Concentrations of luteinizing hormone and progesterone in plasma during sexual development of the Khaki Campbell duck

1982 ◽  
Vol 93 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Susan C. Wilson ◽  
T. R. Morris
Keyword(s):  
Plasma Concentration ◽  
Luteinizing Hormone ◽  
Negative Correlation ◽  
Sexual Development ◽  
Plasma Concentrations ◽  
Winter Solstice ◽  
Pronounced Increase ◽  
Threefold Increase ◽  
Lh Release

Concentrations of LH and progesterone were measured in the plasma of ducks which were, from 3 weeks of age, raised on either a constant photoperiod of 16 h light: 8 h darkness or a lighting schedule which simulated natural changes in daylength. In ducks raised on a constant photoperiod of 16 h light: 8 h darkness the plasma concentration of LH increased steeply between 7 and 3·5 weeks before the onset of lay. Concentrations of LH then declined, gradually at first, but then rapidly during the 7 days before the first oviposition in association with a pronounced increase in the plasma concentration of progesterone. During the 18 days before the first egg was laid there was a significant (P < 0·01) negative correlation between the plasma concentrations of LH and progesterone. The patterns of LH release during sexual development of ducks raised on a schedule which simulated natural changes in daylength were variable but could be categorized according to the daylength at which each duck came into lay. In ducks coming into lay soon after the winter solstice when daylength was short (8·0–8·5 h light/day) there was a pronounced 15-fold prepubertal increase in the plasma concentration of LH although in some ducks high LH levels were not maintained until 3–4 weeks before the first oviposition and were not always followed by a rise in the plasma concentration of progesterone. In contrast, in ducks coming into lay when daylength had increased to 11·0–11·5 h light/day there were only minor fluctuations in the plasma concentration of LH until a small two- to threefold increase in LH was observed during the 2 weeks before the first oviposition.

Evidence of a photoinducible phase for the release of luteinizing hormone in the domestic hen

1982 ◽  
Vol 94 (3) ◽  
pp. 397-406 ◽  
Author(s):  
Susan C. Wilson
Keyword(s):  
Plasma Concentration ◽  
Luteinizing Hormone ◽  
Control Group ◽  
Abrupt Increase ◽  
Threefold Increase ◽  
Main Period ◽  
Lh Release ◽  
Lh Releasing Hormone ◽  
Lh Secretion ◽  
Domestic Hen

Hens raised on a schedule of 8 h light: 16 h darkness (8L : 16D) were exposed to changes in photoperiod at 17 or 18 weeks of age. These involved exposure to either an abrupt increase in photoperiod to 16 h per day or to skeleton photoperiods comprising a main period of 7·75 or 4 h light together with a pulse of 15 min or 4 h light provided at different times during the period of darkness. An increase in photoperiod to 16 h per day stimulated a two- to threefold increase in the plasma concentration of LH within 1–3 days. Interruption of a 7·75L : 16D schedule by 15 min light between 13·75 and 19·75 h after the beginning of the main photoperiod stimulated LH secretion in the immature and adult hen and a higher rate of lay than that of the 8L : 16D control group. There was a significant (P < 0·01) correlation between the concentration of LH in the plasma and the rate of lay. The photostimulated rise in the plasma concentration of LH in the immature hen was not associated with any increase in the responsiveness of the pituitary gland to LH releasing hormone. Of the treatments in which a 15-min pulse of light was provided, the schedules of 7·75L : 10D : 0·25L : 6D and 7·75L : 12D : 0·25L : 4D, which were most effective in stimulating LH release, appeared to be interpreted as 0·25L : 6D : 7·75L : 10D and 0·25L : 4D : 7·75L : 12D respectively. In hens given a 7·75-h main photoperiod, in which phase-reversal did not occur, 15 min light was most stimulatory when given 14–16 h after the begining of the main photoperiod, although not to the same extent as an increase in photoperiod to 16 h per day. In hens for which an 8-h complete photoperiod was changed to a 4-h main photoperiod, together with a further 4-h pulse of light provided at different times during the period of darkness, the period of maximum sensitivity to light occurred 11 h after the onset of the main photoperiod and at this time light stimulated LH release to the same extent as an increase in complete photoperiod from 8 to 16 h per day. Results of this study suggest that the period of maximum photosensitivity shifts its phase after a change in the form of photoperiod and is primarily entrained to dusk.

