THE SOURCE OF OVARIAN OESTRADIOL AND ANDROSTENEDIONE IN THE SHEEP DURING THE LUTEAL PHASE

1976 ◽  
Vol 83 (2) ◽  
pp. 402-409 ◽  
Author(s):  
D. T. Baird ◽  
R. J. Scaramuzzi

ABSTRACT The secretion of oestradiol and androstenedione was investigated in sheep by cannulating both ovarian veins in situ. The mean ovarian blood flow (ml/min ± se) was significantly higher on the side containing the corpus luteum (7.67 ± 1.36) than on the contralateral side (4.93 ± 0.85). The mean secretion (ng/min ± se) of oestradiol (1.09 ± 0.36) and androstenedione (1.52 ± 0.16) was higher on the side containing at least one large follicle (diameter > 4 mm) than on the contralateral side (0.19 ± 0.05 and 0.62 ± 0.21, respectively). The secretion of oestradiol was unchanged following enucleation of the corpus luteum but fell to very low levels (0.062 ± 0.022 ng/min) after enucleation of follicles diameter > 4 mm. The secretion of androstenedione fell significantly after enucleation of both corpus luteum and large follicles. These results suggest that during the luteal phase in the sheep oestradiol is secreted virtually exclusively by the largest non-atretic Graafian follicle. Androstenedione in contrast arises from both follicle, corpus luteum and possibly stroma.

1967 ◽  
Vol 55 (1) ◽  
pp. 91-96 ◽  
Author(s):  
Benno Runnebaum ◽  
Josef Zander

ABSTRACT Progesterone was determined and identified in human peripheral blood during the preovulatory period of the menstrual cycle, by combined isotope derivative and recrystallization analysis. The mean concentration of progesterone in 1.095 ml of plasma obtained 9 days before ovulation was 0.084 μg/100 ml. However, the mean concentration of progesterone in 1.122 ml of plasma obtained 4 days before ovulation was 0.279 μg/100 ml. These data demonstrate a source of progesterone secretion other than the corpus luteum. The higher plasma-progesterone concentration 4 days before ovulation may indicate progesterone secretion of the ripening Graafian follicle of the ovary.


1970 ◽  
Vol 63 (4) ◽  
pp. 705-716 ◽  
Author(s):  
U. Larsson-Cohn ◽  
E. D. B. Johansson ◽  
L. Wide ◽  
C. Gemzell

ABSTRACT Daily determinations of the plasma level of progesterone and the urinary excretion of luteinizing hormone (LH) and total oestrogens were performed in 6 subjects during one control cycle, immediately followed by three cycles of daily treatment with 0.5 mg of chlormadinone acetate continuously. The control cycles were ovulatory according to the parameters investigated. Two of the women showed a normal LH excretion pattern in all treatment cycles. The four other subjects also had periodical variations in the LH excretion but no distinct midcycle peaks occurred. The mean oestrogen excretion was increased in all three treatment cycles but the difference was satistically significant only in the last two cycles. Compared with the treatment cycles, the sum of progesterone values was significantly decreased in the first two cycles. Chlormadinone acetate in this dose had no thermogenic effect. Three of the subjects showed bleeding irregularities which had no clear connection with the hormone variations measured in the study. It is suggested that the low levels of progesterone might be due to a defective corpus luteum function.


2020 ◽  
Vol 32 (2) ◽  
pp. 191
Author(s):  
M. Pastorello ◽  
M. O. Gastal ◽  
G. K. Piquini ◽  
D. B. Godoi ◽  
E. L. Gastal

