Catecholamines and ascorbic acid as stimulators of bovine ovarian oxytocin secretion

1987 ◽  
Vol 114 (3) ◽  
pp. 423-430 ◽  
Author(s):  
M. R. Luck ◽  
B. Jungclas
Keyword(s):  
Ascorbic Acid ◽  
Granulosa Cells ◽  
Time Course ◽  
Culture Medium ◽  
Stimulatory Action ◽  
Variable Effect ◽  
Progesterone Secretion ◽  
Agonistic Activity ◽  
Cells Cultured ◽  
Stimulation Of

ABSTRACT The effects of catecholamines and ascorbic acid on cultured bovine granulosa cells have been examined to assess their possible role in the initiation and maintenance of luteal oxytocin secretion. The actions of these agents have also been compared with the previously reported ability of follicular theca tissue to enhance oxytocin secretion. Using granulosa cells cultured in serum-supplemented medium, we observed a highly significant enhancement of oxytocin secretion in the presence of adrenaline and noradrenaline, particularly over the concentration range 1–10 μmol/l. This effect was accompanied by smaller and less consistent changes in progesterone secretion and did not involve any change in the time-course of oxytocin secretion. Acetylcholine was without effect. Ascorbic acid stimulated oxytocin secretion when used alone over a range of concentrations, but was also able to synergize with adrenaline. Lactic acid was ineffective. The stimulation of oxytocin secretion by adrenaline could be blocked by equimolar propranolol, but the stimulation of progesterone was not blocked. Propranolol had a variable effect on the ability of theca tissue to stimulate oxytocin secretion by granulosa cells but the results also suggested the presence of some β-agonistic activity in the culture medium. We conclude, first, that catecholamines may be involved in the regulation of ovarian oxytocin secretion, secondly, that ascorbate may regulate oxytocin secretion through its involvement in the biosynthesis of oxytocin but also through interaction with catecholamines and, thirdly, that the stimulatory action of theca tissue probably does not involve the action of β-agonists. J. Endocr. (1987) 114, 423–430

Effect of tri-iodothyronine on protein turnover in rat hepatocyte primary cultures

1987 ◽  
Vol 113 (2) ◽  
pp. 173-177 ◽  
Author(s):  
G. Gallo ◽  
A. Voci ◽  
P. E. Schwarze ◽  
E. Fugassa
Keyword(s):  
Protein Synthesis ◽  
Protein Turnover ◽  
Culture Medium ◽  
Primary Cultures ◽  
Rat Hepatocytes ◽  
Cellular Proteins ◽  
Cultured Hepatocytes ◽  
Rat Hepatocyte ◽  
Cells Cultured ◽  
Stimulation Of

ABSTRACT The effect of tri-iodothyronine (T3) on protein turnover was studied using primary cultures of rat hepatocytes. Protein synthesis was significantly stimulated in cells cultured for 6 days in the presence of T3 (1 μmol/l). Protein secretion into the culture medium was not affected by the hormone. Breakdown of long-lived proteins, the bulk of cellular proteins which are preferentially degraded through the autophagic lysosomal pathway, was significantly stimulated by the hormone. It is concluded that T3 elicits a general stimulation of protein turnover in cultured hepatocytes. J. Endocr. (1987) 113, 173–177

THE EFFECT OF VARIOUS ACTH EXTRACTS ON THE GONADS

1954 ◽  
Vol 10 (4) ◽  
pp. 291-301 ◽  
Author(s):  
R. W. BRIMBLECOMBE ◽  
I. D. K. HALKERSTON ◽  
M. REISS
Keyword(s):  
Ascorbic Acid ◽  
Female Rats ◽  
Male Rats ◽  
Stimulatory Action ◽  
Follicular Maturation ◽  
Accessory Sex Organs ◽  
Stimulation Of

SUMMARY ACTH extracts showing inhibition of the stimulatory action of PMS on follicular maturation in infantile female rats and slight stimulation of the growth of the testes and accessory sex organs in infantile male rats and day-old chicks have been investigated. The action of these extracts on the gonads was found to be independent of the adrenal ascorbic acid depleting principle, as ACTH fractions free from inhibitory or stimulatory influence on the gonads could be prepared. The nature of the factor described is discussed.

Porcine granulosa cells in suspension culture. II. Luteinization and hCG responsiveness

1981 ◽  
Vol 240 (6) ◽  
pp. E622-E629 ◽  
Author(s):  
A. R. LaBarbera ◽  
R. J. Ryan
Keyword(s):  
Adenylate Cyclase ◽  
Granulosa Cells ◽  
Culture Medium ◽  
Cultured Cells ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Short Term ◽  
Progesterone Secretion ◽  
Porcine Granulosa Cells ◽  
Ovine Prolactin

Granulosa cells from small follicles were cultured as suspensions in spinner flasks for 10 days in the absence or presence of follicle-stimulating hormone (FSH). With or without FSH, the cultured cells ultrastructurally resembled luteinized cells to different degrees. FSH increased progesterone accumulation in the culture medium. Ovine prolactin potentiated the effect of FSH in terms of the quantity of progesterone produced and the duration of accumulation. FSH increased acute human chorionic gonadotropin (hCG)-responsive progesterone secretion in short-term incubations of cultured granulosa cells. Responsiveness of FSH-cultured cells was maximal at day 4; that of control cultured cells was maximal at day 6. Adenylate cyclase activity of homogenates of cells cultured for 4, 6, or 8 days was measured. FSH induced in cultured cells an hCG sensitivity of the adenylate cyclase enzyme. These results indicate that FSH induced hCG-responsive progesterone secretion and hCG-responsive adenylate cyclase activity that correlate with ultrastructural signs of luteinization and with the previously reported FSH induction of hCG receptors.

