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.

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.

Mullerian inhibiting substance production and testicular migration and descent in the pouch young of a marsupial

Development ◽  
1988 ◽  
Vol 104 (4) ◽  
pp. 549-556 ◽  
Author(s):  
J.M. Hutson ◽  
G. Shaw ◽  
W.S. O ◽  
R.V. Short ◽  
M.B. Renfree
Keyword(s):  
Tammar Wallaby ◽  
Testicular Descent ◽  
Future Studies ◽  
Macropus Eugenii ◽  
Müllerian Inhibiting Substance ◽  
Sequence Of Events ◽  
Testicular Differentiation ◽  
Testicular Migration ◽  
Australian Marsupial ◽  
Mullerian Inhibiting Substance

The ontogeny of Mullerian inhibiting substance (MIS) production by the developing testis of an Australian marsupial, the tammar wallaby (Macropus eugenii), was determined during pouch life using an organ-culture bioassay of mouse fetal urogenital ridge. This information was related to the morphological events during testicular migration and descent. MIS biological activity was found in testes (but not ovaries or liver) of pouch young from 2 to 85 days of age. MIS production had commenced by day 2, which is within a day of the first gross morphological signs of testicular differentiation. Mullerian duct regression occurred between 10 and 30 days, which partly coincided with testicular migration to the inguinal region and enlargement of the gubernacular bulb (15 to 30 days). These observations are consistent with the hypothesis that MIS may be involved in testicular transabdominal migration. The epididymis commenced development and growth only after the testis had descended through the inguinal ring. This provides no support for the suggestion that the epididymis is involved in testicular descent into the scrotum. The basic sequence of events in post-testicular sexual differentiation in the wallaby is sufficiently similar to that seen in eutherian mammals to make it an excellent experimental model for future studies of testicular differentiation, migration and descent.

Development of the lymphoid tissues of the tammar wallaby Macropus eugenii

1997 ◽  
Vol 9 (2) ◽  
pp. 243 ◽  
Author(s):  
K. Basden ◽  
D. W. Cooper ◽  
E. M. Deane
Keyword(s):  
Lymph Nodes ◽  
Immunoglobulin G ◽  
Lymphoid Tissue ◽  
Post Partum ◽  
Tammar Wallaby ◽  
Didelphis Virginiana ◽  
Lymphoid Tissues ◽  
Macropus Eugenii ◽  
Germinal Centres

A study has been made of the development of four lymphoid tissues from birth to maturity in the tammar wallaby Macropus eugenii —the cervical and thoracic thymus, lymph nodes and gut-associated lymphoid tissue (GALT). The development of these tissues in the tammar wallaby is similar to that in two other marsupials, the quokka Setonix brachyurus and the Virginian opossum Didelphis virginiana. Lymphocytes were first detected in the cervical thymus of the tammar at Day 2 post partum and in the thoracic thymus at Day 6. They were subsequently detected in lymph nodes at Day 4 and in the spleen by Day 12 but were not apparent in the GALT until around Day 90 post partum. By Day 21, the cervical thymus had developed distinct areas of cortex and medulla and Hassall’s corpuscles were apparent. The maturation of other tissues followed with Hassall’s corpuscles in the thoracic thymus by Day 30 and nodules and germinal centres in the lymph nodes by Day 90. Measurement of immunoglobulin G concentrations in the serum of young animals indicated a rise in titre around Day 90 post partum, correlating with the apparent maturation of the lymphoid tissues.

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.

Prostaglandin in the peripheral plasma of tammar wallabies during parturition

1986 ◽  
Vol 111 (1) ◽  
pp. 103-109 ◽  
Author(s):  
P. R. Lewis ◽  
T. P. Fletcher ◽  
M. B. Renfree
Keyword(s):  
Direct Measurement ◽  
Post Partum ◽  
Macropus Eugenii ◽  
Expected Time ◽  
Peripheral Plasma ◽  
Prostaglandin Metabolite ◽  
Prostaglandin F ◽  
Peripartum Period ◽  
Frequent Sampling ◽  
Breeding Seasons