Maturational changes in the LH response of domestic fowl to synthetic chicken LHRH-I and -II

1989 ◽  
Vol 123 (2) ◽  
pp. 311-318 ◽  
Author(s):  
S. C. Wilson ◽  
F. J. Cunningham ◽  
R. A. Chairil ◽  
R. T. Gladwell
Keyword(s):  
Plasma Concentration ◽  
Sexual Development ◽  
Plasma Concentrations ◽  
Egg Laying ◽  
Prolonged Action ◽  
Initial Rise ◽  
Lh Release ◽  
Higher Doses ◽  
Type Response ◽  
Sustained Increase

ABSTRACT Treatment of chickens at different stages of sexual development with a single i.v. injection of synthetic chicken LHRH (cLHRH)-I or -II stimulated a rise in the plasma concentration of LH within 1 min. The activity of cLHRH-II was 1·3- to 2·7-fold greater than that of cLHRH-I in sexually immature cockerels and hens as determined by the changes in the plasma concentration of LH during the 5 or 10 min after injection. This could be attributed to both a greater effectiveness of cLHRH-II to stimulate LH release and to a more prolonged action. Thus, LH concentrations in plasma were maximal within 1–2 min of injection of all doses of cLHRH-I but within 2–5 min of injection at the higher doses of cLHRH-II. The responsiveness of the pituitary gland to cLHRH-I and -II was substantially greater in the sexually immature cockerel than in the hen and diminished during sexual development of the hen. Coincident with the onset of egg laying, the characteristics of the LH response to cLHRH-II changed to consist of an initial rise during the first 2 min, followed by a more sustained increase with LH concentrations still rising 10 min after injection. In contrast, after injection with cLHRH-I, plasma concentrations of LH rose to a peak at 2 min and thereafter declined gradually. Treatment of the sexually immature hen with oestradiol, progesterone or a combination of both steroids did not enable the expression of a laying hen-type response to the injection of cLHRH-II. It would appear, therefore, that unidentified events associated with the final stages of sexual maturation bring about changes in the mechanism of action of cLHRH-II which differ from those of cLHRH-I. Journal of Endocrinology (1989) 123, 311–318

Developmental changes in the diurnal rhythm of secretion of corticosterone and LH in the domestic hen

1984 ◽  
Vol 101 (3) ◽  
pp. 299-304 ◽  
Author(s):  
S. C. Wilson ◽  
R. C. Jennings ◽  
F. J. Cunningham
Keyword(s):  
Plasma Concentration ◽  
Phase Angle ◽  
Diurnal Rhythm ◽  
Sexual Development ◽  
Plasma Concentrations ◽  
Transient Increase ◽  
Developmental Changes ◽  
Diurnal Changes ◽  
Pronounced Increase ◽  
Domestic Hen

ABSTRACT When diurnal changes in the plasma concentrations of corticosterone and LH were compared at various times during sexual development a diurnal rhythm in the secretion of corticosterone was most pronounced at 4·5 weeks of age in hens maintained on a schedule of 8 h light: 16 h darkness (8L: 16D) and at 8·5 weeks of age in hens maintained on 16L: 8D. At these ages the phase-angle of the rhythm in relation to the onset of darkness was 3 h earlier than had been observed in previous studies of the adult hen. The characteristics of the corticosterone rhythm changed during sexual development and diurnal changes were no longer evident in hens at 17 weeks of age at a time when prepubertal plasma concentrations of LH were maximal. However, there was a tendency for plasma concentrations of corticosterone to fluctuate diurnally in hens studied at less than 10 days before the onset of lay although not to the same extent as has previously been observed in the adult hen. This period of development was associated with a pronounced increase in the plasma concentration of progesterone. An increase in the plasma concentration of LH at the onset of darkness was observed at all ages in hens maintained on either photoschedule. In hens of 4·5–15 weeks of age maintained on 16L:8D or 8L:16D this increase in the plasma concentration of LH was sustained during the first 5 or 8–11 h of darkness respectively but at 17 weeks of age only a transient increase in LH was seen at the onset of darkness. Plasma concentrations of LH in samples of plasma taken at intervals of between 3 days and 2 weeks throughout sexual development were, until 18–19 weeks, consistently higher in hens maintained on a photoschedule of 16L:8D than on 8L: 16D. J. Endocr. (1984) 101, 299–304

PLASMA CONCENTRATIONS OF LUTEINIZING HORMONE, TESTOSTERONE AND ANDROSTENEDIONE IN CASTRATED AND ADRENALECTOMIZED BULL CALVES

