scholarly journals Plasma concentrations of prolactin in brushtail possums (Trichosurus vulpecula) in different physiological states

2006 ◽  
Vol 190 (2) ◽  
pp. 295-305 ◽  
Author(s):  
J L Crawford ◽  
B P Thomson ◽  
M F Beaumont ◽  
D C Eckery
Keyword(s):  
Breeding Season ◽  
Post Partum ◽  
Mammalian Species ◽  
Plasma Concentrations ◽  
Oestrous Cycle ◽  
Brushtail Possum ◽  
Blood Samples ◽  
Lh Surge ◽  
Time Determination ◽  
First Time

Prolactin (Prl) has been implicated in reproduction in many mammalian species and is illustrated by the distinctive patterns of secretion during the breeding season, the oestrous cycle and lactation. The recent development of a homologous RIA for measuring the circulating Prl concentrations in brushtail possums has facilitated the reliable measurement of Prl in plasma during different physiological states in this species for the first time. Determination of Prl concentrations during lactation involved the collection of weekly blood samples from eight female possums from the time of parturition through either one or two consecutive lactational cycles. Prl was at baseline levels during early lactation (weeks 0–14 post-partum), and then increased markedly to maximum concentrations at weeks 19–21 before returning to nadir levels at a time coincident with the weaning of pouch young (weeks 23–27). The profile of Prl secretion over the oestrous cycle and in particular at the time of the preovulatory LH surge was obtained from 14 possums during the reproductive cycle, in which preovulatory follicle development and ovulation were monitored by laparoscopy. There was no distinct daily pattern of Prl secretion during the oestrous cycle; however, in 3/4 possums in which a typical preovulatory LH surge was measured, a biphasic preovulatory Prl surge was also observed. The preovulatory Prl surge commenced 2–6 h prior to, and had returned to baseline close to the onset of, the preovulatory LH surge, and a second surge of Prl occurred concomitantly with the delayed preovulatory FSH surge. Seasonality of Prl levels was established from weekly blood samples collected from six barren female possums, and concentrations of Prl were lower during the breeding season compared to the non-breeding season. Additionally, a circadian pattern of Prl secretion was evident in both female and male possums, with Prl levels higher in the morning compared to the afternoon. In conclusion, interpretation of endogenous secretory patterns suggests that Prl may be important during late lactation and at impending ovulation, but the involvement of the circannual rhythm of Prl in the regulation of seasonality in the brushtail possum remains to be determined.

Studies of the oestrous cycle, oestrus and pregnancy in the koala (Phascolarctos cinereus)

Reproduction ◽  
2000 ◽  
pp. 49-57 ◽  
Author(s):  
SD Johnston ◽  
MR McGowan ◽  
P O'Callaghan ◽  
R Cox ◽  
V Nicolson
Keyword(s):  
Luteal Phase ◽  
Post Partum ◽  
Plasma Concentrations ◽  
External Genitalia ◽  
Oestrous Cycle ◽  
Phascolarctos Cinereus ◽  
Pregnant Females ◽  
Peripheral Plasma ◽  
The Mean ◽  
High Concentrations

As an integral part of the development of an artificial insemination programme in the captive koala, female reproductive physiology and behaviour were studied. The oestrous cycle in non-mated and mated koalas was characterized by means of behavioural oestrus, morphology of external genitalia and changes in the peripheral plasma concentrations of oestradiol and progestogen. The mean (+/- SEM) duration of the non-mated oestrous cycle and duration of oestrus in 12 koalas was 32.9 +/- 1.1 (n = 22) and 10.3 +/- 0.9 (n = 24) days, respectively. Although the commencement of oestrous behaviour was associated with increasing or high concentrations of oestradiol, there were no consistent changes in the morphology or appearance of the clitoris, pericloacal region, pouch or mammary teats that could be used to characterize the non-mated cycle. As progestogen concentrations remained at basal values throughout the interoestrous period, non-mated cycles were considered non-luteal and presumed anovulatory. After mating of the 12 koalas, six females gave birth with a mean (+/- SEM) gestation of 34.8 +/- 0.3 days, whereas the remaining six non-parturient females returned to oestrus 49.5 +/- 1. 0 days later. After mating, oestrous behaviour ceased and the progestogen profile showed a significant increase in both pregnant and non-parturient females, indicating that a luteal phase had been induced by the physical act of mating. Progestogen concentrations throughout the luteal phase of the pregnant females were significantly higher than those of non-parturient females. Parturition was associated with a decreasing concentration of progestogen, which was increased above that of basal concentrations until 7 days post partum.

