INFLUENCE OF ANAESTHETICS, MATING, PREMATURE DELIVERY, THE TIME OF DAY OF BLOOD SAMPLING, AND SUCKLING ON PLASMA LEVELS OF LUTEINIZING HORMONE IN HAMSTERS

1975 ◽  
Vol 64 (3) ◽  
pp. 475-484 ◽  
Author(s):  
H. S. JOSHI ◽  
A. P. LABHSETWAR
Keyword(s):  
Luteinizing Hormone ◽  
Prostaglandin E2 ◽  
Plasma Levels ◽  
Chloral Hydrate ◽  
Post Partum ◽  
Time Of Day ◽  
Premature Delivery ◽  
Normal Delivery ◽  
Peripheral Plasma ◽  
Ether Anaesthesia

SUMMARY The influence of several factors on immunoreactive LH levels in peripheral plasma of female hamsters was investigated. The LH values for animals anaesthetized with either sodium pentobarbitone or chloral hydrate were significantly lower (P < 0-01) than those values obtained for hamsters sampled under ether anaesthesia. Mating on the night of pro-oestrus resulted in increased LH levels (P < 0-01) the following morning as compared with the levels in control females not caged with males. The LH levels were relatively low (13 ± 2 (s.e.m.) ng/ml) on the afternoon (16.00–18.00 h) of day 15 of pregnancy and also on the morning (09.00– 10.00 h) of day 16 before (7 ± 1 ng/ml) and after parturition (4 ± 0·2 ng/ml), but rose severalfold (561 ± 201 ng/ml) on the afternoon post partum. When premature delivery was induced on day 15 of pregnancy by administration of prostaglandin E2 the LH levels did not rise on the afternoon of this day (29± 11 ng/ml), but did so on the following afternoon (213± 115 ng/ml), at the same interval post coitum as in normal delivery. Marked increases in the concentration of LH in plasma were observed on the afternoon of each of days 0–6 post partum. The levels were comparable to those found on the afternoon of pro-oestrus in cyclic hamsters and could be blocked by administration of sodium phenobarbitone at 13.00 h. Similar afternoon surges of LH were not observed during dioestrus. In the morning, the LH levels were significantly higher (P < 0-001) in the non-suckled dams (95 ± 4 ng/ml) than those in mothers allowed to nurse their young (13± 4 ng/ml). In contrast, the levels in the afternoon were unaffected by the suckling stimulus (suckled, 495 ± 76 v. non-suckled, 744± 165 ng/ml; P > 0-05).

PLASMA LEVELS OF OESTROGEN AND PROGESTERONE IN PREGNANT AND LACTATING HAMSTERS

1974 ◽  
Vol 63 (1) ◽  
pp. 125-135 ◽  
Author(s):  
RICHARD BARANCZUK ◽  
G. S. GREENWALD
Keyword(s):  
Plasma Levels ◽  
Post Partum ◽  
Ovarian Tissue ◽  
Foetal Death ◽  
Antral Follicles ◽  
Peripheral Plasma ◽  
Progesterone Secretion ◽  
Baseline Levels ◽  
The One ◽  
Normal Gestation