1978 ◽  
Vol 79 (1) ◽  
pp. 137-138 ◽  
Author(s):  
J. J. BASS ◽  
A. J. PETERSON ◽  
E. PAYNE
Keyword(s):  
New Zealand ◽  
Plasma Concentration ◽  
Luteinizing Hormone ◽  
Agricultural Research ◽  
Plasma Concentrations ◽  
Young Male ◽  
Research Centre ◽  
Similar Magnitude ◽  
Research Division ◽  
Bull Calves

Ministry of Agriculture and Fisheries, Research Division, Ruakura Agricultural Research Centre, Hamilton, New Zealand (Received 17 April 1978) An increase in the plasma concentration of luteinizing hormone (LH) occurs in response to castration in bull calves aged 1–4 months; this response is of similar magnitude to that seen in cattle castrated as adults (Odell, Hescox & Kiddy, 1970). In bull calves castrated at birth, however, there is no increase in the plasma concentration of LH until after 28 days of age (Bass, Peterson, Payne & Jarnet, 1977). In other species a range of responses to castration has been reported. Gonadectomy of male guinea-pigs 0–35 days after birth produces an increase in the plasma concentration of LH similar to that observed in guineapigs castrated as adults (Donovan, ter Haar, Lockhart, MacKinnon, Mattock & Peddie, 1975). In contrast, the castration of young male macaques does not cause an immediate increase in the

VARIATIONS IN STORED AND PLASMA CONCENTRATIONS OF ANDROGENS AND LUTEINIZING HORMONE DURING SEXUAL DEVELOPMENT IN THE COCKEREL

1977 ◽  
Vol 74 (3) ◽  
pp. 467-476 ◽  
Author(s):  
P. J. SHARP ◽  
J. CULBERT ◽  
J. W. WELLS
Keyword(s):  
Luteinizing Hormone ◽  
Pituitary Gland ◽  
Sexual Development ◽  
Rapid Growth ◽  
Plasma Concentrations ◽  
Body Growth ◽  
Initial Increase ◽  
Temporary Reduction ◽  
Testicular Growth ◽  
Rate Of Growth

SUMMARY The concentrations of luteinizing hormone (LH) and testosterone in the plasma and the stored levels of LH, testosterone and androstenedione were measured in cockerels aged 8–29 weeks. The onset of puberty occurred between 16 and 24 weeks of age, when the testes entered a phase of rapid growth and spermatogenesis was completed. The following sequence of endocrine events was found to be associated with the onset of puberty: a fall in the amount of androstenedione in the testes before any evidence of increased testicular growth; an increase in the total amount of LH in the pituitary gland as the testes started to enlarge; an increase in the total amount of testosterone in the testes and in the concentration of LH in the plasma; an increase in the concentration of testosterone in the plasma. An increase in the rate of growth of the comb and testes preceded a detectable increase in the levels of LH and testosterone in the plasma. The increase in the amount of testosterone in the plasma which occurred after the initial increase in the concentration of LH was associated with the final stages of spermatogenesis, a decrease in the rate of body growth and a temporary reduction in the amount of LH secreted.

An investigation of diurnal and cyclic changes in the secretion of luteinizing hormone in the domestic hen

1983 ◽  
Vol 98 (1) ◽  
pp. 137-145 ◽  
Author(s):  
S. C. Wilson ◽  
R. C. Jennings ◽  
F. J. Cunningham
Keyword(s):  
Luteinizing Hormone ◽  
Diurnal Rhythm ◽  
Laying Hen ◽  
Ovulatory Cycle ◽  
Pronounced Increase ◽  
Threefold Increase ◽  
Steep Decline ◽  
Cyclic Changes ◽  
Lh Secretion ◽  
Domestic Hen

The characteristics of the diurnal rhythm in the concentration of LH in plasma of the domestic hen varied according to age and duration of photoperiod. A pronounced increase in LH was observed at the onset of darkness in immature hens whether maintained on schedules of 16 h light:8 h darkness (16L:8D) or 8L:16D. During weeks 4·5–15 or −17·5 raised concentrations of LH were maintained until 6 and 12 h after the onset of darkness in hens held on 16L:8D and 8L:16D respectively. By 19 weeks of age the diurnal rhythm of LH secretion had changed to resemble more closely that observed in the laying hen. An increase in the concentration of LH in plasma at the onset of darkness was of comparatively short duration and gave way, within 2–3 h, to a steep decline before a further slight increase in LH, which tended to occur at 11–14 h after the onset of darkness. Superimposed on this diurnal rhythm of LH secretion in the laying hen were a one- to threefold increase in the concentration of LH during 8–4 h before ovulation and a much less pronounced increase in LH during 0–8 h after ovulation. The pattern of changes in the concentration of LH in plasma during the ovulatory cycle was not modified by the repeated withdrawal of blood at intervals of 2 h.

