Seasonal variation and circadian rhythmicity of the prolactin profile during the summer months in repeat-breeding Murrah buffalo heifers

2007 ◽  
Vol 19 (4) ◽  
pp. 569 ◽  
Author(s):  
Kajal S. Roy ◽  
Bukkaraya S. Prakash
Keyword(s):  
Prolactin Secretion ◽  
Circadian Rhythmicity ◽  
Oestrous Cycle ◽  
Gonadal Hormone ◽  
Plasma Prolactin ◽  
Murrah Buffalo ◽  
Progesterone Secretion ◽  
Endocrine Profile ◽  
Severe Heat Stress ◽  
The Mean

The present study was undertaken to determine a detailed endocrine profile for prolactin and progesterone during the oestrous cycle in repeat-breeding Murrah buffalo heifers during summer and winter. Hormone concentrations were quantified in blood plasma samples collected over the oestrous cycle in both winter and summer, as well as in samples collected during the summer months to observe circadian rhythmicity. The mean plasma prolactin concentration during the winter months ranged from 3.10 ± 0.48 to 9.17 ± 1.39 ng mL–1; during the summer months, plasma prolactin concentrations ranged from 248.50 ± 16.03 to 369.63 ± 25.13 ng mL–1. During the winter months, the mean plasma progesterone concentration ranged from 0.20 ± 0.00 to 3.04 ± 0.34 ng mL–1, which was significantly higher (P < 0.01) than the prolactin concentrations recorded in the summer months (range 0.20 ± 0.00 to 1.48 ± 0.13 ng mL–1). Plasma prolactin and progesterone concentrations were negatively correlated (r = –0.24) during the summer oestrous cycle, which indicates prolactin-induced suppression of progesterone secretion through poor luteal development. During the summer, a circadian rhythmicity was observed in buffaloes and the results indicate that high prolactin secretion contributes to poor fertility by lowering gonadal hormone (progesterone) secretion. It was concluded from the present study that prolactin and progesterone profiles during the summer and winter months are directly correlated with the reproductive performance of buffaloes. The finding also validates the hypothesis that hyperprolactinaemia may cause acyclicity/infertility in buffaloes during the summer months due to severe heat stress.

Seasonal patterns of luteal cyclicity in young red deer (Cervus elaphus) and sambar deer (Cervus unicolor)

1997 ◽  
Vol 9 (6) ◽  
pp. 587 ◽  
Author(s):  
G. W. Asher ◽  
P. D. Muir ◽  
G. Semiadi ◽  
K. T. O'Neill ◽  
I. C. Scott ◽  
...  
Keyword(s):  
Cervus Elaphus ◽  
Red Deer ◽  
Prolactin Secretion ◽  
Seasonal Patterns ◽  
Plasma Prolactin ◽  
Reproductive Seasonality ◽  
Plasma Progesterone ◽  
The Mean ◽  
Sambar Deer ◽  
Cervus Unicolor

Seasonal onset of pubertal ovulation and incidence of luteal cyclicity was assessed from plasma progesterone proles over 15 months for tame red deer (n = 7) and sambar deer (n = 7) hinds. Seasonal responses to photoperiod were determined from plasma prolactin proles. All red deer attained puberty at 17-18 months of age in May-June and expressed 3-6 luteal cycles of length 20·0 ± 10·4 days (mean ± s.e.m.) over 52-102 days. Six sambar deer attained puberty at 7-19 months of age, between August and December. Duration of luteal cyclicity was variable. While one animal remained continuously cyclic for 13 months, most entered anoestrus between November and February. The mean length of the luteal cycle was 17·2 ± 0·3 days. While red deer exhibited strongly seasonal patterns of prolactin secretion, sambar deer showed no such seasonal trends. The data collectively indicate that young sambar hinds at temperate latitudes exhibit loosely dened patterns of reproductive seasonality that are 4-6 months out of phase with those of red deer, although some individuals may be non-seasonal. Failure to express seasonal patterns of prolactin secretion indicates that sambar deer may not perceive photoperiodic cues to the same extent as do red deer.

scholarly journals Serotonin antagonist-induced lowering of prolactin secretion does not affect the pattern of pulsatile secretion of follicle-stimulating hormone and luteinizing hormone in the bitch

Reproduction ◽  
2004 ◽  
Vol 128 (2) ◽  
pp. 181-188 ◽  
Author(s):  
N J Beijerink ◽  
H S Kooistra ◽  
S J Dieleman ◽  
A C Okkens
Keyword(s):  
Dopamine Agonists ◽  
Area Under The Curve ◽  
Prolactin Secretion ◽  
Plasma Prolactin ◽  
Serotonin Antagonist ◽  
Basal Plasma ◽  
Ovarian Folliculogenesis ◽  
The Mean ◽  
Lh Secretion ◽  
Agonistic Effect