ABSTRACT Tammar wallabies (Macropus eugenii) were observed for 7 days, 24 h/day, at the expected time of birth in two consecutive breeding seasons. Blood was collected from the lateral tail vein 1–2 days before birth, then at 10- to 20-min intervals in the peripartum period and less frequently to 30-h post partum. Plasma was assayed for the prostaglandin metabolite 13, 14-dihydro-15-oxo-prostaglandin F2α (PGFM), progesterone and LH. An assay for PGFM was validated which allows direct measurement in 100 μl unextracted plasma with a sensitivity of 0·14 nmol/l (50 pg/ml). There was a short-lived peak of PGFM immediately before or at birth (7·15 ± 2·52 nmol/l; 2536± 892 pg/ml) which declined to less than 0·28 nmol/l (100 pg/ml) within 2-h post partum. Progesterone concentrations declined about the time of birth, coincident with the peak of PGFM, and reached levels observed in lactationally quiescent animals by 16-h post partum, which was also the time of the LH peak. The transient prostaglandin pulse was detected only by frequent sampling and suggests that, as in other mammals, prostaglandin is important in parturition. J. Endocr. (1986) 111, 103–109

The tammar wallaby: a non-traditional animal model to study growth axis maturation

2019 ◽  
Vol 31 (7) ◽  
pp. 1276
Author(s):  
Jennifer A. Hetz ◽  
Brandon R. Menzies ◽  
Geoffrey Shaw ◽  
Marilyn B. Renfree
Keyword(s):  
Growth Hormone ◽  
Animal Model ◽  
Growth Factor ◽  
Animal Models ◽  
Growth Rates ◽  
Tammar Wallaby ◽  
Macropus Eugenii ◽  
Growth Axis ◽  
Functional Maturation ◽  
Peripartum Period

Maturation of the growth hormone (GH)/insulin-like growth factor 1 (IGF1) axis is a critical developmental event that becomes functional over the peripartum period in precocial eutherian mammals such as sheep. In mice and marsupials that give birth to altricial young, the GH/IGF1 axis matures well after birth, suggesting that functional maturation is associated with developmental stage, not parturition. Recent foster-forward studies in one marsupial, the tammar wallaby (Macropus eugenii), have corroborated this hypothesis. ‘Fostering’ tammar young not only markedly accelerates their development and growth rates, but also affects the timing of maturation of the growth axis compared with normal growing young, providing a novel non-traditional animal model for nutritional manipulation. This review discusses how nutrition affects the maturation of the growth axis in marsupials compared with traditional eutherian animal models.

scholarly journals 72 Endocrine and ovarian responses to combined estradiol benzoate-sulpiride in anestrous mares treated with kisspeptin

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 36-36
Author(s):  
Victoria N Bailey ◽  
Jennifer L Sones ◽  
Caroline M Camp ◽  
Erin L Oberhaus
Keyword(s):  
Repeated Measures ◽  
Estradiol Benzoate ◽  
Blood Sampling ◽  
Plasma Prolactin ◽  
Plasma Progesterone ◽  
Serial Blood ◽  
Osmotic Pumps ◽  
Pump Placement ◽  
Serial Blood Sampling ◽  
And Control

Abstract The objective of this study was to determine if incorporation of kisspeptin 10 (Kp10) into an estradiol benzoate (EB)-sulpiride treatment would result in greater endocrine responses, and a greater number of mares ovulating within 28 days of treatment compared to EB-sulpiride alone. Eighteen anestrous mares were blocked by horse type (light horse and pony crosses), body condition, and age, then randomly assigned to treatment or control. On day 0, all mares received 50 mg EB. On day 1, mini osmotic pumps containing saline (n = 9) or Kp10 (50 mg/hour; n = 9) were inserted subcutaneously in the neck and remained for 7 days. Serial blood sampling occurred for 24 hours after pump placement. On day 2, all mares received 3 g sulpiride. Serial blood sampling continued for 36 hours and daily for 28 days. Transrectal ultrasounds were performed regularly for detection of ovulation. Plasma was assayed for prolactin, luteinizing hormone (LH) and progesterone. Data were analyzed by ANOVA with repeated measures. Plasma prolactin increased (P < .001) in response to sulpiride in all mares and remained stimulated for 7 days. Prolactin responses tended to be greater (P = .09) in Kp10- treated mares compared to controls. No differences were detected in plasma LH during the first 24 hours after pump placement; however, LH increased in all mares beginning 5 days after sulpiride and were greater (P < .05) in Kp10-mares from day 7 to day 21. Eleven of 18 (61%) mares ovulated within 18 days of sulpiride treatment; however, no differences in ovulation dates were detected between Kp10 treated- and control- mares. No differences were detected in plasma progesterone during the first 5 days post ovulation. In conclusion, incorporation of Kp10 potentiated the prolactin and LH responses to EB-sulpiride, but did not further advance first ovulation in treated-mares.