SUMMARY Oestrone (OE1), oestradiol (OE2) and progesterone were measured by radioimmunoassay in the same samples of peripheral plasma from pregnant and lactating hamsters. The levels of progesterone during most of pregnancy did not exceed the values found during the first 2 days of the oestrous cycle. However, on day 14 of pregnancy (2 days before parturition) the level of progesterone abruptly increased to 29 ng/ml and fell rapidly thereafter. Hysterectomy on day 12 of pregnancy resulted in baseline levels of progesterone ( < 2 ng/ml) on day 13 and no peak in progesterone comparable to the one observed on day 14 of normal gestation. Injecting progesterone on day 14 or later prolonged gestation and caused maternal and foetal death. Oestradiol concentration showed peaks on days 7 (67·3 pg/ml), 11 (117·6 pg/ml) and 14 (81·8 pg/ml) of pregnancy and dropped precipitously between days 14 and 16 of pregnancy. The highest values obtained on day 11 correlated with the maximal proliferation of antral follicles. The abrupt decline of oestrogen concentration at parturition is different from the pattern found in the mouse and rat but is consistent with the lack of post-partum ovulation in the hamster. Injecting 50–150 μg oestradiol cyclopentylpropionate between days 12 and 16 did not interfere with parturition by the morning of day 16. Oestrone was detectable throughout pregnancy; the levels were lower than for OE2. In general, the oestrogen patterns were parallel. During lactation, progesterone secretion remained relatively constant at about 10–11 ng/ml, presumably synthesized by the hypertrophied interstitium which is the dominant ovarian tissue. In most instances OE1 and OE2 were not detectable during lactation, consistent with the absence of antral follicles.

PLASMA LEVELS OF ANDROSTENEDIONE, EPITESTOSTERONE, TESTOSTERONE AND OESTROGENS IN COWS AT PARTURITION

1981 ◽  
Vol 89 (2) ◽  
pp. 251-255 ◽  
Author(s):  
E. MÖSTL ◽  
K. MÖSTL ◽  
H. S. CHOI ◽  
H. K. DREIER ◽  
W. STÖCKL ◽  
...  
Keyword(s):  
Peripheral Blood ◽  
Plasma Levels ◽  
Post Partum ◽  
Peripheral Plasma ◽  
Androgen Levels

The concentration of total unconjugated oestrogens in the peripheral plasma of cows increased from 2·00±0·20 (s.e.m.) ng/ml 7 days before to 3·87±0·50 ng/ml 1 day before parturition and declined to values below 0·30 ng/ml on day 2 post partum. The concentrations of androstenedione, epitestosterone and testosterone remained approximately constant at 0·90±0·10,0·92±0·08 and 0·40±0·20 ng/ml respectively during the last week of pregnancy. After parturition the concentration of the three androgens declined rapidly. Similar to data obtained in goats we did not find a marked increase in androgen levels in the peripheral blood of cows before parturition.

THE INFLUENCE OF SURGERY, TIME OF DAY, BLOOD VOLUME REDUCTION AND ANAESTHETICS ON PLASMA PROLACTIN IN OVARIECTOMIZED RATS

1974 ◽  
Vol 62 (1) ◽  
pp. 75-83 ◽  
Author(s):  
D. M. LAWSON ◽  
R. R. GALA
Keyword(s):  
Blood Volume ◽  
Plasma Levels ◽  
Intraperitoneal Injection ◽  
Chloral Hydrate ◽  
Time Of Day ◽  
Volume Reduction ◽  
Ovariectomized Rats ◽  
Plasma Prolactin ◽  
Blood Samples ◽  
Subsequent Replacement

SUMMARY Plasma prolactin was measured by double antibody radioimmunoassay in ovariectomized rats bearing indwelling aortic catheters. Samples were obtained during recovery from ovariectomy and catheterization, at various times during the day, after blood volume reduction, and after administration of various anaesthetics. Prolactin levels were stabilized by day 3 after the operation but not by day 1. There was a significant (P < 0·01) increase in plasma prolactin during the afternoon in both ovariectomized rats and ovariectomized rats treated with 1 mg polyoestradiol phosphate. The magnitude of the response was more pronounced in the animals treated with oestrogen. Withdrawal of blood samples without subsequent replacement of fluid volume induced a significant (P < 0·05) decrease in plasma prolactin concentration after removal of only 1·2 ml blood within 20 min. No change was observed, however, when blood was replaced with saline. Ether and the intraperitoneal injection of sodium pentobarbitone produced prolonged increases in plasma prolactin whereas the intra-arterial administration of sodium pentobarbitone produced no change. Urethane and chloral hydrate caused only transient increases in plasma levels of prolactin regardless of the route of administration. Ketamine did not significantly alter plasma levels of prolactin.