The mare, compared to other livestock, has the shortest interval from partum to the first ovulation. In monovulatory species, the follicle deviation process in a wave is characterised by the continued growth of the dominant follicle (DF) and regression of the subordinate follicle. Although follicle diameter deviation, a key event of follicle selection, has been investigated during the oestrous and menstrual cycles, the occurrence of this phenomenon before the first postpartum ovulation seems to be unclear in all species. This study aimed to compare the follicular dynamics and gonadotropin profiles around the follicle diameter deviation day in postpartum lactating (PP Lactating; n=24) versus non-postpartum cycling (NPP Cycling; n=15) mares. On the day of parturition, every PP Lactating mare was paired with an NPP Cycling mare, and ovarian follicles (>4mm) were tracked daily by transrectal ultrasonography, and blood samples were collected. Data were analysed in the PP Lactating group according to the length of the partum-ovulation interval (POI; ≤22 and >22 days) and the postpartum interovulatory interval (PPIOI), and in the NPP Cycling group during two interovulatory intervals (1st and 2nd IOI). In addition, regardless of group, all four intervals were compared. We performed the FSH and LH assays using radioimmunoassay. Ovarian and hormonal parameters were analysed using ANOVA for sequential data. The day and diameter of the DF at the deviation (overall mean: 14.9±2.5 days; 21.7±0.4mm, respectively) were not different (P>0.05) between PP Lactating and NPP Cycling mares. However, when considering the length of POI, follicle deviation occurred 4.4±0.8 days earlier (P<0.001) in mares with POI ≤ 22 days than in mares with POI>22 days. No difference was found between PP Lactating and NPP Cycling mares within and between groups for the intervals from deviation to maximum diameter of the DF (10.4±0.4 days), for the intervals from deviation to ovulation (12.1±0.5 days), or for the growth rates of the DF from deviation to maximum diameter (2.6±0.1mm per day). The growth rate of the DF from deviation to ovulation (2.4±0.1mm per day) did not differ between PP Lactating and NNP Cycling mares; however, this growth rate was lower (P<0.03) in the POI, PPIOI, and 1st IOI compared with the 2nd IOI. The mean diameter of the DF around deviation (days −3 to 3; 22.5±0.3mm), and systemic FSH (days −4 to 4; 10.3±0.2ngmL−1) were not different between PP Lactating and NPP Cycling mares. Level of LH was lower (P<0.0001) around deviation (days −4 to 4) in the PP Lactating (0.7±0.0ngmL−1) versus the NPP Cycling mares (1.8±0.1ngmL−1). Results demonstrated that a partum effect occurs only on the day of deviation in mares during the foal heat (POI ≤ 22 days) and that low levels of LH during both intervals in PP Lactating mares were not detrimental to prevent ovulation.


1989 ◽  
Vol 123 (2) ◽  
pp. 181-188 ◽  
Author(s):  
G. E. Mann ◽  
A. S. McNeilly ◽  
D. T. Baird

ABSTRACT The source of inhibin secretion by the ovary in the sheep at different stages of the oestrous cycle was investigated by in-vivo cannulation of the ovarian veins. Twenty-four Scottish Blackface ewes were allocated to four groups of six ewes, i.e. those operated on during the luteal phase (day 10), and those operated on during the follicular phase 24–30, 36 and 60 h following an injection of 125 μg cloprostenol on day 10 of the luteal phase. Samples of jugular and timed ovarian venous blood were collected under anaesthesia before and after enucleation of the corpus luteum. Ovaries were then removed and follicles dissected out. Following injection of cloprostenol, luteal regression occurred as indicated by a fall in the secretion of progesterone. The concentration of inhibin in jugular venous plasma and its ovarian secretion rate were similar at all stages of the follicular phase and during the luteal phase. In contrast, the secretion rate of oestradiol rose from 2·68 ±0·73 pmol/min during the luteal phase to 8·70± 2·24 pmol/min 24 h after injection of cloprostenol (P<0·05). Following enucleation of the corpus luteum the secretion rate of progesterone fell from 809 ± 270 pmol/min to 86 ± 30 pmol/min (P<0·001). There was also a smaller, artifactual fall in the secretion rate of oestradiol following enucleation of the corpus luteum, which was of similar size to a fall seen in the secretion rate of inhibin. This resulted in a significant (P<0·001) fall in the ratio of progesterone to inhibin, while the oestradiol to inhibin ratio remained unchanged. The secretion rate of inhibin from ovaries containing luteal tissue was similar to that from the contralateral side without luteal tissue (1·41±0·30 compared with 1·32±0·30 ng/min), while ovaries with large antral follicles secreted significantly (P< 0·001) more inhibin than those with no follicles ≥3 mm (2·28 ± 0·36 compared with 0·25 ±0·06 ng/min). From these results we conclude that, in the sheep, large antral follicles are responsible for most, if not all, the secretion of inhibin by the ovary at all stages of the oestrous cycle, and that the corpus luteum secretes little or no immunoactive or bioactive inhibin. Due to the fact that, unlike inhibin, the secretion rate of oestradiol rises during the follicular phase of the cycle, when the concentration of FSH is suppressed, it seems likely that oestradiol rather than inhibin is the major ovarian factor modulating the change in FSH secretion seen at this stage of the oestrous cycle. Journal of Endocrinology (1989) 123, 181–188


1975 ◽  
Vol 79 (2) ◽  
pp. 329-336 ◽  
Author(s):  
F. Lehmann ◽  
I. Just-Nastansky ◽  
B. Behrendt ◽  
P.-J. Czygan ◽  
G. Bettendorf

