CHANGES IN PLASMA CONCENTRATIONS OF LUTEINIZING HORMONE AFTER INJECTION OF PROGESTERONE AT VARIOUS TIMES DURING THE OVULATORY CYCLE OF THE DOMESTIC HEN (GALLUS DOMESTICUS)

1975 ◽  
Vol 67 (1) ◽  
pp. 59-70 ◽  
Author(s):  
SUSAN C. WILSON ◽  
P. J. SHARP
Keyword(s):  
Luteinizing Hormone ◽  
Plasma Concentrations ◽  
Gallus Domesticus ◽  
Ovulatory Cycle ◽  
Lh Surge ◽  
Incremental Change ◽  
The Mean ◽  
Domestic Hen

SUMMARY Changes in plasma LH concentrations after i.m. injections of 0·5 mg progesterone/kg at various stages of the ovulatory cycle were measured by radioimmunoassay. Four types of response were observed. (1) When the steroid was injected between 4 h after and 12 h before an ovulation, LH levels started to rise after 15–45 min and reached peak values within 90–120 min. The mean maximal incremental change in the level of LH was 1·58 ± 0·10 (s.e.m.) ng/ml (n = 37). (2) In contrast, when progesterone was injected 12–8 h before ovulation, i.e. immediately before a spontaneous pre-ovulatory LH surge, the resulting mean maximal incremental change in LH level, 0·79 ± 0·12 ng/ml (n = 9), was significantly smaller (P < 0·001). (3) If progesterone was injected 8–4 h before ovulation, i.e. when pre-ovulatory LH levels were rising, they immediately started to rise more rapidly and reached peak values within 45 min. The maximal incremental change in the level of LH under these circumstances, 2·34 ± 0·20 ng/ml (n = 12), was significantly greater (P < 0·001 in both cases) than the changes observed in the responses 1 and 2 described above. (4) Levels of LH generally showed no incremental change in response to injections of progesterone given 4–0 h before ovulation, i.e. when pre-ovulatory LH levels were falling. It was concluded that the type of change in plasma LH levels induced by progesterone depended upon the stage of the ovulatory cycle at which the steroid was injected.

CONTROL OF THE PREOVULATORY SURGE OF LUTEINIZING HORMONE IN THE HEN (GALLUS DOMESTICUS): THE ROLE OF PROGESTERONE AND ANDROGENS

1978 ◽  
Vol 77 (1) ◽  
pp. 57-65 ◽  
Author(s):  
J. B. WILLIAMS ◽  
P. J. SHARP
Keyword(s):  
Luteinizing Hormone ◽  
Dark Period ◽  
Ovarian Follicle ◽  
Gallus Domesticus ◽  
Ovulatory Cycle ◽  
Blood Samples ◽  
Lh Surge ◽  
Before And After ◽  
Small Rise

Peripheral blood samples were taken from laying hens at frequent intervals during various periods of the ovulatory cycle in order to detect small changes in the concentrations of progesterone and androgen which might be important in initiating the preovulatory release of LH. Blood samples were taken from seven hens at 1 h intervals for 3 h when the ovary contained a mature (C1) follicle and on another occasion, when the largest ovarian follicle was immature. The concentrations of progesterone and androgens in the plasma were 30% higher when there was a mature C1 follicle present in the ovary than when there was not, but this increase was significant (P < 0·05) only for progesterone. The concentrations of progesterone and androgens were also measured in blood samples taken at 30 min intervals during the 3 h before and after the initiation of the first preovulatory LH surge of a sequence. The hens were kept on a lighting schedule of 14 h light/day and the first LH surge of a sequence was initiated at the beginning of the dark period. Just after the onset of darkness there was a small increase in the concentration of LH in the plasma and a subsequent, larger preovulatory release of LH. The first increase in the level of LH was associated with a small rise in the concentrations of androgens and progesterone in the plasma while the preovulatory release of LH was accompanied by a much larger increase in the secretion of these steroids. It is proposed that the increase in the level of LH in the plasma at the onset of darkness stimulates the maturing ovarian follicles to secrete progesterone and androgens and that the quantities of these steroids secreted (particularly of progesterone) depends on the maturity of the largest ovarian follicle. If the largest ovarian follicle is mature, then the increase in the level of LH in the plasma associated with the onset of darkness stimulates the secretion of a quantity of progesterone sufficient to cause the preovulatory surge of LH. A diurnal increase in the concentration of LH in the plasma could, therefore, be responsible for timing the preovulatory surges of LH so that they are only initiated at night.