Miniature ponies: 2. Endocrinology of the oestrous cycle

2008 ◽  
Vol 20 (3) ◽  
pp. 386 ◽  
Author(s):  
O. J. Ginther ◽  
M. A. Beg ◽  
A. P. Neves ◽  
R. C. Mattos ◽  
B. P. L. Petrucci ◽  
...  
Keyword(s):  
Maximum Concentration ◽  
Luteal Phase ◽  
Plasma Concentrations ◽  
Oestrous Cycle ◽  
Slow Increase ◽  
Lh Surge ◽  
Ovulatory Follicle ◽  
The Future ◽  
Three Phases

Plasma concentrations of FSH, LH, oestradiol and progesterone were studied daily during 12 interovulatory intervals and 21 periovulatory periods in nine Miniature ponies. The peak of the FSH surge that was temporally associated with emergence of the future ovulatory follicle occurred when the follicle was ~9 mm, compared with a reported diameter of 13 mm in larger breeds. The ovulatory LH surge involved a slow increase between Days 13 and 18 (ovulation = Day 0; 0.6 ± 0.1 ng day–1), a minimal increase or a plateau on Days 18 to 21 (0.04 ± 0.1 ng day–1), and a rapid increase after Day 21 (2.2 ± 0.4 ng day–1; P < 0.0001). The end of the plateau and the beginning of the rapid increase occurred on the day of maximum concentration in the oestradiol preovulatory surge. An unexpected mean increase and decrease in LH occurred (P < 0.04) on Days 5 to 9. Concentrations of oestradiol and progesterone seemed similar to reported results in larger breeds. Results indicated that in Miniature ponies the peak of the FSH surge associated with emergence of the future ovulatory follicle occurred at a smaller diameter of the future ovulatory follicle than in larger breeds, the ovulatory LH surge increased in three phases, and the ovulatory LH surge was followed by an LH increase and decrease during the early luteal phase.

231 EFFECTS OF DIETARY PROPYLENE GLYCOL ON FOLLICULAR FLUID AND OVUM PICK UP IN VITRO EMBRYO PRODUCTION IN GROWTH-RESTRICTED HEIFERS WITH TWO PROFILES OF ANTI-MÜLLERIAN HORMONE

2015 ◽  
Vol 27 (1) ◽  
pp. 205
Author(s):  
G. Gamarra ◽  
C. Ponsart ◽  
S. Lacaze ◽  
B. Le Guienne ◽  
P. Humblot ◽  
...  
Keyword(s):  
Propylene Glycol ◽  
Follicular Fluid ◽  
Plasma Concentrations ◽  
Oestrous Cycle ◽  
Water Control ◽  
Embryo Production ◽  
Blood Samples ◽  
Metabolic Hormones ◽  
In Vitro Embryo Production