PATTERNS OF CIRCULATING OESTRONE, OESTRADIOL-17β AND PROGESTERONE DURING PREGNANCY IN THE RHESUS MONKEY

1973 ◽  
Vol 74 (4) ◽  
pp. 743-755 ◽  
Author(s):  
William T. K. Bosu ◽  
Elof D. B. Johansson ◽  
Carl Gemzell
Keyword(s):  
Macaca Mulatta ◽  
Plasma Levels ◽  
Rhesus Monkeys ◽  
Post Partum ◽  
Follicular Phase ◽  
Gestational Period ◽  
The Third ◽  
Peripheral Plasma ◽  
Post Partum Period ◽  
Time Courses

ABSTRACT The maternal peripheral plasma levels of oestrone (E1)*, oestradiol-17β (E2) and progesterone (P) were determined by RIA during pregnancy in 8 rhesus monkeys (Macaca mulatta). Of special interest were the time courses and the inter-relationships of these steroids during the first month of pregnancy and during the pre- and post-parturient periods. A significant increase in the plasma levels of E1 and E2 occurred at the end of the fertile cycle and lasted for several days and again during the last week before parturition. The plasma levels of E1 and E2 fell dramatically after parturition and remained low during the immediate post-partum period. Two surges in the progesterone levels in plasma occurred at the end of the third week of the fertile cycle and between day 34 and 46 after the onset of menstruation. The progesterone levels in plasma during the remaining gestational period varied widely but a significant increase was found during the days before parturition. A decrease in the plasma levels of P was observed after parturition but the levels of P did not reach follicular phase levels during the post-partum period studied. The possibility of oestrogen secretion from follicles stimulated by chorionic gonadotrophins is discussed as well as the release of prostaglandins by oestrogen before parturition.

Influence of nutrition on pre-partum plasma levels of progesterone and total oestrogens and post-partum plasma levels of luteinizing hormone and follicle stimulating hormone in suckling cows

1983 ◽  
Vol 37 (1) ◽  
pp. 89-96 ◽  
Author(s):  
D. Gauthier ◽  
M. Terqui ◽  
P. Mauleon
Keyword(s):  
Luteinizing Hormone ◽  
Plasma Levels ◽  
Post Partum ◽  
Control Diet ◽  
Follicle Stimulating Hormone ◽  
Control Group ◽  
Luteinizing Hormone Concentration ◽  
The Mean ◽  
Daily Gain ◽  
Stimulating Hormone

ABSTRACTTwo groups of suckling Charolais cows were fed at different levels of nutrition from 70 days before the estimated date of calving until 45 days after calving, to study the effects of reduced dietary intake on pre-partum plasma levels of progesterone and total oestrogens (conjugated + unconjugated) and post-partum plasma levels of luteinizing hormone and follicle stimulating hormone. Eight control cows received a ration containing the Institut National de la Recherche Agronomique's recommendations for all nutrients, while 10 cows received a restricted diet which supplied approximately three-quarters of the recommended amounts for energy and nitrogen.The mean weight of the two groups of cows was similar at the beginning of the experiment but the restricted group had a significantly lower weight just before calving than the control group (678 v. 766 kg; P < 0·05).After calving, cows ont he low diet had a weight loss of 600 g/day, while those on the control diet gained 300 g/day. During the last 45 days of pregnancy underfeeding did not significantly affect oestrogen levels, but progesterone levels increased proportionally by 0·24 (P < 0·01).During the first 45 days of lactation underfeeding decreased the number of cows showing oestrus (0/10 v. 4/8) and significantly decreased both luteinizing hormone and follicle stimulating hormone levels at 5, 15 and 30 days post partum.Furthermore, the correlation between mean daily gain (0 to 45 days post partum) and luteinizing hormone concentration on day 30 was highly significant (r = 0·58; P < 0·01; no. = 19). These results suggest that the delay of the first post-partum ovulation in the underfed cow is due to low gonadotropin levels.

