRO

1973 ◽  
Vol 58 (3) ◽  
pp. 387-391 ◽  
Author(s):  
D. B. CRIGHTON
Keyword(s):  
Luteinizing Hormone ◽  
Incubation Medium ◽  
Synthetic Peptides ◽  
Follicle Stimulating Hormone ◽  
The Other ◽  
Pituitary Tissue ◽  
Incubation System ◽  
Stimulating Hormone

SUMMARY A synthetic decapeptide gonadotrophin releasing factor was tested for effects on the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) using an ovine pituitary incubation system. The effects of other synthetic peptides used at similar doses were studied. The synthetic decapeptide consistently provoked significant increases in the LH content of the incubation medium at doses equal to or in excess of 0·5 ng/flask (0·2 ng/ml medium). Significant increases in the FSH content of the incubation medium at doses equal to or in excess of 0·25 ng/flask (0·1 ng/ml medium) were observed. The other synthetic peptides failed to influence LH or FSH release in vitro even at a dose 20–40 times greater. The results demonstrate that the decapeptide releases both LH and FSH from sheep pituitary tissue, suggesting that it may play a role in the release of both hormones in vivo in the sheep.

scholarly journals Identification of amino-acids in the alpha-subunit first and third loops that are crucial for the heterospecific follicle-stimulating hormone activity of equid luteinizing hormone/choriogonadotropin

2004 ◽  
pp. 877-884 ◽  
Author(s):  
M Chopineau ◽  
N Martinat ◽  
JF Gibrat ◽  
C Galet ◽  
F Lecompte ◽  
...  
Keyword(s):  
Amino Acids ◽  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Alpha Subunit ◽  
Hormone Activity ◽  
Alpha Subunits ◽  
In Vitro Bioassays ◽  
Fsh Bioactivity ◽  
Stimulating Hormone

OBJECTIVE: To identify amino-acids in the alpha-subunit important for expression of heterospecific FSH activity of horse (e) LH/choriogonadotropin (CG) (eLH) and donkey (dk) LH/CG (dkLH) (FSH/LH ratio ten times higher for eLH than for dkLH); this FSH activity absolutely requires an equid (donkey or horse) alpha-subunit combined with an equid beta-LH subunit. DESIGN: Chimeric alpha-subunits possessing the first 63 amino-acids of the porcine (p) and the last 33 amino-acids of the donkey alpha-subunit (alphap-dk) and the inverse (alphadk-p) were constructed. Porcine-specific amino-acids were introduced by mutagenesis in donkey alpha-subunit at positions 70, 85, 89, 93 and 96 (alphadk5xmut), 18 (alphadkK18E) or 78 (alphadkI78A). METHODS: These different alpha-subunits were co-transfected in COS-7 cells with beta-eLH, beta-dkLH and beta-eFSH. The LH and FSH bioactivities of the dimers were then assessed in two heterologous in vitro bioassays. RESULTS: alphap-dk or alphadk-p exhibited FSH activity when co-expressed with beta-eLH but not with beta-dkLH. alphadkK18E or alphadkI78A gave hybrids with no FSH activity and important LH activity when expressed with beta-dkLH. alphadkI78A/betaeLH displayed an FSH/LH ratio as low as that of dkLH. However, mutation at 78 in alpha-dk had no effect on FSH bioactivity when co-expressed with beta-eFSH. CONCLUSIONS: Amino-acids present in both the first two-thirds and the last third of the alpha-subunit of equid LHs are involved in their heterologous biospecificity. Ile alpha78 exerts as strong an influence on it as the beta102-103 residues. By contrast, this residue plays no role in the FSH specificity of eFSH.

scholarly journals The ratio of exogenous Luteinizing hormone to Follicle stimulating hormone administered for controlled ovarian stimulation is associated with oocytes’ number and competence

2020 ◽  
Vol 40 (1) ◽  
Author(s):  
Dragos Albu ◽  
Alice Albu
Keyword(s):  
Luteinizing Hormone ◽  
Ovarian Stimulation ◽  
Follicle Stimulating Hormone ◽  
Fertilization Rate ◽  
Controlled Ovarian Stimulation ◽  
Human Menopausal Gonadotropin ◽  
Male Factor ◽  
Entire Study ◽  
Stimulating Hormone

