Oestrus in relation to peak oestradiol levels in ovariectomized Galloway cows

2001 ◽  
Vol 72 (2) ◽  
pp. 401-405
Author(s):  
A. O. Darwash ◽  
G. E. Lamming ◽  
L. M. Hicking

AbstractThe objective of the present study was to characterize the variation in oestrous behaviour among ovariectomized cows in response to a measured dose of oestradiol benzoate (OB) . In study 1, nine ovariectomized Galloway cows, approximately 10 years old, were challenged with an intramuscular injection of either 0·25, 0·5 or 1·0 mg of OB. Following this, 0·5 mg OB was chosen as the appropriate dose required to induce oestrous behaviour in ovariectomized Galloway cows. In study 2, nine cows injected with 0·5 mg OB were monitored for oestrous behaviour using KAMAR® heat mount detectors. Blood samples for plasma oestradiol-17β (E2) assay were taken every 4 h between 0 to 72 h and once at 96 h, following OB administration. The plasma E2 concentrations between 0 to 96 h following OB administration differed significantly ( P < 0·001) among cows. The interval to peak E2 concentrations averaged 17·42 (s.e. 2·21) h and the mean peak E2 concentration was 5·86 (s.e. 0·57) ng/l. The mean interval from OB administration until onset of mounting activity was 24·57 (s.e.2·38) h and the duration of oestrus averaged 10·5 (s.e. 1·99) h . In all cows, mounting activity occurred following peak E2 concentrations after an average interval of 7·73 (s.e. 1·84) h. There was no significant association between peak E2 concentrations and the interval to onset of mounting activity or its duration. Since the variation among Galloway cows in the manifestation of behavioural oestrus was independent of systemic E2 concentrations, it implies that there are inherent differences between individuals in the sensitivity of the hypothalamus to physiological E2 thresholds. This may help to explain the incidence of silent ovulation in some animals and the occurrence of overt oestrus associated with follicular activity during the luteal phase of the cycle or during the various stages of pregnancy, in the presence of high plasma progesterone concentrations.

1982 ◽  
Vol 100 (2) ◽  
pp. 279-284 ◽  
Author(s):  
R. C. Arora ◽  
R. S. Pandey

Abstract. Domestic buffaloes were used to characterize the pattern of progesterone, oestradiol-17β, LH and androgen in the systemic circulation following infertile insemination. Concentrations of hormones were measured by RIA in blood samples collected daily or at alternate days following insemination. The concentration of progesterone was lowest on the day of insemination, and increased significantly to a peak level of 4.00 ± 0.60 ng/ml by day 13 post insemination. After day 17, it declined significantly (P < 0.01) to reach low levels by day 21. The concentration of oestradiol-17β was high at the time of insemination and declined significantly (P < 0.01) by day 2 after insemination. It was maintained around the basal level till day 18 with minor peaks in between this period. It again rose significantly (P < 0.01) at subsequent oestrus. The mean level of LH was highest at the time of insemination, and declined significantly (P < 0.01) by day 1 post insemination. It did not vary appreciably till the animal returned to oestrus. The oestrous value of LH and progesterone were negatively correlated (r = −0.77). The androgen level was observed to be high at insemination in 3 out of 5 animals, but the overall pattern of this steroid was inconsistent during the period studied. A high concentration of androgen was recorded in all the animals from day 2–5 before the onset of oestrus.


1997 ◽  
Vol 93 (1) ◽  
pp. 29-34 ◽  
Author(s):  
G. I. Adebayo ◽  
L. Hemeryck ◽  
M. Hall ◽  
D. Gasparro ◽  
M. Sinnott ◽  
...  