Evidence for the involvement of central catecholaminergic mechanisms in mediating the preovulatory surge of luteinizing hormone in the domestic hen

1982 ◽  
Vol 94 (2) ◽  
pp. 295-304 ◽  
Author(s):  
P. G. Knight ◽  
S. C. Wilson ◽  
R. T. Gladwell ◽  
F. J. Cunningham
Keyword(s):  
Steady State ◽  
Luteinizing Hormone ◽  
Pharmacological Treatments ◽  
Ovulatory Cycle ◽  
Lh Surge ◽  
Dopaminergic Mechanisms ◽  
Lh Release ◽  
Noradrenaline And Adrenaline ◽  
Domestic Hen ◽  
Catecholaminergic Mechanisms

The effects of various pharmacological treatments, designed to perturb central catecholaminergic neurotransmission, on the pattern of LH release during the preovulatory period in the domestic hen were studied. Treatment of hens with either l-dihydroxyphenylalanine or diethyldithiocarbamate which raised the concentration of dopamine in the hypothalamus by 42 and 110% respectively, or with apomorphine, attenuated the preovulatory surge of LH. In contrast, treatment with either α-methyl-p-tyrosine which produced a 65% decline in the concentration of dopamine in the hypothalamus without affecting the concentrations of noradrenaline or adrenaline or treatment with pimozide did not affect the LH surge. While treatment with propranolol was similarly ineffective, phenoxybenzamine attenuated the LH surge to a marked extent. These observations suggest that the preovulatory surge of LH in the hen is influenced by facilitatory α-adrenergic and inhibitory dopaminergic mechanisms. Evidence to corroborate these findings was sought by determining the steady-state concentrations of dopamine, noradrenaline and adrenaline in five discrete diencephalic regions of the hen throughout the ovulatory cycle.

Changes in 3β-hydroxy-Δ5-steroid dehydrogenase activity in granulosa tissue during the ovulatory cycle of the laying hen (Gallus domesticus)

1985 ◽  
Vol 106 (3) ◽  
pp. 269-273 ◽  
Author(s):  
D. G. Armstrong
Keyword(s):  
Enzyme Activity ◽  
Dehydrogenase Activity ◽  
Domestic Fowl ◽  
Ovarian Follicle ◽  
Laying Hen ◽  
Gallus Domesticus ◽  
Ovulatory Cycle ◽  
Lh Surge ◽  
Maximal Plasma ◽  
Steroid Dehydrogenase

ABSTRACT The object of this study was to examine changes in the activity of granulosa 3β-hydroxy-Δ5-steroid dehydrogenase during the ovulatory cycle of the domestic fowl. The enzyme activity in granulosa tissue from the largest follicle increased significantly during the period 8–14 h before an expected ovulation. The increase in activity occurs before the preovulatory surge of LH and near the time of lights off. During the 4–8 h period before an ovulation, i.e. the time of maximal plasma LH concentrations, 3β-hydroxy-Δ5-steroid dehydrogenase activity decreased in granulosa tissue from the largest follicle. This observation is explained by proposing that the enzyme is inhibited by the large amounts of progesterone found in the tissue at this time. The results indicate that important biochemical changes are taking place within granulosa tissue of the largest ovarian follicle before the preovulatory LH surge. J. Endocr. (1985) 106, 269–273

scholarly journals Comparative changes in plasma concentrations of progesterone, oestradiol and LH during the ovulatory cycle in a multiple ovulating male line and a single ovulating traditional line of turkeys

Reproduction ◽  
2002 ◽  
pp. 127-133 ◽  
Author(s):  
S Buchanan ◽  
GW Robertson ◽  
PM Hocking
Keyword(s):  
Peak Plasma ◽  
Ovarian Tissue ◽  
Plasma Concentrations ◽  
High Growth ◽  
Correlated Response ◽  
Ovulatory Cycle ◽  
Plasma Progesterone ◽  
Multiple Ovulation ◽  
Male Line ◽  
The Mean

