Peripheral and ovarian IGF-I concentrations during the ovine oestrous cycle

1996 ◽  
Vol 148 (2) ◽  
pp. 281-289 ◽  
Author(s):  
B R Leeuwenberg ◽  
N L Hudson ◽  
L G Moore ◽  
P R Hurst ◽  
K P McNatty
Keyword(s):  
Follicular Fluid ◽  
Venous Blood ◽  
Oestrous Cycle ◽  
Corpora Lutea ◽  
Dominant Follicle ◽  
Peripheral Plasma ◽  
Igf I ◽  
Left And Right ◽  
Per Se ◽  
Tritiated Amino Acids

Abstract IGF-I was measured by RIA in plasma samples collected 8-hourly for 24 days which included two consecutive preovulatory surges of LH. In a separate study, ovarian venous blood was collected from animals undergoing ovariectomy on day 10 of the oestrous cycle, or 36 h later after being treated with prostaglandin with or without steroid-free bovine follicular fluid. Jugular venous blood samples were collected before, during and after surgery. Follicles were dissected from ovaries of these animals and sorted into categories of small, intermediate and large, non-atretic or atretic, and the follicular fluid was pooled and assayed for IGF-I. From another population of ovaries recovered from the slaughterhouse, granulosa, theca and corpora lutea were isolated, homogenized and assayed for IGF-I. Finally ovarian corpora lutea and granulosa cells were each incubated with tritiated amino acids overnight at 37 °C. Thereafter the tissues and media were sonicated, IGF-I extracted from the supernatant and tritiated IGF-I precipitated using a specific IGF-I antibody. The absence of any significant change in peripheral IGF-I concentrations following ovariectomy and the finding that the ovarian venous IGF-I concentrations (161 ± 10 μg/l) were not significantly different from levels seen in peripheral blood (157 ± 10 μg/l) indicated that the ovary is not a net exporter of IGF-I. However, the ovary does synthesize IGF-I, as evidenced by granulosa and luteal synthesis, but probably not in quantities in excess of that utilized by ovarian tissues per se. Although the plasma IGF-I levels increased around the second preovulatory LH surge, the results overall indicated that the IGF-I concentrations in plasma are not strictly related to any major ovarian event during the oestrous cycle in the sheep. This view is based on the findings that the concentration of IGF-I in follicular fluid was not related to follicular health but correlated with those in peripheral plasma and that the ovarian venous concentrations did not vary between left and right ovaries irrespective of whether the ovaries contained a corpus luteum, dominant follicle or neither. Collectively, these results are consistent with the notion that IGF-I of ovarian origin fulfils an autocrine/paracrine function and does not have an endocrine role. Moreover, the results show that the concentrations of IGF-I in follicular fluid reflect those in peripheral plasma. Journal of Endocrinology (1996) 148, 281–289

Effect of the denervation of porcine ovaries on dexamethasone-induced cyst formation

2013 ◽  
Vol 61 (2) ◽  
pp. 220-233 ◽  
Author(s):  
Barbara Jana ◽  
Anna Kozłowska ◽  
Joanna Wojtkiewicz ◽  
Mariusz Majewski
Keyword(s):  
Neuropeptide Y ◽  
Follicular Fluid ◽  
Peripheral Nerves ◽  
Cyst Formation ◽  
Oestrous Cycle ◽  
Corpora Lutea ◽  
Nerve Fibres ◽  
Ovarian Nerves

Previously, we have shown that the activity of noradrenergic nerve fibres increased and the steroid content changed in porcine ovaries with dexamethasone-(DXM-) induced polycystic status. To better understand the role of the ovarian nerves in the formation of cystic status, the morphology and steroidogenic activity of the ovaries of DXM-treated gilts after denervation of the gonads were investigated in this study. Ovarian denervation was performed on day 3 of the first studied oestrous cycle and then, on days 7–21 of the cycle, DXM was administered. Following neurectomy and DXM treatment, cysts, medium-sized follicles and corpora lutea were not present, while the number of small-sized follicles increased. Denervation and DXM application led to a reduction in the number of dopamine-β-hydroxylase- and/or neuropeptide Y-immunoreactive nerve fibres. The concentrations of progesterone, androstenedione, testosterone and oestradiol-17β in the follicular fluid and/or in the wall of small-sized follicles of the experimental gilts were lower than in the controls. A similar result was demonstrated for P450scc, 3β-HSD and P450arom protein contents in the small follicles. Our data showed that DXM was not able to stimulate the formation of cysts in denervated porcine ovaries, indicating that the ovarian peripheral nerves might participate in the aetiopathogenesis of polycystic status.

