PERIPHERAL PLASMA PROGESTERONE DURING PREGNANCY AND THE OESTROUS CYCLE IN THE TAMMAR WALLABY, MACROPUS EUGENII

1972 ◽  
Vol 55 (1) ◽  
pp. 63-71 ◽  
Author(s):  
MEREDITH LEMON
Keyword(s):  
Mammalian Species ◽  
Tammar Wallaby ◽  
Oestrous Cycle ◽  
Plasma Progesterone ◽  
Common Assumption ◽  
Macropus Eugenii ◽  
Peripheral Plasma ◽  
Competitive Protein Binding ◽  
The Common ◽  
Circulating Levels

SUMMARY Progesterone or progestin concentrations were measured in the peripheral plasma of the tammar wallaby (Macropus eugenii) during pregnancy and the oestrous cycle, using a competitive protein-binding method. In common with most other members of the marsupial family Macropodidae, the tammar has a gestation period slightly shorter than one oestrous cycle, and the occurrence of pregnancy does not affect the time of onset of the following oestrus. This study was an attempt to obtain direct evidence for the common assumption that most macropodid marsupials secrete the same amounts of ovarian hormones during pregnancy as they do during the oestrous cycle. The effect on progesterone levels of ovariectomy and removal of the corpus luteum was also studied to discover whether an extra-ovarian source of progesterone exists during pregnancy. Circulating levels of both total plasma progestins and progesterone are very low compared with other mammalian species—less than 1 ng/ml at all stages of the reproductive cycle. An increase in plasma progesterone concentration, apparently of ovarian origin, occurs before birth and/or oestrus, and this may possibly be associated with parturition. The plasma progestin concentration during pregnancy, and that of progesterone during the last 10 days of pregnancy, were significantly greater than during the oestrous cycle.

Oestrous cycle of the common wombat, Vombatus ursinus, in Victoria, Australia

2004 ◽  
Vol 16 (3) ◽  
pp. 339 ◽  
Author(s):  
M. West ◽  
D. Galloway ◽  
J. Shaw ◽  
A. Trouson ◽  
M. C. J. Paris
Keyword(s):  
Epithelial Cells ◽  
Average Length ◽  
Follicular Phase ◽  
Oestrous Cycle ◽  
Vaginal Smears ◽  
Plasma Progesterone ◽  
In Captivity ◽  
Common Wombat ◽  
Vaginal Cytology ◽  
The Common

Wild-caught female common wombats from Victoria, Australia, were studied in captivity to investigate the oestrous cycle by assessing vaginal cytology and peripheral plasma progesterone concentrations. Eight wombats, five adults (21–29 kg) and three subadults (19–23 kg), which were held for between 2 weeks and 11 months did not cycle in captivity. Their progesterone concentrations were consistently low (≤6.9 nmol L–1) and vaginal smears contained predominantly superficial epithelial cells. Three wombats (21–27 kg), held in captivity for >1 year, regularly cycled (when bodyweights exceeded 23.5 kg). Information gathered from four consecutive cycles in each of these three wombats revealed a follicular phase with low progesterone concentrations (≤6.9 nmol L–1) and vaginal smears with a high percentage of superficial epithelial cells alternating with periods of high progesterone concentrations (range 41.6–123.8 nmol L–1) and smears in which parabasal–intermediate epithelial cells predominated. The average length of the monitored oestrous cycles was 47.2 days (35–60 days). The follicular phase lasted ~19 days and the luteal phase lasted ~28 days. In conclusion, wombats can cycle regularly in captivity even under conditions of intensive monitoring.

Effects of bromocriptine at parturition in the tammar wallaby, Macropus eugenii

1990 ◽  
Vol 2 (1) ◽  
pp. 79 ◽  
Author(s):  
TP Fletcher ◽  
G Shaw ◽  
MB Renfree
Keyword(s):  
Post Partum ◽  
Tammar Wallaby ◽  
Plasma Prolactin ◽  
Plasma Progesterone ◽  
Macropus Eugenii ◽  
Sequence Of Events ◽  
Prostaglandin Release ◽  
Peripartum Period ◽  
And Control ◽  
Subsequent Onset

Female tammar wallabies were treated with the dopamine agonist bromocriptine at the end of pregnancy to suppress the peripartum pulse of plasma prolactin. The animals were subsequently observed, and a series of blood samples taken to define the hormonal profiles before and immediately after parturition. Birth was observed in 4/5 control animals and occurred in 8/9 bromocriptine-treated animals. The peripartum peak in plasma PGFM concentrations was not affected by bromocriptine although the pulse of prolactin normally seen at parturition was completely abolished. The timing of luteolysis was apparently unaffected, as plasma progesterone concentrations fell similarly in both treated and control animals immediately after parturition. However, all of the neonates of the bromocriptine-treated animals died within 24 h, possibly because of a failure to establish lactation. Subsequent onset of post-partum oestrus was delayed or absent both in control and in bromocriptine-treated animals, suggesting that the frequent blood sampling and disturbances in the peripartum period interfered with these endocrine processes. It is concluded that both prolactin and prostaglandin can induce luteolysis in the pregnant wallaby, but that the normal sequence of events results from a signal of fetal origin inducing a prostaglandin release from the uterus, which in turn releases a pulse of prolactin that induces a progesterone decline.