1. We undertook a temporal study of external sodium-stimulated lithium efflux (sodium—lithium countertransport) in erythrocytes and blood pressure by measuring these two parameters in three phases of the menstrual cycle (menstrual, midcycle and luteal phases) in 22 healthy, non-medicated females with regular menstrual cycles. Plasma oestradiol and progesterone levels were also determined. 2. Sodium—lithium countertransport activity (activity in 140 mmol/1 external NaCl) in the midcycle phase (0.176 ± 0.017 mmol h−1 l−1 of cells) was lower than in the menstrual (0.192 ± 0.016 mmol h−1 l−1 of cells, P < 0.030) and luteal (0.203 ± 0.018 mmol h−1 l−1 of cells, P < 0.030) phases. The Vmax of the transporter changed similarly but the Km was unaltered. 3. The plasma oestradiol level was 628.9 ± 39.1 pmol/1 in the midcycle phase, higher than in the menstrual (232 ± 18.5 pmol/1, P < 0.001) and luteal (372.5 ± 28.1 pmol/1, P < 0.001) phases. The progesterone level was 28.6 ± 2.1 nmol/1 in the luteal phase, and values were lower in the menstrual (2.5 ± 0.3 nmol/1, P < 0.001) and midcycle (2.8 ± 0.4 nmol/1, P < 0.001) phases. 4. There was no correlation between plasma oestradiol and sodium—lithium countertransport activity or Vmax during the menstrual cycle, but plasma progesterone was positively correlated with sodium—lithium countertransport activity (r = 0.478, P < 0.025, n = 22) and Vmax (r = 0.551, P < 0.045, n = 14) in the luteal phase. 5. Systolic blood pressure did not change significantly during the menstrual cycle. However, the diastolic pressure showed variation similar to that in sodium—lithium countertransport activity/Vmax, its midcycle value of 66.6 ± 1.4 mmHg being lower than that in the luteal (71.6 ± 1.3 mmHg, P < 0.025) and menstrual (70.6 ± 1.4 mmHg, P < 0.025) phases. 6. We conclude that sodium—lithium countertransport activity exhibits catamenial variation. Therefore we suggest, given this observation, that blood sampling for the assessment of the state of activity of the transport system be standardized in relation to a phase of the menstrual cycle in future studies involving females.


1976 ◽  
Vol 56 (1) ◽  
pp. 37-42 ◽  
Author(s):  
R. RAJAMAHENDRAN ◽  
P. C. LAGUË ◽  
R. D. BAKER

Progesterone levels were estimated by radioimmunoassay in blood samples obtained by venipuncture on the day of estrus and every alternate day until the onset of the next estrus in eight cycling dairy heifers. The mean level of progesterone was < 1 ng/ml during the first 2 days of the cycle, increased rapidly over the 4th–12th day period and reached a peak level value of 5.2 ± 1.1 ng/ml on day 14. Thereafter, the level declined rapidly to 2.6 ± 0.6 ng/ml on day 16 and then more gradually to 0.4 ± 0.1 ng/ml on day 21. In the second experiment, eight cycling heifers at diestrus were treated with gonadotrophin (2,000 IU PMSG or 1,000 IU PMSG + 1,000 IU HCG) followed 48 h later by 15 mg prostaglandin (PGF2α). Mid-ventral laparotomies were performed 4 days after the onset of estrus to observe ovarian activity. Progesterone levels were considerably higher in some animals and were slightly higher on the average after gonadotrophin treatments. The number of corpora lutea (CL) in these heifers ranged from 1 to 17. Progesterone levels of three heifers with 4–9 CL did not differ (P > 0.05) from those of three heifers with single CL. Two heifers each with 17 CL had peak progesterone levels of 38.4 and 27.8 ng/ml which were still high (9.6 and 26.5 ng/ml) by day 21. The remaining six heifers had low progesterone levels (< 1 ng/ml) by days 8–14, indicating premature regression of the CL. Thus, progesterone levels were not correlated with the number of CL.


2010 ◽  
Vol 22 (1) ◽  
pp. 379
Author(s):  
H. Kohram ◽  
G. Mohammadi ◽  
E. Dirandeh

This study was done to consider relationships of luteal phase variables (prior to AI) with follicular waves. The estrous cycles of 15 buffaloes were synchronized with 2 i.m. injections of prostaglandin F2α given 11 days apart. The buffaloes were randomly assigned to 1 of 3 treatments. Buffaloes in the control treatment received no treatment, whereas G6 buffalos received a GnRH injection between Day 5 and 7 and G16 buffalos received a GnRH injection between Day 15 and 17 of the estrous cycle (estrus = Day 0). Daily, from estrus Day 0 to the next estrus Day 23, buffaloes had their ovaries scanned by ultrasound. Blood samples were collected by tail following each ultrasound examination from estrus until next estrus (estrus = 0). Concentrations of plasma progesterone were determined by radioimmunoassay kit. The limit of detection of the assay was 0.1 45 ng mL-1 and the intra- and interassay coeffients of variation were 7.4% and 9.2%, respectively. Data were analyzed by using PROC GLM of SAS (SAS Institute, Cary, NC, USA). For comparisons between groups, the 2-sample t-test was used for continuous traits, such as size of CL or hormone concentrations. Prospective comparisons of indices of progesterone indicated that the length of luteal lifespan was longer in 3-wave than in 2-wave buffaloes (P < 0.01). Plasma progesterone concentrations were similar at peak and measured as area under the curve on Day 5 through 17 preceding insemination in 2-wave (5.30 ± 0.40 ng mL-1) and 3-wave buffaloes (5.10 ± 0.20 ng mL-1). Length of the luteal phase (defined as from the day of estrus until the last day on which plasma progesterone remained >2 ng mL-1) was <2 days shorter in 2-wave buffaloes than in 3-wave buffaloes (15.20 ± 0.40 v. 17.10 ± 0.50 d; P < 0.05). In addition, the day of peak progesterone occurred earlier in 2-wave buffaloes (13.50 ± 0.30 v. 15.30 ± 0.70 d; P < 0.05).