scholarly journals Changes in the Milk Proteins during Lactation in the Tammar Wallaby, Macropus eugenii

1982 ◽  
Vol 35 (2) ◽  
pp. 145 ◽  
Author(s):  
Stuart W Green ◽  
Marilyn B Renfree
Keyword(s):  
Protein Concentration ◽  
Post Partum ◽  
Whey Proteins ◽  
Milk Proteins ◽  
Tammar Wallaby ◽  
Total Protein Concentration ◽  
Mean Values ◽  
Macropus Eugenii ◽  
Stage Of Lactation ◽  
Whole Milk

Samples of whey proteins from the milk of tammar wallabies, Macropus eugenii, were examined by acrylamide gel electrophoresis at all stages of lactation up to 280 days post partum. Whey albumin, ,B-globulin and y-globulin fractions had similar electrophoretic mobility to that of the equivalent serum protein fractions, but the proteins in the IX-globulin and pre-albumin regions differed markedly. The IX-globulins are presumed polymorphic because individuals at the same stage of lactation showed great variability in these electrophoretic regions: up to five polymorphic bands were recognized. Milk proteins changed qualitatively throughout lactation, and in particular the concentration of the pre-albumin and IX-globulin fractions increased from approximately day 180 to the end of lactation. Total protein concentration of both whole milk and whey approximately doubled in the second half of lactation compared to the first half, reaching maximum mean values of 114 � 47 and 96 � 50 g 1- 1 , respectively. Whole milk contained consistently more protein than whey, presumably due to the casein it contains.

Sperm transport, size of the seminal plug and the timing of ovulation after natural mating in the female tammar wallaby Macropus eugenii

2004 ◽  
Vol 16 (8) ◽  
pp. 811 ◽  
Author(s):  
Damien B. B. P. Paris ◽  
David A. Taggart ◽  
Monica C. J. Paris ◽  
Peter D. Temple-Smith ◽  
Marilyn B. Renfree
Keyword(s):  
Reproductive Tract ◽  
Post Partum ◽  
Tammar Wallaby ◽  
Sperm Storage ◽  
Sperm Transport ◽  
Macropus Eugenii ◽  
Large Numbers ◽  
Single Mating ◽  
Natural Mating

The distribution of spermatozoa and seminal plug in the reproductive tract and the timing of ovulation were examined at various times in a naturally mated monovular macropodid marsupial, namely the tammar wallaby (Macropus eugenii). After the first post partum (p.p.) mating, 28 females were isolated and their reproductive tracts dissected at 0.5, 6, 18, 36 and 40 h post coitum (p.c.). Each tract was ligated into 13 major anatomical sections and spermatozoa and eggs were recovered by flushing. Mating was possibly delayed by handling and occurred 21.7 ± 2.5 h p.p. in these animals. Copulation lasted 7.8 ± 0.7 min. Within 0.5 h after a single mating, the tract contained 25.8 ± 10.2 × 106 spermatozoa and 21.6 ± 8.8 g of seminal plug, 96% and 70% of which was lost within 6 h p.c. respectively. Spermatozoa reached the uterus, isthmus and ampulla of the oviduct on the side of the developing follicle within 0.5, 6 and 18 h p.c., respectively, and a uterine population of 26.1 ± 12.103 spermatozoa was maintained for over 40 h. Sperm numbers were reduced at the cervix (up to 57-fold) and uterotubule junction (eight-fold) and only one in approximately 7500 ejaculated spermatozoa (3.4 ± 0.9 × 103) reached the oviduct on the follicle side. Differential transport of spermatozoa was not observed. Although the numbers of spermatozoa were reduced in the parturient uterus, they were highly variable and were not significantly different to those in the non-parturient uterus. Ovulation and recovery of sperm-covered eggs from the isthmus occurred 36–41 h p.c. (49–72 h p.p.). In contrast with the polyovular dasyurid and didelphid marsupials, the tammar wallaby ejaculates large numbers of spermatozoa, but transport is relatively inefficient and sperm storage in the tract before ovulation is limited.

Sign in / Sign up

Export Citation Format

Share Document