Gonadotrophic regulation of prolactin mediated progesterone secretion in vitro

1985 ◽  
Vol 110 (2) ◽  
pp. 251-256 ◽  
Author(s):  
J. Steven Alexander ◽  
Thomas M. Crisp
Keyword(s):  
Granulosa Cells ◽  
In Vitro Model ◽  
Fold Increase ◽  
Model System ◽  
Regulatory Mechanisms ◽  
Progesterone Secretion ◽  
Vitro Model ◽  
Dose Dependent ◽  
Cells Cultured

Abstract. The effects of preincubating rat granulosa cells with FSH, LH, and Prl on subsequent Prl mediated progesterone secretion were investigated. Granulosa cells were isolated from ovarian follicles 50 h after injection of 5 IU PMSG and were then plated on poly-l-lysine coated coverslips in serum supplemented medium. Cells were preincubated for 24 h in the absence of hormones (control) or with the addition of either 0.25, 2.5, 25 ng/ml rat FSH or rat LH, or 1 μg/ml rat Prl. Following the preincubation period, cells were maintained for an additional 6 or 8 days in the presence or absence of 1 μg/ml Prl. When cells were preincubated with FSH or LH, only the two higher concentrations (2.5 and 25 ng/ml) stimulated significantly more progesterone secretion than control cultures during the 24 h preincubation period. For each series of preincubations, cells cultured for 6 or 8 days in the presence of Prl secreted significantly more progesterone at each day of culture than cells cultured without Prl. Cells preincubated and cultured with Prl secreted only 3–7-fold more progesterone than cells preincubated in control medium and then cultured with Prl. Preincubation with FSH or LH promoted a 20–45-fold increase in Prl mediated progesterone secretion compared to control preincubation cultures that also subsequently were cultured with Prl. The magnitude of Prl mediated progesterone secretion observed through 6 days of culturing was dose dependent on the preincubation concentration of FSH or LH. The establishment of an in vitro model system in which gonadotrophins enhance the responsiveness of granulosa cells to Prl in serum supplemented medium provides the opportunity for study of the regulatory mechanisms involved with the induction and maintenance of such responsiveness.

Stimulation of progesterone secretion by recombinant follistatin-288 in human granulosa cells.

Endocrinology ◽  
1993 ◽  
Vol 132 (4) ◽  
pp. 1750-1756 ◽  
Author(s):  
W Li ◽  
S Khorasheh ◽  
B H Yuen ◽  
N Ling ◽  
P C Leung
Keyword(s):  
Granulosa Cells ◽  
Human Granulosa Cells ◽  
Progesterone Secretion ◽  
Stimulation Of

The effects of phospholipase C on oestradiol and progesterone secretion in porcine granulosa cells cultured in vitro

2019 ◽  
Vol 54 (9) ◽  
pp. 1236-1243 ◽  
Author(s):  
Huali Chen ◽  
Youfu Yang ◽  
Youlin Wang ◽  
Yamei He ◽  
Jiaxin Duan ◽  
...  
Keyword(s):  
Phospholipase C ◽  
Granulosa Cells ◽  
Progesterone Secretion ◽  
Porcine Granulosa Cells ◽  
Cells Cultured

DIRECT STIMULATION OF BOVINE OVARIAN PROGESTERONE SECRETION BY LOW CONCENTRATIONS OF a-INTERFERON

1992 ◽  
Vol 135 (2) ◽  
pp. R5-R8 ◽  
Author(s):  
M.R. Luck ◽  
J.A Shale ◽  
J.H. Payne
Keyword(s):  
Corpus Luteum ◽  
Granulosa Cells ◽  
Dna Content ◽  
Hormone Secretion ◽  
Direct Stimulation ◽  
Serum Free ◽  
Ovarian Cells ◽  
Progesterone Secretion ◽  
Low Concentrations ◽  
Stimulation Of

ABSTRACT The ruminant conceptus secretes proteins during early pregnancy which maintain the corpus luteum. These trophoblast proteins are related to the αII-interferons and prevent luteolysis indirectly by disrupting the secretion of endometrial prostaglandin. Although trophoblast interferons appear to be largely confined to the uterine lumen, it remains possible that they also act peripherally. This report describes in vitro studies which suggest that interferon may influence hormone secretion by the ovary directly. The study employed i) a well defined serum-free culture model in which bovine granulosa cells secrete the luteal hormones progesterone and oxytocin, and ii) serum-free and serum-supplemented cultures of cells from early CL. Dose-response experiments were performed using bovine recombinant α-interferon (brIFN). Progesterone and oxytocin secretions were measured over 4-5 days of culture and DNA content was also determined. Low concentrations of brIFN (10−15 mol/l to 10−11 mol/l) stimulated progesterone secretion by granulosa cells by up to three fold, without significantly affecting oxytocin concentrations or culture DNA content. Concentrations of 10−10 mol/l to 10−7 mol/l suppressed progesterone secretion in a log dose-related manner (r=0.97) with evidence of toxicity (lower oxytocin concentrations and significantly reduced DNA compared with controls). Progesterone secretion by luteal cells in serum-free culture was stimulated in the presence of 10−15 mol/l brIFN, whilst high concentrations again caused inhibition. The data show that ovarian cells can respond directly to low concentrations of interferon-like proteins. They also demonstrate an inhibition by high doses which may mask the stimulatory effect in this model. The data suggest that the early corpus luteum may be directly influenced by α-interferon. A stimulation of progesterone, but not of oxytocin, secretion from ovarian cells would be consistent with a role for conceptus proteins in maintaining the corpus luteum of pregnancy.

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