Dopamine agonists decrease plasma prolactin concentration and shorten the duration of anoestrus in the bitch. In order to determine whether this shortening results from decreased prolactin release or is due to another dopamine agonistic effect on the pulsatile release of FSH and LH, eight anoestrous beagle bitches were treated with a low dose of the serotonin antagonist metergoline (0.1 mg per kg body weight, twice daily) starting 100 days after ovulation. Six-hour plasma profiles of LH and FSH were obtained 7 days before, immediately before, 1 week after, and then at 2-week intervals after the start of the treatment with the serotonin antagonist until signs of pro-oestrus appeared. Plasma prolactin concentration was measured three times weekly from 75 to 142 days after ovulation and thereafter once weekly until the next ovulation, and was observed to decrease significantly after the start of treatment. The length of the interoestrous interval in the treated dogs was, however, not different from that in the preceding pretreatment cycle or from that in a group of untreated bitches. During the first weeks of treatment no changes were observed in the pulsatile plasma profiles of FSH and LH. Four weeks after the start of the treatment with the serotonin antagonist there was an increase in the mean basal plasma FSH concentration and the mean area under the curve for FSH, without a concurrent increase in LH secretion. The increase in FSH secretion continued until late anoestrus. In conclusion, the serotonin antagonist-induced lowering of plasma prolactin concentration was not associated with shortening of the interoestrous interval. The plasma profiles of LH and FSH were similar to those observed during physiological anoestrus, but different from those observed during anoestrus shortened by treatment with a dopamine agonist. Hence the prematurely induced oestrus observed during administration of dopamine agonists cannot be explained by a decreased plasma prolactin concentration but must be due to some other dopamine agonistic effect, probably increased FSH secretion. The observations in this study further strengthen the hypothesis that an increase in circulating FSH is essential for ovarian folliculogenesis and consequently the termination of anoestrus in the bitch.

EFFECT OF GONADOTROPHINS ON THE PRODUCTION OF STEROIDS BY SHEEP OVARIAN FOLLICLES CULTURED IN VITRO

1973 ◽  
Vol 58 (3) ◽  
pp. 599-611 ◽  
Author(s):  
R. M. MOOR ◽  
MARY F. HAY ◽  
J. E. A. McINTOSH ◽  
B. V. CALDWELL
Keyword(s):  
Ovarian Follicles ◽  
Oestrous Cycle ◽  
Culture Period ◽  
Daily Output ◽  
Progesterone Production ◽  
Progesterone Secretion ◽  
The Mean ◽  
Pregnant Mare Serum Gonadotrophin

SUMMARY The main objective of the study was to determine the rate at which Graafian follicles of sheep that had been treated with exogenous gonadotrophin acquire the ability to secrete oestrogen in vitro. Follicles were explanted from sheep 5 min to 24 h after injection of pregnant mare serum gonadotrophin (PMSG) and kept individually in culture for 7 days. The mean daily output of oestrogen by follicles from PMSG-treated sheep was higher than that secreted by follicles from untreated sheep. However, only a certain proportion of the follicles from each sheep secreted significant amounts of oestrogen in vitro; these follicles were called 'stimulated'. The proportion of stimulated follicles was 5% for control sheep, 20–30% for follicles explanted from sheep 5 min to 12 h after injection with PMSG, and 80% for follicles explanted from sheep that had been injected with PMSG 24 h previously. In the second part of the study, the pattern of oestrogen and progesterone secretion by stimulated follicles of different sizes explanted from PMSG-treated sheep at various stages of the oestrous cycle was determined. Up to the 14th day, oestrogen production in vitro by follicles over 4·5 mm in diameter reached a maximum 2 days after PMSG injection and decreased thereafter; progesterone production rose steadily as the oestrogen levels declined. In contrast, follicles of less than 4·5 mm diameter secreted considerable amounts of oestrogen for the first 5 days in culture, but produced only small quantities of progesterone. In follicles explanted on day 15, oestrogen secretion decreased steadily from the beginning of the culture period and was very low by the 4th day. Most follicles explanted at oestrus secreted only small amounts of oestrogen in vitro but secreted large amounts of progesterone.