ABSTRACT The effect of orally given diethylstilboestroldiphosphate (DES) and 17α-ethinyl-oestradiol-3-methylether (EEM) on plasma progesterone levels was studied. Both compounds were administered for 5 days to 5 women in daily doses of 60 mg (DES) and 30 mg (EEM). The fully informed volunteers were found to have a normal menstrual cycle before the study. The mean corpus luteum phase (corpus luteum phase = days between LH surge and onset of menstruation) of all control cycles lasted 12.8 days. Daily plasma samples were collected for radioimmunoassay (RIA) of progesterone, immunoreactive oestrogens and LH. After a control cycle the first treatment was carried out with DES. The third and the fifth cycle were control cycles again. The EEM-treatment was done in the fourth cycle. Although the effect of the two compounds was different, a dependence of the age of the corpus luteum (CL) could be demonstrated for both. DES-treatment lowered plasma progesterone levels during administration. This effect was only demonstrable if the treatment was begun on the day of the LH-peak. The length of the CL-phase remained unaltered. EEM-treatment if started on the day of the LH surge, suppressed corpus luteum function in the late luteal phase. If the treatment was started later, the effect was less pronounced. The administration of both compounds did not shorten the time between ovulation and the next bleeding. After DES-treatment this interval was not altered. After EEM-treatment the subsequent bleeding was even delayed depending on slowly decreasing levels of plasma oestrogens.


2008 ◽  
Vol 90 (6) ◽  
pp. 2334-2339 ◽  
Author(s):  
Hiroshi Tamura ◽  
Akihisa Takasaki ◽  
Ken Taniguchi ◽  
Aki Matsuoka ◽  
Katsunori Shimamura ◽  
...  

2019 ◽  
Vol 31 (1) ◽  
pp. 185
Author(s):  
A. Murtaza ◽  
M. I. R. Khan ◽  
W. Ahmad ◽  
T. Sohail ◽  
I. Mohsin ◽  
...  

The objective of the study was to reveal the factors associated with variable interval to ovulation following a single dose of prostaglandin F2α (PGF2) in Beetal goats. In experiment 1, the extent of ovulation time was demonstrated after synchronizing Beetal goats (n=38) by using a single injection of PGF2 based on corpus luteum detection by B-mode transrectal ultrasonography. Ovulations were detected every 6h from PGF2 until ovulation. To explore the changes in follicular dynamics, endocrine profiles and behavioural events due to the variation in the interval to ovulation, another set of goats (n=13; experiment 2) were synchronized by a single dose of PGF2 given at random days of the luteal phase. Follicular dynamics were monitored every 12h from PGF2 until ovulation and oestrus was detected by apronized bucks every 6h from PGF2 treatment. Blood sampling (3mL) for oestradiol-17β and progesterone was done every 12h from PGF2 until ovulation and every 2h for LH assay by radioimmunoassay. Data were analysed by Student’s t-test, general linear models, and Pearson coefficient correlation (SPSS, version 20.0, SPSS Inc., Chicago, IL, USA). Results revealed that ovulation time varied from 60 to 96h after PGF2, and 57% of ovulations occurred by 72h after PGF2 (experiment 1). Based on this observation, goats (n=13) in second experiment were retrospectively divided into early and late ovulators (i.e. 72 and 84h following PGF2, respectively). Onset of oestrus, peak oestradiol-17β concentration, and LH surge after PGF2 were first observed in early than late ovulators (P&lt;0.05). The goats having greater follicle diameter and smaller corpus luteum diameter at the time of PGF2 ovulated earlier than late ovulators (5.4±0.2v. 4.3±0.2mm and 10±0.6v. 11.8±0.3mm, respectively; P&lt;0.05). Likewise, plasma progesterone concentration tended to be lower (P=0.087) in early than late ovulators. However, interval from onset of oestrus to peak LH and ovulation, duration of standing oestrus, interval from LH peak to ovulation, diameter and growth rate of preovulatory follicles, and number of ovulations were similar (P&gt;0.05) between early and late ovulators. In conclusion, the size of dominant follicle and corpus luteum at the time of PGF2 determines the interval to ovulation following a single dose of PGF2 during the luteal phase.