The aim of this study was to compare the profile of circulating concentrations of LH, progesterone and oestradiol in a multiple ovulating male line with that of a single ovulating line of traditional turkeys. Plasma samples from seven traditional and 12 male-line turkeys were obtained every 3 h for 36 h. Male-line and traditional turkeys had single peaks of LH and progesterone that were of similar duration in both lines. The mean height of the plasma peaks of LH and progesterone were similar in the two lines and there was no detectable peak plasma oestrogen concentration. Mean plasma concentrations of LH and oestrogen were higher in single compared with multiple ovulating turkeys, whereas there were no differences in mean plasma progesterone concentrations. The results indicate that the multiple ovulation state in genetically selected high-growth lines of turkey may be the result of a correlated response in the steroidogenic capacity of ovarian tissue associated with low plasma concentrations of oestrogen rather than of a disturbance in the hormone profile of the ovulatory cycle.

A COMPARISON OF VARIATIONS IN PLASMA LUTEINIZING HORMONE CONCENTRATIONS IN MALE AND FEMALE DOMESTIC CHICKENS (GALLUS DOMESTICUS) FROM HATCH TO SEXUAL MATURITY

1975 ◽  
Vol 67 (2) ◽  
pp. 211-223 ◽  
Author(s):  
P. J. SHARP
Keyword(s):  
Luteinizing Hormone ◽  
Reproductive Performance ◽  
Sexual Maturity ◽  
Gallus Domesticus ◽  
Parallel Study ◽  
Stages Of Development ◽  
Male And Female ◽  
The Mean ◽  
Lh Secretion

SUMMARY Changes in plasma LH concentrations were followed in chickens of both sexes from hatch to sexual maturity using a radioimmunoassay. Mean levels of LH were lower in the females than in the males at all stages of development. These levels rose rapidly in both sexes during the first week after hatch to maxima of 6·5 ± 1·2 (s.e.m.) ng/ml (n = 6) in the males and 4·6 ± 0·6 ng/ml (n = 6) in the females. Thereafter levels of the hormone in the circulation stabilized in the males but fell over a period of 1 or 2 weeks in the females to 2·5–3 ng/ml. Plasma LH levels started to rise steeply in both sexes when they were between 16 and 19 weeks old at the same time as there was an increase in the rate of comb growth. Afterwards in six of the males studied in detail the mean plasma LH level rose significantly (P < 0·01) over a period of 5–8 weeks from 8·1 ± 1·2 to 13·2 ± 1·9 ng/ml. In a parallel study on six females the rate of LH secretion increased for approximately 3 weeks and then decreased for about the same period forming a prepubertal LH peak. The first eggs were laid between 22 and 25 weeks of age when mean plasma LH levels had fallen to about 1·8 ng/ml. The mean plasma LH level in these hens when they were laying (1·8 ± 0·3 ng/ml) was significantly lower (P < 0·01) than when they were sexually immature (2·7 ± 0·3 ng/ml). The duration of the period of rapid comb growth in each bird was closely related in the males to the time during which prepubertal LH levels were rising rapidly, and in the females to the duration of the prepubertal LH peak. Differences in mean plasma LH concentrations in individual birds of either sex before the onset of puberty appeared to be related to subsequent reproductive performance.

THE PLASMA CONCENTRATIONS OF TESTOSTERONE AND LH DURING THE OVULATION CYCLE OF THE HEN (GALLUS DOMESTICUS)

1977 ◽  
Vol 84 (2) ◽  
pp. 357-366 ◽  
Author(s):  
R. J. Etches ◽  
F. J. Cunningham
Keyword(s):  
Luteinizing Hormone ◽  
Maximum Concentration ◽  
Plasma Concentrations ◽  
Gallus Domesticus ◽  
Baseline Concentrations ◽  
Basal Concentration

ABSTRACT The plasma concentrations of testosterone and luteinizing hormone (LH) were measured by radioimmunoassay during the ovulation cycle of the hen. The baseline concentrations of testosterone were 100 to 250 pg/ml and the maximum concentration of 904 pg/ml was observed 8 h before ovulation. The maximum pre-ovulatory concentration of LH of 2.0 ng/ml, which was approximately twice the basal concentration, was observed 6 h before ovulation. The possibility that testosterone is the ovarian excitation hormone which initiates the ovulation-inducing surge of LH is discussed.