scholarly journals Steroidogenic responses of pig corpora lutea to insulin-like growth factor I (IGF-I) throughout the oestrous cycle

Reproduction ◽  
2003 ◽  
pp. 241-249 ◽  
Author(s):  
EA Miller ◽  
Z Ge ◽  
V Hedgpeth ◽  
JE Gadsby
Keyword(s):  
Signal Transduction ◽  
Growth Factor ◽  
Oestrous Cycle ◽  
Corpora Lutea ◽  
Insulin Like Growth Factor ◽  
Luteal Cells ◽  
Factor I ◽  
Progesterone Secretion ◽  
Igf I ◽  
Growth Factor I

This study was designed to investigate the roles of insulin-like growth factor I (IGF-I), IGF-type I receptor (IGF-IR) and IGF-binding proteins (IGFBPs) in regulating progesterone secretion by pig corpora lutea during the oestrous cycle, and the signal transduction pathways involved in mediating the steroidogenic actions of IGF-I. Corpora lutea were collected on days 4, 7, 10, 13 and 15 or 16 of the oestrous cycle, enzyme dissociated and the luteal cells were cultured for 24 h in Medium 199 with IGF-I (0-100 ng ml(-1)), long R(3)-IGF-I (0-100 ng ml(-1)), anti-IGF-I (Sm 1.2B; 0-10 microg ml(-1)), anti-IGF-IR (alphaIR3; 0-2 microg ml(-1)), or IGF-I signal transduction pathway inhibitors (phosphatidylinositol (PI)-3-kinase: 100 nmol Wortmannin l(-1) and 10 micromol LY 294002 l(-1); MAP kinase: 50 micromol PD 98059 l(-1)) to investigate their effects on IGF-I (100 ng ml(-1)) stimulated progesterone secretion. Pig luteal cells displayed dose-dependent responses to IGF-I and long R(3)-IGF-I on days 4 and 7 of the oestrous cycle, but not on days 10-16. There was no difference in the ED(50) or V(max) (maximal response) values between IGF-I and long R(3)-IGF-I. Neither anti-IGF-I nor anti-IGF-IR had significant effects on progesterone secretion, at any dose or day. Wortmannin and LY 294002 blocked IGF-I stimulated progesterone secretion, but PD 98059 was without effect. Finally, IGF-I (6 microg) infused into the ovary on day 7 in vivo significantly increased progesterone secretion within 45 min of infusion. The conclusions of this study are: (1) IGF-I has steroidogenic actions only on 'young' (days 4-7) pig corpora lutea; (2) endogenous IGF-I and IGFBP are insufficient to modulate progesterone secretion in vitro; and (3) the steroidogenic actions of IGF-I are mediated via PI-3-kinase.

Insulin-like growth factor I receptor mRNA and protein expression in pig corpora lutea

Reproduction ◽  
2000 ◽  
pp. 109-114 ◽  
Author(s):  
Z Ge ◽  
WE Nicholson ◽  
DM Plotner ◽  
CE Farin ◽  
JE Gadsby
Keyword(s):  
Growth Factor ◽  
Corpus Luteum ◽  
Oestrous Cycle ◽  
Receptor Protein ◽  
Corpora Lutea ◽  
Western Blots ◽  
Luteal Cells ◽  
Factor I ◽  
Receptor Mrna ◽  
Igf I