PERIPHERAL PLASMA LEVELS OF OESTROGENS, PROGESTERONE AND 17α-HYDROXYPROGESTERONE DURING GESTATION IN THE RHESUS MONKEY

1973 ◽  
Vol 74 (2) ◽  
pp. 348-360 ◽  
Author(s):  
William T. K. Bosu ◽  
Elof D. B. Johansson ◽  
Carl Gemzell
Keyword(s):  
Rhesus Monkey ◽  
Plasma Levels ◽  
Rhesus Monkeys ◽  
Post Partum ◽  
Plasma Concentrations ◽  
Normal Pregnancy ◽  
Follicular Phase ◽  
Gestation Period ◽  
Peripheral Plasma ◽  
Post Partum Period

ABSTRACT Peripheral plasma levels of oestrogens1), progesterone and 17α-hydroxyprogesterone were measured during normal pregnancy in seven rhesus monkeys. The plasma concentrations of oestrogens ranged between 200 and 1300 pg/ml throughout the gestation period. Increases in the levels of oestrogens in plasma occurred several days before parturition. The plasma concentrations of progesterone ranged between 0.5 and 22 ng/ml during pregnancy. The concentrations of oestrogens decreased dramatically after parturition and remained low during the post-partum period. The concentration of progesterone decreased after parturition, but did not reach follicular phase levels during the period observed. The plasma levels of 17α-hydroxyprogesterone were low throughout the gestation period and during the post-partum period.

Relation between intravascular electrolyte level and course of parturition in dairy cows

2013 ◽  
Vol 41 (05) ◽  
pp. 289-296 ◽  
Author(s):  
K. Seyrek-Intas ◽  
K. Failing ◽  
G. Yilmazbas Mecitoglu ◽  
H. Bostedt ◽  
D. Seyrek-Intas
Keyword(s):  
Dairy Cows ◽  
Inorganic Phosphate ◽  
Post Partum ◽  
Total Calcium ◽  
Normal Delivery ◽  
P Values ◽  
Normal Birth ◽  
Factors Influencing ◽  
Electrolyte Homeostasis ◽  
Convalescence Phase

Summary Objective: To determine the intravascular electrolyte status in dairy cows with respect to age and different courses of parturition to clarify etiological factors influencing peri- or intrapartal imbalances of electrolyte homeostasis. Material and methods: A total of 64 cows at birth were evaluated (primiparous n = 34, pluriparous n = 30). Thirty-three cows showed normal delivery, while 31 cows had a complicated birth. Blood samples were collected intra partum (i. p.) and 2, 4, 6, 8, 12, 16, 24 h post partum (p. p.) as well as [2, 3, 4, 5, 7, 10 days p. p. and levels of total calcium (Catotal), ionized calcium (Caion), inorganic phosphate (Pa), Mg, Na, K, Cl were determined. Results: The results revealed that electrolytes show great fluctuation during and immediately p. p. in relation to age. Already during parturition pluriparous cows had a lower Catotal and Pa concentration compared to primiparous animals. Cows with dystocia exhibited a more intensive and longer lasting decrease of Ca compared to cows with normal birth. In relation to age and severity of birth Pa concentration showed a differing but basically typical course for this electrolyte. Mg, Na, K and Cl concentrations were higher during and immediately after birth compared to p. p. values. Until day 10 p. p. these electrolyte concentrations declined more in older cows with dystocia compared to younger animals. However, the influence of dystocia on concentration of these electrolytes was milder in contrast to Ca and Pa. Conclusions: In summary, primarily older cows are predisposed to imbalances of electrolyte homeostasis intra partum and at the beginning of the lactation. These changes are potentiated in case of complications during parturition. Intravascular Catotal, Caion as well as Pa are most severely affected. Clinical relevance: These results may constitute the basis for a comprehensive metaphylaxis during the peripartal period, especially in cows after dystocia, to positively influence the early convalescence phase.

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.

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