THE INTERRELATIONSHIP BETWEEN PROGESTERONE AND LUTEINIZING HORMONE DURING THE OVULATION CYCLE OF THE HEN (GALLUS DOMESTICUS)

1976 ◽  
Vol 71 (1) ◽  
pp. 51-58 ◽  
Author(s):  
R. J. ETCHES ◽  
F. J. CUNNINGHAM
Keyword(s):  
Luteinizing Hormone ◽  
Plasma Concentrations ◽  
Physiological Role ◽  
Follicular Development ◽  
Gallus Domesticus ◽  
Luteinizing Hormone Releasing Hormone ◽  
Progesterone Secretion ◽  
Lh Rh ◽  
Premature Ovulation

SUMMARY The existence of a circadian rhythm in the sensitivity of the hypothalamus of the laying hen to stimulation by progesterone was investigated by injecting 0·5 mg progesterone subcutaneously during the proposed period of maximum insensitivity. Following this treatment increases in plasma concentrations of both LH and progesterone were observed which were comparable to the spontaneous preovulatory rises in the plasma levels of the hormones. The ability of either progesterone or luteinizing hormone releasing hormone (LH-RH) to induce premature ovulation varied according to the stage of follicular development. Neither hormone was more than 28% effective when injected within 6·5 h of the previous ovulation, whereas both hormones were 100% effective approximately 27 h after the terminal ovulation of a clutch sequence. Failure to ovulate in response to LH-RH given 6·5 h after ovulation was associated with a lack of progesterone secretion. Both LH and progesterone were secreted when ovulation was induced by injections of either LH-RH or progesterone, and LH was secreted in response to progesterone given 6·5 h after ovulation. These results demonstrate that progesterone stimulates the secretion of LH and LH stimulates the secretion of progesterone. The precise physiological role of these two hormones, however, was not established.

CHANGES IN THE PLASMA CONCENTRATIONS OF LUTEINIZING HORMONE, PROGESTERONE, OESTRADIOL AND TESTOSTERONE AND IN THE BINDING OF FOLLICLE-STIMULATING HORMONE TO THE THECA OF FOLLICLES DURING THE OVULATION CYCLE OF THE HEN (GALLUS DOMESTICUS)

1981 ◽  
Vol 91 (1) ◽  
pp. 11-22 ◽  
Author(s):  
R. J. ETCHES ◽  
K. W. CHENG
Keyword(s):  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Plasma Concentrations ◽  
Gallus Domesticus ◽  
Interstitial Tissue ◽  
Follicular Maturation ◽  
Ovarian Stroma ◽  
Pituitary Glands ◽  
Two Peaks ◽  
Second Peak

The changes in the binding of FSH during follicular maturation were examined in the hen using 125I-labelled bovine FSH (bFSH) and unlabelled bFSH. The binding of 125I-labelled bFSH was not inhibited by bovine LH or chicken LH but was inhibited by extracts of chicken pituitary glands. The ovarian stroma, which contained both interstitial tissue and small follicles, bound the greatest amount of FSH. As the follicles progressed through the yolk-filled hierarchy of maturation, they bound decreasing amounts of FSH. In the two largest follicles of the hierarchy, there was a significant increase in the binding of FSH 12–16 h before ovulation. There were two peaks in the concentrations of LH; a preovulatory peak occurred 4–6 h before ovulation and a second peak occurred 14–16 h before ovulation. Plasma concentrations of testosterone, oestradiol and progesterone began to rise 9, 8 and 6 h, respectively, before ovulation. These data are consistent with the hypothesis that changes in the gonadotrophin concentration and binding regulate the order of the follicular hierarchy and the onset of preovulatory steroidogenesis in the hen.

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