EFFECT OF PHOTOPERIOD ON THE CONCENTRATIONS OF CORTICOSTERONE AND LUTEINIZING HORMONE IN THE PLASMA OF THE DOMESTIC HEN

1981 ◽  
Vol 91 (1) ◽  
pp. 135-143 ◽  
Author(s):  
SUSAN C. WILSON ◽  
F. J. CUNNINGHAM
Keyword(s):  
Plasma Concentration ◽  
Luteinizing Hormone ◽  
Continuous Light ◽  
Significant Rise ◽  
Maximal Concentration ◽  
Pronounced Increase ◽  
Circadian Periodicity ◽  
Free Running ◽  
Domestic Hen

Ovipositions in hens maintained under schedules of 16 h light: 8 h darkness (16L : 8D) or 8L : 16D were restricted to a 12 h period of the day while in hens maintained on continuous light, ovipositions occurred at times throughout the whole of the 24 h day. In hens maintained in continuous light a significant rise in the plasma concentration of corticosterone was observed 11–9 h before ovulation/oviposition. In hens in 16L : 8D there was an increase in the concentration of corticosterone in the plasma during the first 1·5 h of darkness which, under that schedule, coincides with the onset of the 'open period' for the occurrence of the preovulatory release of LH. In hens ovulating the first egg of a sequence the rise in the secretion of corticosterone was only transient and levels fell as preovulatory concentrations of LH rose to a peak. However, in hens undergoing an ovulation late in a sequence or in those not expected to ovulate, the concentration of corticosterone in the plasma continued to rise to attain a maximal concentration 8 h later. In hens maintained in 8L : 16D there was a tendency for the concentration of corticosterone in the plasma to increase at the beginning of the open period, 4 h after the onset of darkness, though this rise was much smaller than that observed at the beginning of the open period of hens on 16L : 8D. A further, more pronounced, increase in the concentration of corticosterone was observed between 11 and 15 h after the onset of darkness. It is suggested that the rise in the concentration of corticosterone at 11–9 h before ovulation in hens in continuous light reflects the beginning of an open period with a free-running circadian periodicity of 26–27 h.

Diurnal changes in the plasma concentrations of corticosterone, luteinizing hormone and progesterone during sexual development and the ovulatory cycle of Khaki Campbell ducks

1982 ◽  
Vol 93 (2) ◽  
pp. 267-277 ◽  
Author(s):  
Susan C. Wilson ◽  
F. J. Cunningham ◽  
T. R. Morris
Keyword(s):  
Plasma Concentration ◽  
Sexual Development ◽  
Temporal Relationship ◽  
Plasma Concentrations ◽  
Egg Laying ◽  
Diurnal Changes ◽  
Ovulatory Cycle ◽  
Night Time ◽  
Khaki Campbell Ducks ◽  
Relationship Of

Diurnal changes in hormonal concentrations were determined at various times during sexual development and during the ovulatory cycle of Khaki Campbell ducks raised either on a constant photoperiod of 16 h light: 8 h darkness (16L : 8D) or on a schedule which simulated natural changes in daylength. The ovulatory cycle of the latter group was studied when there were 11 h light/day and daylength was increasing. In the laying duck concentrations of LH and progesterone in the plasma rose simultaneously between 7 and 4 h before ovulation and oviposition. Preovulatory concentrations of LH and progesterone in ducks subjected to photoperiods of 16L : 8D and 11L : 13D started to increase at the onset of darkness and 2 h after the onset of darkness respectively. In ducks maintained on 16L : 8D there was a rise in the concentration of corticosterone in the plasma at the onset of darkness to attain a maximum just before the onset of light. The temporal relationship of the peak of secretion of corticosterone to the cycle of light and darkness changed during sexual development of ducks raised on 16L : 8D with a 6-h advance in the phase of the rhythm between 11 weeks of age and the onset of egg laying. Highest progesterone concentrations during the day tended to coincide with the maximal secretion of corticosterone. A monophasic diurnal rhythm in the secretion of corticosterone in 11-week-old ducks maintained on natural daylength had disappeared by 15 weeks and was not re-established by 25 weeks of age. A diurnal variation in the plasma concentration of LH was not observed in the ducks maintained on 16L : 8D, although night-time LH concentrations tended to be higher than day-time concentrations in ducks raised on natural daylength. This difference was significant at 11 weeks, and at 15, 19 and 22 weeks changes in the plasma concentrations of LH during the night tended to parallel those of corticosterone.