Fertility and embryo quality can be improved in cattle by using diets that induce a programmed modulation of circulating insulin concentrations. The aim of this study was to test whether the daily oral administration of propylene glycol (PG) could modify metabolite and hormone plasma and follicular fluid concentrations and improve in vitro embryo production in superovulated growth-restricted heifers (600 g day–1). Sixteen Holstein heifers were grouped according to their pre-experimental anti-Müllerian hormone (AMH) plasma concentrations: low (L = 1–80 pg mL–1; n = 7) or high (H: >150 pg mL–1; n = 9). Heifers received a single daily drench from Day 1 to Day 9 of an oestrous cycle [first cycle, 400 mL of water (control) and second cycle, 400 mL of PG]. Serial jugular blood samples were collected on Day 7 of each cycle to monitor plasma insulin, glucose, and β-hydroxybutyrate (BHB) concentrations in relation to the drench. Blood samples were also collected to measure insulin-like growth factor-1 (IGF1) and progesterone (P4) concentrations on Days 0, 2, 5, 7, and 9 of the oestrous cycle. Follicular fluid was collected on Day 9 to measure insulin and IGF1 concentrations. Ovarian ultrasonography was performed on Days 2 and 5 to count follicles between 2 and 8 mm in diameter and estimate their size. After ovum pickup (OPU) performed following superovulation on Day 5 of the oestrous cycle, oocytes were matured and fertilized in vitro, then embryos were cultured for 7 days. Propylene glycol increased plasma concentrations of insulin and glucose and reduced BHB in both groups of heifers compared with control. It also increased IGF1 concentrations on Days 5 and 7 in AMH L heifers and on Days 2, 5, and 7 in AMH H heifers, and reduced P4 concentrations on Days 5 and 9 of the oestrous cycle in all heifers. In follicular fluid, there was no difference in insulin concentrations between groups, but PG increased IGF1 concentrations in all heifers. In ovaries, PG increased the number of small follicles (2–3 mm) and total follicles on Day 2 of the cycle in all heifers, and medium follicles (4–8 mm) and total follicles on Day 5 in AMH H heifers. Propylene glycol improved the in vitro embryo development rate (total number of embryos/number of fertilized oocytes) in all heifers (AMH L: control, 37.9% v. PG, 50.0%; P < 0.05; AMH H: control, 36.4% v. PG, 48.3%; P < 0.05). In AMH H, the number of grade 1 blastocysts was increased by PG (control, 5.2 ± 1.0 v. PG, 8.9 ± 1.0; P < 0.01), whereas there was no difference between treatments in AMH L heifers (control, 1.9 ± 1.1 v. PG, 3.2 ± 1.1; P > 0.05). These results indicate that short-term oral PG supplementation affects the concentrations of metabolites and metabolic hormones in blood and IGF1 concentrations in follicular fluid. PG administration is effective in improving in vitro embryo production more markedly in heifers with high AMH compared with low AMH endocrine levels.

LUTEINIZING HORMONE AND LUTEINIZING HORMONE RELEASING HORMONE-LIKE IMMUNOREACTIVITY IN THE JUGULAR VENOUS BLOOD OF SHEEP AT VARIOUS STAGES OF THE OESTROUS CYCLE

1976 ◽  
Vol 68 (3) ◽  
pp. 409-417 ◽  
Author(s):  
J. P. FOSTER ◽  
S. L. JEFFCOATE ◽  
D. B. CRIGHTON ◽  
D. T. HOLLAND
Keyword(s):  
Luteinizing Hormone ◽  
Breeding Season ◽  
Venous Blood ◽  
Oestrous Cycle ◽  
Maximal Level ◽  
Blood Samples ◽  
Luteinizing Hormone Releasing Hormone ◽  
Two Samples ◽  
Lh Rh ◽  
Venous Plasma

SUMMARY Luteinizing hormone and LH-RH-like immunoreactivity were measured in the jugular venous plasma of Clun Forest ewes at various stages of the oestrous cycle. Blood samples were collected through jugular venous cannulae every 2 h for at least 20 days from three ewes during the breeding season. The ewes were checked twice daily for oestrus using a vasectomized ram. Plasma LH peaks of apparent height 112–192 ng NIH-LH-S17 equivalents/ml were detected at oestrus with basal levels of 2–15 ng/ml during most of the remainder of the 17-day oestrous cycle. Peaks of LH-RH-like immunoreactivity occurred at various times of the cycle. The apparent maximal level of these peaks was 220 pg/ml compared with basal levels of < 10 pg/ml. Further ewes (two for each group) were sampled at 4 min intervals for 12 h, (1) from onset of oestrus, (2) 36–48 h after onset of oestrus or (3) on day 10 of the oestrous cycle. In the ewes sampled at oestrus, peaks of LH-RH-like immunoreactivity were detected before, during and after the preovulatory LH peak. Those detected after the LH peak were unassociated with any further increases in the plasma LH level. In the ewes sampled 36–48 h after onset of oestrus and on day 10 of the cycle, several peaks of LH-RH-like immunoreactivity unassociated with any increases in the LH level were detected. These peaks, and those detected at oestrus, had durations of only one or two samples, and in some cases reached levels of several ng/ml compared with basal levels of < 10 pg/ml. The significance of these results is discussed.