Insulin-like growth factor I (IGF-I) is believed to play a luteotrophic role in the pig corpus luteum during the oestrous cycle. Since the actions of IGF-I in target tissues are mediated by the type I IGF receptor, the concentrations of IGF-I receptor mRNA and protein were examined in pig corpora lutea at different stages of the oestrous cycle. Corpora lutea were collected from normally cyclic gilts on days 4, 7, 10, 13, 15 and 16 of the oestrous cycle (n = 4 animals per day). Corpora lutea on days 7, 10 and 13 were dissociated with collagenase, and large and small luteal cell sub-populations were separated by elutriation. Northern and slot blots were used to examine mRNA, and western blots were used to measure the concentrations of IGF-I receptor protein in the pig corpus luteum. On northern blots, luteal IGF-I receptor mRNA was present as a single 11 kb transcript. The slot blots showed that the steady state expression of IGF-I receptor mRNA increased significantly (P < 0.05) from its lowest value on day 4, to reach a maximum on days 13-16. IGF-I receptor mRNA was also expressed to a greater extent in large compared with small luteal cells (P < 0.05). On western blots, IGF-I receptor appeared as a 95 kDa protein band (beta-subunit) and IGF-I receptor protein concentrations were significantly higher (P < 0.05) on days 4-10 than on days 13-16. Finally, large luteal cells appeared to contain more IGF-I receptor protein than the small luteal cells. In conclusion, since IGF-I receptor was detected in the pig corpus luteum, it is a likely target tissue for IGF-I, especially during the early luteal phase. Furthermore, IGF-I receptor was localized primarily on large luteal cells, thus it is hypothesized that IGF-I may play a paracrine role in the pig corpus luteum.

scholarly journals Ovarian function in ewes after treatment with mifepristone early during the oestrous cycle

Reproduction ◽  
2003 ◽  
pp. 205-210 ◽  
Author(s):  
EM Paslay ◽  
U Salli ◽  
F Stormshak ◽  
Keyword(s):  
Ovarian Function ◽  
Venous Blood ◽  
Oestrous Cycle ◽  
Corpora Lutea ◽  
Blood Samples ◽  
Treatment Groups ◽  
Significant Difference ◽  
Preovulatory Follicles ◽  
Prostaglandin F ◽  
The Mean

The aim of this study was to determine whether endogenous progesterone regulates synthesis and secretion of luteal oxytocin. In Expt 1, mature ewes (n = 5 per group) were assigned randomly to control or mifepristone (RU486) treatment groups. Ewes were injected s.c. twice a day with vehicle or 10 mg RU486 on days 5-7 of the oestrous cycle (oestrus = day 0). On day 8, after an i.v. injection with prostaglandin F(2alpha) (250 microg cloprostenol), venous blood samples were collected at frequent intervals to determine plasma oxytocin concentrations. Plasma oxytocin concentrations of RU486-treated ewes were not significantly different from those of control ewes. In Expt 2, ewes were injected s.c. each day with vehicle or 175 mg RU486 on days 2-5 of the oestrous cycle followed by administration of prostaglandin F(2alpha) on day 6. Four of five RU486-treated ewes showed 'split-oestrus' (oestrous behaviour for 36 h and then again at 84-108 h after the onset of initial oestrus). There was no significant difference in mean plasma oxytocin or progesterone concentrations between treatment groups. The mean masses of mature corpora lutea from control and RU486-treated ewes on day 6 of the oestrous cycle did not differ significantly (394.8 +/- 28.8 versus 319.5 +/- 48.3 mg). RU486-treated ewes contained mature corpora lutea, new corpora lutea (two of four ewes) and preovulatory follicles (>or= 10 mm, two of four ewes). The average interoestrous interval for RU486-treated ewes was 9 days more than that for control animals (26.2 +/- 2.9 versus 17 +/- 0.5 days; P < 0.025).