Regulation in pregnant mink (Mustela vison) of plasma progesterone and prolactin concentrations and regulation of onset of the spring moult by daylight ratio and melatonin injections

1983 ◽  
Vol 61 (9) ◽  
pp. 1959-1963 ◽  
Author(s):  
L. Martinet ◽  
D. Allain ◽  
M. Meunier
Keyword(s):  
Prolactin Secretion ◽  
The Other ◽  
Short Photoperiod ◽  
Plasma Prolactin ◽  
Positive Relation ◽  
Vernal Equinox ◽  
Plasma Progesterone ◽  
Progesterone Secretion ◽  
The One ◽  
L 13

In pregnant or pseudopregnant mink maintained under natural daylight conditions and mated early in March, plasma prolactin and progesterone levels began to increase after the vernal equinox. The onset of spring moult was observed a few days later. When the females were transferred to a 15 h light (L): 9 h dark (D) photoperiod just after mating, prolactin and progesterone increase was advanced by several days; when the mink were transferred to an 11 h L: 13 h D schedule, these increases, as well as the onset of spring moult, were delayed or inhibited. A daily afternoon injection of melatonin mimicked the effects of short photoperiod. A positive relation was observed between plasma prolactin on the one hand and progesterone secretion or onset of moulting on the other. These results suggest that short photoperiod or melatonin effects might act by inhibiting prolactin secretion.

Pro-oestrous-specific role for polyamines in mediating the secretion of prolactin induced by thyrotrophin-releasing hormone in the rat

1993 ◽  
Vol 137 (1) ◽  
pp. 133-139 ◽  
Author(s):  
G. A. Wynne-Jones ◽  
A. M. Gurney
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Prolactin Secretion ◽  
Anterior Pituitary Gland ◽  
Oestrous Cycle ◽  
Male Rats ◽  
Pituitary Cells ◽  
Plasma Prolactin ◽  
Thyrotrophin Releasing Hormone ◽  
Releasing Hormone

ABSTRACT The activity of ornithine decarboxylase (ODC) in the rat anterior pituitary gland varies during the oestrous cycle, with a rise in activity seen at pro-oestrus. This enzyme, which is rate-limiting for the synthesis of the polyamines, can be specifically and irreversibly blocked by α-difluoromethylornithine (DFMO). A previous study showed that when this drug was administered to rats in vivo on the afternoon of pro-oestrus, it suppressed the normal surge in plasma prolactin levels that occurred later that day. The effect of DFMO was associated with reduced levels of putrescine in the anterior pituitary gland, suggesting that ODC activity in the lactotroph might be involved in the prolactin surge. We have examined the effects of DFMO on the secretion of prolactin from anterior pituitary cells, isolated either from male rats or from females at different stages of the oestrous cycle. The drug was found to reduce prolactin secretion stimulated by thyrotrophin-releasing hormone (TRH), but only in cells isolated from pro-oestrous animals and only for 2 days after cell isolation. Basal secretion was unaffected by DFMO. The results imply that ODC is important for TRH-stimulated prolactin secretion at pro-oestrus, and it is specific for pro-oestrus. The prolactin surge could therefore be influenced by this ODC-dependent effect of TRH. The pro-oestrous-specific response to TRH may be a consequence of the increased ODC activity seen at this time. Alternatively, the increased ODC activity could be a consequence of coupling to TRH receptors, which are known to increase in number at pro-oestrus. Journal of Endocrinology (1993) 137, 133–139

PROGESTERONE IN THE HUMAN PERIPHERAL BLOOD IN THE PREOVULATORY PERIOD OF THE MENSTRUAL CYCLE

1967 ◽  
Vol 55 (1) ◽  
pp. 91-96 ◽  
Author(s):  
Benno Runnebaum ◽  
Josef Zander
Keyword(s):  
Menstrual Cycle ◽  
Corpus Luteum ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Progesterone Concentration ◽  
Plasma Progesterone ◽  
Progesterone Secretion ◽  
Graafian Follicle ◽  
The Mean ◽  
Mean Concentration

ABSTRACT Progesterone was determined and identified in human peripheral blood during the preovulatory period of the menstrual cycle, by combined isotope derivative and recrystallization analysis. The mean concentration of progesterone in 1.095 ml of plasma obtained 9 days before ovulation was 0.084 μg/100 ml. However, the mean concentration of progesterone in 1.122 ml of plasma obtained 4 days before ovulation was 0.279 μg/100 ml. These data demonstrate a source of progesterone secretion other than the corpus luteum. The higher plasma-progesterone concentration 4 days before ovulation may indicate progesterone secretion of the ripening Graafian follicle of the ovary.

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.