Circulating blood progesterone is pulsatile throughout the rat oestrous cycle

1987 ◽  
Vol 116 (1) ◽  
pp. 121-128 ◽  
Author(s):  
Ok-Kyong Park ◽  
Victor D. Ramirez
Keyword(s):  
Jugular Vein ◽  
Recovery Period ◽  
Oestrous Cycle ◽  
Female Rats ◽  
Individual Data ◽  
Blood Samples ◽  
Ether Anaesthesia ◽  
Heparinized Saline ◽  
Freely Moving ◽  
First Time

Abstract. In the present experiment, we determined circulating progesterone (P4) levels of intact cycling female rats. A cannula constructed from polyethylene50 tubing containing heparinized saline was inserted into the jugular vein of the rat under light ether anaesthesia and after a 3–6 h recovery period sequential blood samples were withdrawn from unanaesthetized, freely-moving rats. Blood samples (80–100 μl) were collected at 10-min intervals for 6 h and the volume was replaced with saline. Plasma P4 was determined using a specific P4 radioimmunoassay. Four rats in each of three phases of the rat oestrous cycle (E, Dl, D2) were examined. In addition, rats in proestrus were divided into an early (EP, N = 4) and a late (LP, N = 4) proestrous conditions. Individual data were analyzed by PULSAR as adapted for an IBM-PC. P4 was found to fluctuate in a pulsatile mode throughout the rat oestrous cycle. Mean levels of circulating P4 were lowest (38.8 ± 1.7 nmol/l plasma) in EP and highest (122.5 ± 1.3) in Dl. The frequency of P4 pulses was dramatically decreased in Dl (2.50 ± 0.86 pulses/6 h), whereas no difference was found among the other days of the cycle (7.25 ± 0.47 in E, 7.25 ± 0.85 in D2, 5.75 ± 1.31 in EP, and 6.50 ± 1.04 in LP). Interestingly, the amplitude of P4 pulses was significantly lower in EP (14.0 ± 2.91 pmol), whereas no difference was found among other groups. Another group of experimental animals were ovariectomized (N = 4; two with and two without an implant of a silastic capsule of P4) and similarly bled. These animals demonstrated a fairly stable circulating pattern of P4. The present data demonstrate for the first time that P4 in rat blood fluctuates in a pulsatile manner.

276. Sex difference in the effect of cortisol on the LH response of the pituitary to exogenous GnRH in hypothalamo-pituitary disconnected gonadectomised sheep

2005 ◽  
Vol 17 (9) ◽  
pp. 114
Author(s):  
C. A. Stackpole ◽  
I. J. Clarke ◽  
A. I. Turner ◽  
A. J. Tilbrook
Keyword(s):  
Sex Difference ◽  
Breeding Season ◽  
Sex Steroids ◽  
Present Experiment ◽  
Control Period ◽  
Plasma Concentrations ◽  
Saline Infusion ◽  
Sheep Model ◽  
Blood Samples ◽  
Lh Secretion

We have used the hypothalamo-pituitary disconnected (HPD) sheep model to investigate direct pituitary actions of cortisol to suppress LH secretion in response to exogenous GnRH. We previously observed that, during the non-breeding season, treatment with cortisol did not suppress the LH response to GnRH in HPD gonadectomised rams or ewes.1 In the present experiment, we tested the effect of cortisol on the LH response to exogenous GnRH in gonadectomised HPD sheep during the breeding season. Using a cross-over design, HPD gonadectomised Romney Marsh rams (n = 6) and ewes (n = 5) received a saline or cortisol (250 μg/kg/h) infusion for 30 h on each of two days, one week apart. All animals were treated with 125 ng i.v. injections of GnRH every 2 h during a 6h control period preceding the infusion and during the infusion. Jugular blood samples were taken during the control period and the first 6 h and last 6 h of the infusion (over 3 LH pulses). Mean plasma concentrations of LH and LH pulse amplitudes, driven by programmed GnRH injections, were similar in gonadectomised rams and ewes and there were no significant effects of saline infusion between the control periods or the saline infusion in either sex. The amplitude of LH pulses was significantly (P < 0.05) reduced in rams during the first 6 h of the cortisol infusion compared to the control period, but there were no effects of the cortisol infusion in ewes. These data show that, in the absence of sex steroids, there is a sex difference in the mechanism by which cortisol acts at the pituitary to reduce LH secretion in response to exogenous GnRH in HPD gonadectomized sheep during the breeding season. We conclude that the effect of cortisol to reduce secretion of LH involves an action on the pituitary, at least in gonadectomised rams. (1)Stackpole CA, Turner AI, Clarke IJ and Tilbrook AJ (2003) Biology of Reproduction 36(Supplement 1), 288.