1991 ◽  
Vol 70 (6) ◽  
pp. 2656-2662 ◽  
Author(s):  
M. C. Hogan ◽  
D. E. Bebout ◽  
P. D. Wagner

We investigated the effect of increasing hemoglobin- (Hb) O2 affinity on muscle maximal O2 uptake (VO2max) while muscle blood flow, [Hb], HbO2 saturation, and thus O2 delivery (muscle blood flow X arterial O2 content) to the working muscle were kept unchanged from control. VO2max was measured in isolated in situ canine gastrocnemius working maximally (isometric tetanic contractions). The muscles were pump perfused, in alternating order, with either normal blood [O2 half-saturation pressure of hemoglobin (P50) = 32.1 +/- 0.5 (SE) Torr] or blood from dogs that had been fed sodium cyanate (150 mg.kg-1.day-1) for 3-4 wk (P50 = 23.2 +/- 0.9). In both conditions (n = 8) arterial PO2 was set at approximately 200 Torr to fully saturate arterial blood, which thereby produced the same arterial O2 contents, and muscle blood flow was set at 106 ml.100 g-1.min-1, so that O2 delivery in both conditions was the same. VO2max was 11.8 +/- 1.0 ml.min-1.100 g-1 when perfused with the normal blood (control) and was reduced by 17% to 9.8 +/- 0.7 ml.min-1.100 g-1 when perfused with the low-P50 blood (P less than 0.01). Mean muscle effluent venous PO2 was also significantly less (26 +/- 3 vs. 30 +/- 2 Torr; P less than 0.01) in the low-P50 condition, as was an estimate of the capillary driving pressure for O2 diffusion, the mean capillary PO2 (45 +/- 3 vs. 51 +/- 2 Torr). However, the estimated muscle O2 diffusing capacity was not different between conditions.(ABSTRACT TRUNCATED AT 250 WORDS)


1973 ◽  
Vol 74 (4) ◽  
pp. 732-742 ◽  
Author(s):  
William T. K. Bosu ◽  
Elof D. B. Johansson ◽  
Carl Gemzell

ABSTRACT The levels of oestrone (E1)*, oestradiol-17β (E2) and progesterone (P) were determined simultaneously by radioimmunoassay in serial peripheral plasma samples from 11 rhesus monkeys (Macaca mulatta) during ovulatory menstrual cycles. In 3 other monkeys luteectomy was performed on day 20 or 21 of the menstrual cycle. The mean plasma levels of oestradiol-17β predominated over the mean E1 during the follicular phase, but during the luteal phase the E1 and E2 patterns varied widely. Before menstruation, increased or unchanged levels of E1 and E2 were mostly found. The decrease found in a few monkeys never reached the low levels found during the days after the midcycle peak. The plasma levels of progesterone increased from less than 0.2 ng/ml during the follicular phase to maximal values within 3 to 4 days after the midcycle peak of oestradiol-17β. The plasma levels of progesterone decreased to less than 1 ng/ml and remained low for 3 to 5 days before menstruation. In the luteectomized monkeys the plasma levels of P, E1 and E2 fell dramatically within 24 h and vaginal bleeding was detected within 72 h post-operatively. In 2 of the 3 luteectomized monkeys the levels of E1 and E2 increased before the bleeding. The ratio of oestrogens (oestradiol-17β and oestrone) over progesterone changed markedly in favour of the oestrogens during the pre-menstrual period. It is concluded that the patterns of progesterone and oestrogens are divergent during the luteal phase. The maximal levels of progesterone are reached early while the maximal levels of oestrogens are reached later during the luteal phase.


1987 ◽  
Vol 253 (1) ◽  
pp. G26-G32
Author(s):  
R. J. Korthuis ◽  
J. N. Benoit ◽  
P. R. Kvietys ◽  
M. H. Laughlin ◽  
A. E. Taylor ◽  
...  

Intestinal blood flows were measured using the radioactive microsphere technique in anesthetized, fasted (18–24 h) rats 4 wk after administration of streptozotocin (65 mg/kg body wt) or its vehicle. Blood flow was increased along the length of the small bowel in diabetic rats relative to normal animals. In an attempt to define the mechanisms underlying the intestinal hyperemic response to diabetes, we employed an in situ, blood perfused, isolated rat jejunum-ileum preparation. Intestinal blood flow was increased by 37%, while intestinal vascular resistance was reduced by 39% in diabetic rats relative to control animals. Cross-perfusion of control intestinal preparations with arterial blood from diabetic rats produced a 30% increase in blood flow and a 24% reduction in vascular resistance. Increasing plasma osmolarity, plasma glucose concentration, or plasma glucagon concentration in control animals to levels measured in diabetic animals produced reductions in vascular resistance that were qualitatively similar to that seen in the diabetic intestine. Intestinal vascular sensitivity to norepinephrine was assessed by constructing dose-response curves in control anddiabetic animals. The mean ED50 values for norepinephrine were increased in diabetic rats relative to control animals. These results indicate that the intestinal hyperemic response in diabetes may be related to increased levels of circulating vasodilators, including hyperosmolarity and glucagon, and a reduced vascular sensitivity to norepinephrine.


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