Pineal denervation by cervical sympathetic ganglionectomy suppresses the role of photoperiod on pregnancy or pseudopregnancy, body weight and moulting periods in the mink (Mustela vison)

1985 ◽  
Vol 107 (1) ◽  
pp. 31-39 ◽  
Author(s):  
L. Martinet ◽  
D. Allain ◽  
Y. Chabi
Keyword(s):  
Body Weight ◽  
Environmental Factors ◽  
Prolactin Secretion ◽  
Corpora Lutea ◽  
Progesterone Secretion ◽  
Cervical Ganglion ◽  
Cervical Sympathetic ◽  
Implantation Period ◽  
Short Days

ABSTRACT In mink, termination of the delayed implantation period, following reactivation of the corpora lutea, and onset of the spring moult are associated with a rise in prolactin secretion triggered by increasing daylength, while decreasing daylength induces the autumn moult. To establish whether suppression of the function of the pineal rendered the mink unresponsive to daylength changes, the superior cervical ganglion was removed bilaterally 2–4 weeks before mating. Intact and operated females were then left outdoors or were put under a lighting regime of either 15 h light: 9 h darkness (15L: 9D) or 8L: 16D. In July, at the end of the spring moult, the 15L: 9D lighting regime was changed to one of 8L: 16D. Under artificial photoperiods ganglionectomy suppressed the stimulatory role of long days and the inhibitory role of short days on prolactin secretion, and consequently on progesterone secretion and spring moult. Neither was the autumn moult, induced early in intact females by the change to a short photoperiod, advanced in ganglionectomized females, showing that the latter were unresponsive to the artificial modification of the photoperiod. However, in animals kept outdoors, prolactin and progesterone secretion and spring moult were not changed by ganglionectomy. Increase in body weight and autumn moult were only slightly delayed by the operation suggesting that other environmental factors had replaced the synchronizing effect of the daylength changes. Alternatively the desynchronization between intact females responsive to photoperiodism and those rendered unresponsive may be too slow to be observed soon after ganglionectomy. J. Endocr. (1985) 107, 31–39

EFFECT OF LOW ZINC INTAKE DURING PREGNANCY ON PLASMA PROLACTIN, PROGESTERONE, PROSTAGLANDIN, CORTISOL AND PROTEIN CONCENTRATIONS OF EWES DURING THE PERIPARTURIENT PERIOD

1986 ◽  
Vol 66 (3) ◽  
pp. 643-651 ◽  
Author(s):  
J. A. FITZGERALD ◽  
G. A. EVERETT ◽  
J. APGAR
Keyword(s):  
Plasma Concentrations ◽  
Normal Pregnancy ◽  
Late Gestation ◽  
Plasma Prolactin ◽  
Plasma Parameters ◽  
Zinc Intake ◽  
Periparturient Period ◽  
Prostaglandin F ◽  
The Mean ◽  
Pregnant Ewe

The effect of low dietary Zn intake upon several plasma endocrine and metabolic profiles was examined during late gestation in the ewe. Thirty adult, primiparous Finncross ewes were fed a low Zn diet with (+Zn, n = 14) or without (0Zn, n = 16) supplemental Zn in the drinking water starting day 1 of pregnancy. Although the mean prepartum progesterone and prolactin concentrations were lower (P < 0.05 and P < 0.01, respectively) in 0Zn than in +Zn ewes, the peak prolactin concentrations in 0Zn ewes at lambing were similar to +Zn ewes. Both basal and thyrotropin-releasing-hormone (TRH)-induced prolactin release were less (P < 0.01) in 0Zn ewes 2 d postpartum. Plasma concentrations of 13, 14-dihydro-15-keto prostaglandin F2α (PGFM) of ewes sampled within 45 min post-lambing were lower (P < 0.05) in 0Zn ewes. There was no difference in cortisol concentrations within 45 min after lambing between 0Zn and + Zn ewes. Plasma protein concentrations in 0Zn ewes were higher (P < 0.01) than those in +Zn ewes during pregnancy. In summary, these data show that low Zn intake in the pregnant ewe affected several endocrine and metabolic plasma parameters associated with normal pregnancy and parturition. Key words: Zinc, parturition, dystocia, feed intake, ovine

The effect of ketamine hydrochloride anesthesia on basal and N-methyl-D,L-aspartate induced plasma prolactin secretion in the adult male rhesus monkey

Life Sciences ◽  
2001 ◽  
Vol 68 (9) ◽  
pp. 1083-1093 ◽  
Author(s):  
S.S.R. Rizvi ◽  
S. Altaf ◽  
A.A. Naseem ◽  
M. Asif ◽  
Z. Rasul ◽  
...  
Keyword(s):  
Rhesus Monkey ◽  
Adult Male ◽  
Prolactin Secretion ◽  
Plasma Prolactin ◽  
Ketamine Hydrochloride ◽  
Male Rhesus
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