Breeding of a Captive Colony of Notomys fuscus Wood Jones (Rodentia : Muridae)

1980 ◽  
Vol 7 (3) ◽  
pp. 379 ◽  
Author(s):  
HJ Aslin ◽  
CHS Watts
Keyword(s):  
Breeding Season ◽  
Vaginal Bleeding ◽  
Post Partum ◽  
Reproductive Rate ◽  
Oestrous Cycle ◽  
Gestation Period ◽  
Pregnant Females ◽  
Delayed Implantation ◽  
Lactating Females

Reproductive data were obtained from a captive colony of N. fuscus over 10 years. Females had an oestrous cycle averaging 7.4 days, and a gestation period averaging 34.3 days. Only three possible instances of post-partum mating were recorded, but. some lactating females returned to oestrus 14-22 days after birth of their young. There was no evidence of delayed implantation due to lactation. Vaginal bleeding occurred in pregnant females 8-17 days before birth. Seventy-four litters were born, litter sizes ranging from one to five, average 2.7. No breeding season was evident. Both sexes were reproductively mature at 70 days old. Comparisons are made with other species of Notomys, and their generally low reproductive rate discussed.

Abstract 164: Specific Point-of-Care Testing of Coagulation in Patients Treated With Non-Vitamin K Antagonist Oral Anticoagulants Part I (SPOCT-NOAC I)

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Florian Härtig ◽  
Andreas Peter ◽  
Charlotte Spencer ◽  
Matthias Ebner ◽  
Christine S Zürn ◽  
...  
Keyword(s):  
Vitamin K ◽  
Point Of Care ◽  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Rapid Assessment ◽  
Plasma Concentrations ◽  
Vitamin K Antagonist ◽  
Point Of Care Testing ◽  
Blood Samples ◽  
First Time

Introduction: Non-vitamin K antagonist oral anticoagulants (NOAC) are increasingly replacing vitamin K antagonists for prevention of thromboembolism in atrial fibrillation (AF) and venous thrombosis. Ischemic stroke rate in NOAC-treated AF-patients is 1-2% per year. Subsequently, stroke physicians face a growing number of NOAC-treated patients with acute stroke. Rapid assessment of coagulation in NOAC-treated patients is vital prior to thrombolysis, but existing point-of-care testing (POCT) is suboptimal. For the first time we evaluate NOAC-specific POCT. Hypothesis: Ecarin clotting time (ECT)- and anti-Xa activity-POCT accurately predict plasma concentrations of dabigatran and apixaban/edoxaban/rivaroxaban. Methods: 80 patients receiving first NOAC-dose and 80 already on NOAC-treatment will be enrolled (N=40 for each NOAC). Subjects receiving other anticoagulants will be excluded. 6 blood samples will be collected from each patient: before drug intake, 30min, 1, 2, and 8h after intake, and before next dose. NOAC-concentrations will be measured by mass spectrometry. Results (preliminary): Until now 138 blood samples of 23 dabigatran-treated patients were analyzed. Dabigatran-concentrations ranged from 0-371ng/mL. ECT-POCT ranged from 20-219s. Pearson’s correlation coefficient showed strong correlation for ECT-POCT and dabigatran-concentrations (r=0.94, p<0.001). Dabigatran-concentrations >50ng/mL (threshold for thrombolysis according to expert recommendation) were detected by ECT-POCT (>50s) with 100% sensitivity and 82% specificity. Baseline-samples not containing any dabigatran yielded normal ECT-POCT. Conclusions: This is the first study evaluating NOAC-specific POCT. Preliminary results show excellent correlation for ECT-POCT and dabigatran; relevant dabigatran-concentrations were detected in 100%. More pioneering results on NOAC-specific POCT will be presented.