Abstract We performed a retrospective study aiming to study the relationship between the ratio of the exogenous luteinizing hormone to follicle stimulating hormone (LH/FSH) administrated for controlled ovarian stimulation (COS) and the number and competence of the oocytes retrieved for in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). Eight hundred sixty-eight consecutive infertile patients (mean age 34.54 ± 4.01 years, mean anti-Müllerian hormone (AMH) 2.94 ± 2.07 ng/ml) treated with long agonist protocol and a mixed gonadotropin protocol (human menopausal gonadotropin in association with recombinant FSH (recFSH)) who performed IVF/ICSI between January 2013 and February 2016, were included. Patients with severe male factor were excluded. LH/FSH was calculated based on total doses of the two gonadotropins. We found, after adjustment for confounders, a positive relationship between LH/FSH and the retrieved oocytes’ (β = 0.229, P<0.0001) and zygotes’ number (β = 0.144, P<0.0001) in the entire study group and in subgroups according to age (<35 and ≥35 years) and ovarian reserve (AMH < 1.1 and ≥ 1.1 ng/ml). The fertilization rate was positively associated with LH/FSH in patients with LH/FSH in the lowest three quartiles (below 0.77) (β = 0.096, P=0.034). However, patients in the fourth quartile of LH/FSH had a lower fertilization rate as compared with patients in quartiles 1–3 which, after adjustment for covariates, was only marginally negatively related with LH/FSH (β = −0.108, P=0.05). In conclusion, our results suggest that the adequate LH/FSH administrated during COS can improve the oocytes’ and zygotes’ number in IVF/ICSI cycles, but also the fertilization rate when a certain proportion of LH/FSH is not exceeded.

Endocrine and local testicular regulation

2011 ◽  
pp. 1347-1353
Author(s):  
Ilpo Huhtaniemi
Keyword(s):  
Growth Factors ◽  
Luteinizing Hormone ◽  
Leydig Cell ◽  
Follicle Stimulating Hormone ◽  
Regulatory System ◽  
The Other ◽  
Seminiferous Tubules ◽  
Testicular Function ◽  
Cell Product ◽  
Stimulating Hormone

The testis has two functions, androgen production and spermatogenesis, and a key role in their regulation is played by the two pituitary gonadotropins, luteinizing hormone and follicle-stimulating hormone (FSH). Other hormones and growth factors also influence testicular function, often by modulating the gonadotropin effects. Moreover, a plethora of local paracrine and autocrine signals within the testis are known. The main testicular hormone, testosterone, a Leydig cell product, regulates spermatogenesis in seminiferous tubules in paracrine fashion. The other functions of testosterone are endocrine, occurring outside the testis. This chapter summarizes the main hormonal regulatory system of the testis, the hypothalamic–pituitary–testicular axis, and how its effects are modulated by other extratesticular hormones and local testicular factors.

Effect of luteinizing hormone and vasopressin on ovarian ascorbic acid

1960 ◽  
Vol 199 (5) ◽  
pp. 847-850 ◽  
Author(s):  
S. M. McCann ◽  
S. Taleisnik
Keyword(s):  
Ascorbic Acid ◽  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Body Fluids ◽  
Weight Basis ◽  
Ovarian Vein ◽  
Adult Rats ◽  
Vasopressin Release ◽  
Stimulating Hormone

Luteinizing hormone (LH) depleted ovarian ascorbic acid of immature or adult rats pretreated with gonadotrophins, the former animals being more sensitive than the latter. Follicle-stimulating hormone, luteotrophin and adrenocorticotrophin had minimal or o activity in this assay, whereas vasopressin but not oxytocin had appreciable activity. Vasopressin was more active in the adult rats. If the doses were expressed on a weight basis, vasopressin was actually more potent than the LH standard in the adults; however, endogenous vasopressin release did not deplete ovarian ascorbic acid. The activity of both LH and vasopressin was either not affected or affected to the same degree by hypophysectomy. Retrograde injection of vasopressin into the ovarian vein showed that the action of vasopressin was a direct one on the ovary. Vasopressin does not interfere with the assay of LH in body fluids by this technique.

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