2005 ◽  
Vol 91 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Dario Cotesta ◽  
Chiara Caliumi ◽  
Piero Alò ◽  
Luigi Petramala ◽  
Maria Gabriella Reale ◽  
...  

Aims and background The aim of our study was to investigate the plasma chromogranin A (CgA) and adrenomedullin (AM) levels in patients with pheochromocytomas. Methods and study design We collected blood samples for measurement of plasma CgA and AM in 21 patients with pheochromocytomas, 43 healthy subjects and 26 patients with solid non-functioning adrenocortical adenomas. In 11 patients with pheochromocytomas plasma CgA and AM were measured again four weeks after tumor removal. CgA and AM were measured by means of a novel solid-phase two-site immunoradiometric assay based on monoclonal antibodies (CgA-RIA CT, CIS bio international) and by a specific radioimmunoassay (RIA, Phoenix Pharm. Inc.), respectively. Results The mean plasma CgA level (±SD) in patients with pheochromocytomas (204 ± 147.9 ng/mL) was significantly higher (P <0.001) than that in healthy subjects (41.6 ± 10.7 ng/mL) and in patients with non-functioning adrenocortical adenomas (47.3 ± 17.6 ng/mL). The mean plasma AM concentration (±SD) in patients with pheochromocytomas (27.5 ± 10.4 pg/mL) was significantly higher (P <0.001) than that in HS (13.8 ± 4.5 pg/mL) and in patients with non-functioning adrenocortical adenomas (16.6 ± 7.3 pg/mL). Plasma CgA levels correlated with plasma AM levels (r = 0.501; P <0.02) and with plasma metanephrine levels (r = 0.738; P <0.0001) in patients with pheochromocytomas. In 11 patients with pheochromocytomas plasma CgA and AM concentrations significantly decreased after tumor removal (P <0.001 for both). Circulating CgA and AM had a sensitivity of 76.2% and 81%, a specificity of 97.7% and 90.7%, and an accuracy of 91% and 88%, respectively. Conclusion This study demonstrates that circulating CgA and AM levels are increased in pheochromocytoma patients compared with healthy subjects and patients with non-functioning adrenocortical adenomas. Moreover, at the time of diagnosis plasma CgA levels correlated with plasma AM levels and with plasma metanephrine levels in all patients with pheochromocytomas. In conclusion, plasma CgA and AM concentrations may represent additional biochemical parameters for clinical monitoring of patients with pheochromocytomas.


2011 ◽  
Vol 35 (4) ◽  
pp. 817-825
Author(s):  
José Nélio de Sousa Sales ◽  
Lilian Mara Kirsch Dias ◽  
Celso Rodrigues Franci ◽  
Alexandro Aluísio Rocha ◽  
Guilherme Gastão Cardoso ◽  
...  

Two experiments were conducted to evaluate the effect of the intramuscular injection of betacarotene associated to tocopherol on the plasma concentration progesterone of superovulated Holstein heifers (experiment 1) and in crossbred (Bos taurus x Bos indicus) heifers submitted to fixed-time embryo transfer (FTET, experiment 2). In experiment 1, after estrus synchronization and superovulation animals were inseminated 12 and 24 hours after estrus onset and embryos flushed 7 days later. Heifers were allocated randomly to one of three treatments: Control; T800 (800 mg of betacarotene plus 500 mg of tocopherol) and T1200 (1,200 mg of betacarotene plus 750 mg of tocopherol). The treatments were given on the day of ear implant placement and repeated on the first day of superovulation. Blood samples were collected on D0, D5, D9, D12 and D16. In experiment 2, treatments were imposed at intravaginal device insertion (D0). The same experimental design, as in experiment 1, was used. Blood samples were collected on D17 (embryos implanted) for progesterone determination by radioimmunoassay. In experiment 1, average plasma progesterone concentrations after corpora lutea formation (D12 plus D16 means) were 13.7±1.8 ng/ml, 14.5±2.3 ng/ml and 10.8±2.3 ng/ml for control, T800 and T1200, respectively, and did not differ (P=0.44). In experiment 2, progesterone concentrations on D17 in Control (8.88±0.57 ng/ml), T800 (7.48±0.64 ng/ml) and T1200 (5.90±1.33 ng/ml) groups were similar (P=0.11). Results indicate that the supplemental betacarotene and tocopherol injections did not influence peripheral progesterone concentrations in superovulated Holstein donors and crossbreed recipients heifers.