scholarly journals Plasma FSH, inhibin A and inhibin isoforms containing pro- and -alphaC during winter anoestrus, spring transition and the breeding season in mares

Reproduction ◽  
2002 ◽  
pp. 535-542 ◽  
Author(s):  
ED Watson ◽  
M Heald ◽  
A Tsigos ◽  
R Leask ◽  
M Steele ◽  
...  
Keyword(s):  
Breeding Season ◽  
Plasma Concentrations ◽  
Oestrous Cycle ◽  
Transitional Period ◽  
Inhibin A ◽  
Cycle Growth ◽  
Preovulatory Follicles ◽  
Spring Transition ◽  
Ovarian Cyclicity ◽  
Follicular Activity

Ten mares were studied from February (winter anoestrus) to their second ovulation in the breeding season to investigate the relationship between resumption of ovarian cyclicity in the spring and circulating concentrations of FSH, inhibin A and inhibin isoforms containing pro- and -alphaC immunoreactivity. An additional four mares were studied during one oestrous cycle. Growth and regression of ovarian follicles were monitored by transrectal ultrasonography. The frequency of blood sampling varied from three times a week to once a day, depending on the follicular activity present. Concentrations of FSH, oestradiol, inhibin A and pro- and -alphaC isoforms were low during deep winter anoestrus when minimal follicular activity was present in the ovaries. During spring transition, an increase in FSH concentration preceded the emergence of each follicular wave. Concentrations of inhibins were significantly higher (P < 0.05) during growth of anovulatory follicles in spring transition than during winter anoestrus. Plasma concentrations of oestradiol and inhibin A were significantly higher (P < 0.001, P < 0.05, respectively) during the growth of preovulatory follicles than during the growth of transitional anovulatory follicles, but concentrations of inhibin pro-alphaC isoforms did not differ between the two types of follicle. During the oestrous cycle, there was a significant inverse relationship (P < 0.001) between concentrations of FSH and the inhibins. Plasma inhibin pro-alphaC isoforms, but not inhibin A, reached a peak on the day of ovulation. The results strongly indicate that FSH regulates growth of spring anovulatory and preovulatory follicles. Inhibins are likely to contribute to negative feedback on the release of FSH from the pituitary gland both during the transitional period and the breeding season in mares.

PLASMA CONCENTRATIONS OF 25-HYDROXY VITAMIN D IN PREGNANT AND LACTATING EWES AND FOETAL AND NEWBORN LAMBS

1978 ◽  
Vol 79 (1) ◽  
pp. 149-150 ◽  
Author(s):  
J.-P. BARLET ◽  
B. ARGEMI ◽  
MARIE-JEANNE DAVICCO ◽  
J. LEFAIVRE
Keyword(s):  
Vitamin D ◽  
Calcium Phosphate ◽  
Carotid Arteries ◽  
Post Partum ◽  
Plasma Concentrations ◽  
Blood Samples ◽  
25 Hydroxy Vitamin D ◽  
Daily Intakes

I.N.R.A., Theix, 63110 Beaumont, France and Groupe Hospitalier de la Timone, 13385 Marseille, France (Received 31 May 1978) Very little information is available concerning interrelationships between maternal and foetal concentrations of 25-hydroxy vitamin D3 (25-OHD3; Hillman & Haddad, 1974; Ross, Care, Pickard, Peacock & Robinson, 1976; Weisman, Sapir, Harell & Edelstein, 1976). This paper describes the concentrations of 25-OHD3 in the plasma of pregnant and lactating ewes and their foetal and newborn lambs. Five ewes bearing single lambs were selected by radiography performed on day 100 of gestation in winter. The daily intakes of calcium, phosphate and magnesium for each animal were respectively, 11, 7 and 2 g. From day 26 pre partum until day 4 post partum, blood samples were collected through catheters implanted on day 115 of gestation in the left foetal and maternal carotid arteries (Mellor & Matheson, 1975). Plasma concentrations of 25-OHD3

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