CONCENTRATION OF OESTROGENS AND ANDROGENS IN HUMAN OVARIAN VENOUS PLASMA AND FOLLICULAR FLUID THROUGHOUT THE MENSTRUAL CYCLE

1976 ◽  
Vol 71 (1) ◽  
pp. 77-85 ◽  
Author(s):  
K. P. McNATTY ◽  
D. T. BAIRD ◽  
A. BOLTON ◽  
P. CHAMBERS ◽  
C. S. CORKER ◽  
...  
Keyword(s):  
Menstrual Cycle ◽  
Follicular Fluid ◽  
Venous Blood ◽  
Follicular Phase ◽  
Ovarian Vein ◽  
Preovulatory Follicle ◽  
Peripheral Plasma ◽  
Preovulatory Follicles ◽  
Late Follicular Phase ◽  
Venous Plasma

SUMMARY The concentrations of androstenedione, testosterone, oestrone and oestradiol-17β were measured in peripheral and ovarian venous blood and follicular fluid of women at various stages of the menstrual cycle. The concentration of oestradiol was similar in small follicles (diameter < 8 mm) at all stages of the menstrual cycle and in large follicles (diameter ⩾ 8 mm) except during the mid- and late follicular phase when the concentration reached a peak (∼ 1500 ng/ml). The concentration of androstenedione was lowest in large preovulatory follicles at mid-cycle at a time when the secretion into the ovarian vein was markedly increased. The concentration of testosterone in large follicles (⩾ 8 mm) was unchanged during the follicular phase whereas in small follicles there was a peak at mid-cycle. The rise in the concentration of testosterone and androstenedione at mid-cycle in peripheral plasma may be due to increased secretion by the preovulatory follicle into the ovarian vein. It is suggested that the relatively low concentration of androstenedione in follicular fluid of the preovulatory follicle arises from increased aromatization by granulosa cells in the course of oestrogen synthesis.

Reproduction in Captive Female Brushtail Possums, Trichosurus-Vulpecula

1986 ◽  
Vol 34 (1) ◽  
pp. 47 ◽  
Author(s):  
JD Curlewis ◽  
GM Stone
Keyword(s):  
Luteal Phase ◽  
Oestrous Cycle ◽  
Vaginal Smear ◽  
Early Age ◽  
Corpora Lutea ◽  
Gestation Length ◽  
Left And Right ◽  
The Mean ◽  
Breeding Seasons ◽  
Effect Of Age

Basic reproductive data were collected from a group of wild-caught brushtail possums during three breeding seasons. The mean (�SE) oestrous cycle length, gestation length and interval from removal of pouch young (RPY) to oestrus were 26.3 � 1.46 (n = 39), 17.1 � 0.14 (n = 21) and 9.0 � 0.46 (n = 41) days respectively, agreeing closely with previously published reports. Sperm were first observed in the vaginal smear on days 0 and 1 of the cycle in mated animals, but 27% of matings did not result in the production of a neonate. There was no effect of age of pouch young on the interval between RPY and oestrus but the incidence of mating was greater when pouch young were removed at an early age. In 25 animals examined during an oestrous cycle corpora lutea or Graafian follicles were unequally distributed between left and right ovaries. During the course of the study, four animals were identified in which oestrus was not followed by a luteal phase.

Effect of active immunization against the amino-terminal peptide (alpha N) of the alpha 43 kDa subunit of inhibin (alpha 43) on fertility of ewes

1994 ◽  
Vol 6 (2) ◽  
pp. 265 ◽  
Author(s):  
JK Findlay ◽  
DL Russell ◽  
B Doughton ◽  
CG Tsonis ◽  
C Borchers ◽  
...  
Keyword(s):  
Follicular Fluid ◽  
Active Immunization ◽  
Corpora Lutea ◽  
Amino Terminal ◽  
Fertilization Rates ◽  
Peripheral Plasma ◽  
End Of Treatment ◽  
The Mean ◽  
And Control ◽  
Ovulatory Process