CHANGES IN THE CONCENTRATION OF LUTEINIZING HORMONE IN PLASMA DURING DEVELOPMENT IN THE GUINEA-PIG

1975 ◽  
Vol 64 (3) ◽  
pp. 511-520 ◽  
Author(s):  
B. T. DONOVAN ◽  
M. B. TER HAAR ◽  
A. N. LOCKHART ◽  
P. C. B. MACKINNON ◽  
J. M. MATTOCK ◽  
...  
Keyword(s):  
Plasma Concentration ◽  
Luteinizing Hormone ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Plasma Concentrations ◽  
Maternal Plasma ◽  
Significant Rise ◽  
Cross Reaction ◽  
Blood Collection ◽  
Postnatal Life

SUMMARY The concentration of LH in the plasma of guinea-pigs from day 50 of gestation to day 45 of postnatal life was assayed by radioimmunoassay utilizing a cross-reaction with anti-ovine LH antiserum. The effect of gonadectomy in infancy and in the adult upon the plasma concentration of LH was also studied. The LH concentration in the plasma of male or female foetuses was high immediately prenatally and fell at birth. High levels of LH were again detected in male, with a lesser increase in female, guinea-pigs over the first 10 days postnatally. Maternal plasma concentrations of LH remained consistently low. Removal of the gonads on days 0, 5, 10, 15, 25 or 35 of postnatal life, followed by blood collection at autopsy 10 days later, caused a significant rise in plasma LH content at all ages. The rise in plasma LH after gonadectomy in adults was less marked in male than in female guinea-pigs.

Short-term kinetics of LRH-induced LH-release in the long-term ovariectomized rat

1982 ◽  
Vol 99 (2) ◽  
pp. 187-194 ◽  
Author(s):  
T. R. Koiter ◽  
N. Pols-Valkhof ◽  
G. A. Schuiling
Keyword(s):  
Luteinizing Hormone ◽  
Initial Phase ◽  
Plasma Concentrations ◽  
Compartment Model ◽  
Ovx Rats ◽  
Lh Release ◽  
Series Of Experiments ◽  
Lh Secretion ◽  
Very High

Abstract. In a first series of experiments plasma concentrations of luteinizing hormone (LH) were measured at 10 min intervals during 2 h of constant rate infusion of luteinizing hormone-releasing hormone (LRH; 104 ng/ h) in phenobarbitone-anaesthetized long-term ovariectomized (OVX) rats, treated with oil or oestradiol-benzoate (OeB). From these data the mean LH secretion rates during the sampling intervals were calculated using a one-compartment model for the elimination of LH from the plasma. It was found in the OeB-primed OVX rats that during the initial 30–40 min of infusion the LH release is high but constant. Thereafter it shows a further increase. In the oil-treated OVX rats a similar biphasic LH release pattern was found, but in these animals it was preceded by an initial phase of very high LH release, lasting a few minutes. In another series of experiments a second LRH infusion (again 104 ng/h) was given to OeB-primed OVX rats, starting 1.5 h after the discontinuation of a first LRH infusion lasting either 1, 3.5 or 20 h. The resulting secondary LH responses were smaller the longer the first infusion had lasted, but the LH secretion pattern was similar with all three time schedules and resembled the triphasic pattern observed during the first experiment in the oil-treated OVX rats, rather than the biphasic pattern of the OeB-primed OVX rats. These results indicate that the LH response to LRH of OVX rats (either treated with OeB or oil), like that of the cyclic rats, exhibits a phase of constant LH release. It is generally assumed that during this period conditions, necessary for the subsequent further increase of the LH secretion, are generated. It is concluded that these conditions largely disappear during a 1.5 h non-stimulus period. It is also concluded that the short initial phase of very high LH secretion is due to recent exposure of the LH-secretory system to stimulatory amounts of LRH.

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