Hormonal changes at oestrus, parturition and post-partum oestrus in the tammar wallaby (Macropus eugenii)

1983 ◽  
Vol 96 (1) ◽  
pp. 155-161 ◽  
Author(s):  
C. H. Tyndale-Biscoe ◽  
L. A. Hinds ◽  
C. A. Horn ◽  
G. Jenkin
Keyword(s):  
Post Partum ◽  
Tammar Wallaby ◽  
Oestrous Cycle ◽  
High Peak ◽  
Rapid Decline ◽  
Hormonal Changes ◽  
Progesterone Concentration ◽  
Macropus Eugenii ◽  
Slow Decline ◽  
Prostaglandin F

Concentrations of progesterone, prolactin, LH and 13,14 dihydro-15-keto-prostaglandin F2α (PGFM) were measured in plasma of eight tammar wallabies at 8-hourly intervals during the end of pregnancy and post-partum oestrus initiated by removing the pouch young, and during the end of the oestrous cycle, similarly initiated. In the non-pregnant cycle oestrus occurred 29·7 ± 0·7 (mean ±s.e.m.) days after initiation of the cycle, was preceded by a slow decline in progesterone concentration from 1·6 nmol/l to less than 0·64nmol/l and was followed by a preovulatory peak of LH 5·3± 3·9 h later. In the pregnant cycle birth occurred 26·1±0·2 days after removing the pouch young and was followed 8·0 ± 2·1 h later by oestrus and 16·0± 2·5 h by an LH peak. The latter events thus occurred 3·2 days earlier in the pregnant than in the non-pregnant cycle. Parturition coincided with a very rapid decline in progesterone and a transient high peak of prolactin. In two females sampled less than 25 min after parturition there was a transient peak of PGFM but in all others the concentrations of PGFM remained basal throughout. It is suggested that the fetus and/or placenta is involved in both the premature decline in progesterone and the initiation of parturition and that onset of oestrus and ovulation, being a consequence of a decline in progesterone, are therefore also determined by the fetus.

scholarly journals Selected Factors that Affect the Measurement of Plasma Progesterone Concentrations in Pregnant Ewes

1974 ◽  
Vol 27 (6) ◽  
pp. 659 ◽  
Author(s):  
AR Gleeson ◽  
GD Thorburn
Keyword(s):  
Protein Binding ◽  
Diurnal Variation ◽  
Significant Positive Correlation ◽  
Plasma Samples ◽  
Elevated Plasma ◽  
Progesterone Concentration ◽  
Plasma Progesterone ◽  
Blood Samples ◽  
Peripheral Plasma ◽  
Competitive Protein Binding

A competitive protein-binding technique was used to measure progesterone concentrations in the peripheral plasma of pregnant ewes. Neither haemolysis of blood nor thawing of plasma samples affected plasma progesterone concentration. Blood samples should be chilled immediately upon collection but subsequent to centrifugation immediate chilling of the plasma samples is not critical. No consistent diurnal variation in progesterone concentrations was evident but there was large apparently random day-to-day variation in progesterone concentrations for any ewe. Although a significant positive correlation was found between endogenous progesterone and corticosteroid concentrations, the present study failed to correlate experimentally elevated plasma corticosteroid concentrations with progesterone concentrations. Progesterone concentrations varied greatly between ewes at the same stage of pregnancy.

PERIPHERAL PLASMA PROGESTERONE CONCENTRATIONS IN SHEEP DURING THE OESTROUS CYCLE

1973 ◽  
Vol 58 (2) ◽  
pp. 219-225 ◽  
Author(s):  
K. P. McNATTY ◽  
K. J. A. REVFEIM ◽  
A. YOUNG
Keyword(s):  
Luteal Phase ◽  
Oestrous Cycle ◽  
Diurnal Changes ◽  
Progesterone Concentration ◽  
Once Daily ◽  
Plasma Progesterone ◽  
Blood Samples ◽  
Peripheral Plasma ◽  
The Hours