Immunization against the amino-terminal peptide (alpha N) of the alpha 43 subunit of inhibin was shown previously to reduce fertility in ewes. The aim of this study was to examine the effects of active immunization of ewes against alpha N on egg recovery and fertilization rates. Ewes were immunized against alpha N immunogen, and were given 800 I.U. of pregnant mare's serum gonadotrophin at the end of treatment with intravaginal progesterone to synchronize the oestrous cycles. Control ewes received adjuvant only. The ewes were run with fertile rams, and 4 days after withdrawal of the progesterone device the oviducts were flushed to recover eggs and luteal structures on the ovaries were recorded. Eggs were recovered from 17/19 (90%) control ewes compared with 4/16 treated ewes (25%) (P < 0.01), and the egg recovery rates were 76% (45/59) and 17% (7/42) respectively (P < 0.001). The mean number of corpora lutea (CL) per ewe were similar (3.1 +/- 1.4 v. 2.6 +/- 1.0) but several CL in the treated ewes did not appear to have ruptured, and 2 treated ewes had cystic follicles and no CL. There were no apparent differences in either the fertilization rates or the stages of development of fertilized eggs between treated and control ewes. Antibody binding levels in follicular fluid were approximately half those found in peripheral plasma. It is concluded that immunization of ewes against alpha N leads to lowered fertility by suppressing ovulation, implicating alpha N in the normal ovulatory process.

PROGESTERONE CONCENTRATION IN THE PERIPHERAL PLASMA OF SHEEP DURING THE OESTROUS CYCLE

1969 ◽  
Vol 45 (3) ◽  
pp. 459-469 ◽  
Author(s):  
G. D. THORBURN ◽  
J. M. BASSETT ◽  
I. D. SMITH
Keyword(s):  
Thin Layer ◽  
Luteal Phase ◽  
Jugular Vein ◽  
Oestrous Cycle ◽  
Corpora Lutea ◽  
Progesterone Concentration ◽  
Plasma Progesterone ◽  
Peripheral Plasma ◽  
Layer Chromatography ◽  
Pregnant Mare Serum Gonadotrophin

SUMMARY Using a protein-binding technique, progesterone concentrations in peripheral plasma (jugular vein) were measured throughout the oestrous cycle of 24 ewes. Examination of the specificity of the method by thin-layer chromatography indicated that interference from other steroids was not significant in sheep plasma. During the first 4 days of the cycle (days 0–3), plasma progesterone concentrations were below 0·4 ng./ml., increasing to a mean level of 1·5–2·5 ng./ml. between days 4 and 9, and remaining at this level for approximately 5 days, before declining rapidly on days 14 and 15 to reach a low level on the day before oestrus. The progesterone concentration on the day of oestrus was extremely low (0·1 ng./ml.), and was of the same order as that found in the plasma of wethers and anoestrous or ovariectomized ewes. Three ewes, superovulated with pregnant mare serum gonadotrophin, showed marked elevation of peripheral progesterone concentration during the luteal phase of the cycle, the concentration being proportional to the number of corpora lutea formed.

DISTRIBUTION OF OESTRONE AND OESTRADIOL-17β IN SOW OVARIES

1963 ◽  
Vol 44 (4) ◽  
pp. 529-535 ◽  
Author(s):  
Torleiv Lunaas
Keyword(s):  
Follicular Fluid ◽  
Luteal Phase ◽  
Follicular Phase ◽  
Oestrous Cycle ◽  
Corpora Lutea ◽  
Luteal Tissue ◽  
Low Levels ◽  
The Absolute ◽  
Residual Tissue ◽  
Highly Correlated

ABSTRACT The contents of oestrone and oestradiol-17β were estimated in component parts of sow ovaries representative of the follicular and luteal phase of the oestrous cycle and also in whole juvenile ovaries. The values obtained of the sum total oestrone and oestradiol-17β in the follicular fluid and in the corresponding residual tissue were highly correlated. The proportions of oestradiol-17β tended to be larger in the follicular fluid than in the tissue (mean percentage: 84.3 and 69.6 respectively). In ovaries from the luteal phase of the oestrous cycle the oestrogen levels were generally lower than in ovaries from the follicular phase. Whereas no difference was found between the very low levels of oestrone in the corpora lutea and in the remainder of the ovary containing small follicles, the levels of oestradiol-17β differed significantly, being lower in the luteal tissue. Within each category of ovaries the absolute levels of the oestrogens were very variable. The results are discussed in relation to the pattern of urinary oestrone excretion in the sow during the oestrous cycle.

Sign in / Sign up

Export Citation Format

Share Document