1971 ◽  
Vol 68 (3) ◽  
pp. 502-512 ◽  
Author(s):  
Elof D. B. Johansson ◽  
Leif Wide ◽  
Carl Gemzell

ABSTRACT The plasma levels of luteinizing hormone (LH) and progesterone and the urinary excretion of LH and oestrogens were measured during the normal menstrual cycle of 22 young and healthy women. A total of 42 cycles were investigated. The urinary excretion of total oestrogens increased during several days before the rise of LH in the urine. The day of maximum excretion of LH and total oestrogens coincided during the midcycle period. The mid-cyclic rise in LH was found to occur on the same day in the plasma and urine and the days of maximum values coincided in 11 out of 16 cycles. In 5 cycles the maximum level was reached one day later in the urine. The plasma levels of progesterone started to increase during the LH and oestrogen peaks. The days for maximum levels of progesterone coincided with the second peak of urinary oestrogens. The levels of progesterone in the plasma reached values above 10 ng per ml in all normal cycles. The plasma levels of progesterone were below 1 ng per ml plasma when menstrual bleeding started. The length of the luteal phase was 14.4 ± 1.1 (s) days. The sum of daily urinary excretion of total oestrogens and the sum of the daily plasma progesterone levels varied within 15 per cent of the mean in five out of six women studied during more than two cycles. The variation in values for the sums of daily oestrogen excretion and plasma progesterone levels was considerably larger between menstrual cycles of different women than between menstrual cycles of the same woman.


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.


1984 ◽  
Vol 38 (1) ◽  
pp. 83-89 ◽  
Author(s):  
E. A. Amoah ◽  
M. J. Bryant

ABSTRACTThirty-six British Saanen female kids, born between either 20 March and 6 April (E) or 10 April and 16 June (L), were reared under three different patterns of lighting — a constant 18-h light: 6-h dark (C); or a weekly step-wise reduction from 18-h to 10-h light: 14-h dark over 10 weeks, commencing at either 6 (R6) or 10 (R10) weeks of age. Vasectomized males were used to test for oestrus; blood samples were collected to determine plasma progesterone concentration. Thirty-three goats attained puberty; all but two kids showed oestrus at first ovulation. The mean ( ± s.d.) age and live weight at puberty were 174·6 (± 4·1) and 141·7 (± 4·3) days (P < 0·001), and 28·6 (± 0·9) and 22·8 (± 1·0) kg (P < 0·001), for E and L treatments, respectively. For R6, R10 and C treatments, the ages and weights wer e 151·6 (± 4·7), 160·4 (± 5·2) and 164·7 (± 4·9) days (NS), respectively, and 24·5 (± 1·1), 25·3 (± 1·2) and 27·8 (± 1·1) kg (NS), respectively. A significant date of birth × lighting-pattern treatment interaction was found for date at puberty (P < 0·001), with puberty occurring earlier for E than L kids only when a reduction in daylength occurred. Puberty occurred earlier on R6 than R10 treatments only for L kids.


1987 ◽  
Vol 112 (1) ◽  
pp. 77-85 ◽  
Author(s):  
R. G. Glencross

ABSTRACT To stimulate a follicular-phase pattern of pulsatile LH release, gonadotrophin-releasing hormone (GnRH; 5 μg) was infused (i.v.) hourly into heifers for periods of 5–11 days during the luteal phase of the oestrous cycle, and also when plasma progesterone levels were increased artificially by means of a progesterone-releasing intravaginal device. Plasma oestradiol-17β concentrations increased from basal (EEE 2·5 pmol/l) to preovulatory peak levels (20–30 pmol/l) during the first 3 days of GnRH treatment. They were maintained at these values before returning to basal levels within 24 h of cessation of infusion. This response occurred regardless of the source of progesterone (endogenous or administered). Follicular development was observed by ovarian palpation (per rectum) in some heifers at the time of maximum secretion of oestradiol-17β. There was no detectable cervical mucus secretion or oestrous behaviour during these periods of high oestradiol-17β levels and ovulation did not occur. Treatment with GnRH did not affect plasma progesterone concentrations or oestrous cycle length. The study shows that oestradiol-17β secretion and follicular development (and the accompanying oestrus and ovulation) are suppressed during the luteal phase of the cycle by high concentrations of plasma progesterone, and provides strong indirect evidence that such inhibition is associated with a reduction in the pulse frequency of LH release. J. Endocr. (1987) 112, 77–85


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