SUMMARY Progesterone concentrations in peripheral plasma were measured once daily during one oestrous cycle in each of eight sheep. In addition, on days 4–5, 8–9, 12–13 and 15–16 of the oestrous cycle, blood samples were collected at 30-min intervals throughout each 24-h period. A total of three ewes was sampled in each 24-h period and the same three animals were not bled again for at least 1 week. Plasma progesterone concentrations in all the ewes fluctuated considerably throughout each 24-h period. The within-sheep within-day variations observed in peripheral progesterone concentrations were compared with the between-sheep within-day variations and the within-sheep between-day variations previously reported. It is concluded that these previously reported variations in peripheral plasma progesterone concentration could be attributed to within-day variations in each animal. On days 8–9 and 12–13 of the oestrous cycle there were significantly higher concentrations of progesterone in plasma during the hours of daylight than during the hours of darkness. In contrast, progesterone concentrations on days 4–5 and 15–16 were not found to be significantly different between the hours of daylight and darkness. These results suggest that diurnal changes in peripheral plasma progesterone concentration occur during the luteal phase of the ovine oestrous cycle.

PROGESTERONE CONCENTRATION IN THE PERIPHERAL PLASMA OF PREGNANT GOATS

1972 ◽  
Vol 53 (3) ◽  
pp. 447-452 ◽  
Author(s):  
G. IRVING ◽  
D. E. JONES ◽  
A. KNIFTON
Keyword(s):  
Cord Blood ◽  
Venous Blood ◽  
Progesterone Concentration ◽  
Plasma Progesterone ◽  
Peripheral Plasma ◽  
Significant Difference ◽  
Competitive Protein Binding ◽  
The Mean ◽  
Serial Samples ◽  
Twin Pregnancies

SUMMARY Plasma progesterone concentration was measured by a competitive protein-binding method in serial samples of jugular venous blood from 21 pregnant goats, 11 with twin and 10 with single foetuses. Progesterone levels in twin pregnancies were significantly greater than in singletons. The mean progesterone concentration (ng/ml plasma) in the twin pregnancies was greatest during the 3rd month of gestation (10·7 ± 0·4 (s.e.m.)) and in the singletons during the 4th month (7·8 ± 0·2 (s.e.m.)). There was a significant decrease in mean progesterone concentration in the last month of pregnancy due to a steady decline in the last 7 days before parturition. The mean progesterone concentrations at parturition in five twin and eight single pregnancies were 2·2 ± 0·4 and 1·5 ± 0·2 (s.e.m.) ng/ml plasma respectively; there was no significant difference between these values. In cord blood from nine kids immediately after delivery the progesterone concentration was 0·9 ± 0·1 ng/ml.

Prostaglandin alone does not cause luteolysis in the non-pregnant tammar wallaby, Macropus eugenii

1991 ◽  
Vol 3 (1) ◽  
pp. 17 ◽  
Author(s):  
LA Hinds
Keyword(s):  
Sampling Period ◽  
Tammar Wallaby ◽  
Plasma Prolactin ◽  
Plasma Progesterone ◽  
Macropus Eugenii ◽  
Prostaglandin F2 Alpha ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

At parturition in the tammar wallaby, Macropus eugenii, the process of luteolysis involves both prostaglandin and prolactin. Prolactin alone is luteolytic, but it has been unclear whether prostaglandin F2 alpha (PGF2 alpha) is also directly luteolytic. To examine this, three groups non-pregnant animals were studied on Day 26 after removal of pouch young (the day equivalent to parturition). Group 1 (controls) received saline injections on Days 25 and 26, Group 2 received saline on Day 25 and PGF2 alpha on Day 26, and Group 3 was pre-treated with bromocriptine (Parlodel LA, Sandoz) on Day 25 and received PGF2 alpha on Day 26. For 12 h after treatment on Day 26, plasma progesterone and prolactin concentrations were determined and behaviour was recorded. Plasma progesterone concentrations remained elevated and plasma prolactin was basal throughout the sampling period in the control animals (Group 1). After treatment with PGF2 alpha (Group 2), plasma prolactin was elevated within 15 min and plasma progesterone decreased significantly (P less than 0.001) from 600 pg mL-1 (1.91 nmol L-1) to less than 200 pg mL-1 (0.64 nmol L-1) by 8 h. However, luteolysis did not occur in females pre-treated with bromocriptine on Day 25 and injected with PGF2 alpha on Day 26 (Group 3), and prolactin concentrations remained basal. All females treated with PGF2 alpha showed parturient behavior. The results clearly show that PGF2 alpha is not directly luteolytic on Day 26 of the non-pregnant cycle, but they confirm that PGF2 alpha induces the release of prolactin, which is directly luteolytic.

Sign in / Sign up

Export Citation Format

Share Document