Endocrine correlates of territoriality, breeding stage, and body molt in free-living willow ptarmigan of both sexes

1990 ◽  
Vol 68 (10) ◽  
pp. 2130-2134 ◽  
Author(s):  
Susan J. Hannon ◽  
John C. Wingfield
Keyword(s):  
Luteinizing Hormone ◽  
Aggressive Behaviour ◽  
Follicle Stimulating Hormone ◽  
Plasma Concentrations ◽  
Egg Laying ◽  
Plasma Testosterone ◽  
Willow Ptarmigan ◽  
Free Living ◽  
Brood Rearing ◽  
Egg Formation

Concentrations of plasma testosterone, estradiol, corticosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were measured by radioimmunoassay in wild willow ptarmigan (Lagopus lagopus) of both sexes over the breeding season. In males, plasma concentrations of testosterone and LH increased once they became territorial, and this was paralleled by increases in comb size and initiation of molt into courtship plumage. A decline of testosterone and circulating LH levels during late territoriality and egg laying coincided with molt into summer plumage. FSH titers did not vary significantly through the season, but there was a trend for higher levels during the territorial period. Plasma concentrations of corticosterone were highest during pre- and late territoriality and brood rearing. In females, testosterone levels were about 13 times lower than in males and did not vary significantly, whereas LH was high from pre- to mid-territoriality and again in the brood season. Elevated LH levels may be correlated with aggressive behaviour in females. FSH and estradiol concentrations were highest during the period of egg formation. Corticosterone was correlated with chase time in both sexes.

Plasma Testosterone, Luteinizing Hormone and Follicle-Stimulating Hormone one Day after Vasectomy

Andrologia ◽  
2009 ◽  
Vol 11 (4) ◽  
pp. 294-296 ◽  
Author(s):  
R.E. JOHNSONBAUGH ◽  
L.P. GEORGES ◽  
C.L. CZERWINSKI ◽  
M. EDSON
Keyword(s):  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Plasma Testosterone ◽  
Stimulating Hormone

EFFECTS OF FOLLICLE-STIMULATING HORMONE AND LUTEINIZING HORMONE ON PLASMA TESTOSTERONE LEVELS IN HYPOPHYSECTOMIZED AND IN INTACT IMMATURE AND ADULT MALE RATS

1974 ◽  
Vol 61 (2) ◽  
pp. 193-198 ◽  
Author(s):  
S. EL SAFOURY ◽  
A. BARTKE
Keyword(s):  
Luteinizing Hormone ◽  
Adult Male ◽  
Follicle Stimulating Hormone ◽  
Seminal Vesicles ◽  
Male Rats ◽  
Plasma Testosterone ◽  
Adult Rats ◽  
Testosterone Levels ◽  
Hypophysectomized Rats ◽  
Stimulating Hormone

SUMMARY The effects of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) on plasma testosterone levels were examined in hypophysectomized and in intact immature and adult male rats. The animals were injected with saline, LH, FSH, or both gonadotrophins twice daily for 3·5 days and were killed 3 h after the last injection. Plasma testosterone levels were measured by radioimmunoassay. In immature hypophysectomized rats, plasma testosterone levels were not changed by treatment with LH, FSH or LH plus FSH. The weight of the testes and of the seminal vesicles was increased only in animals injected with both LH and FSH. In adult hypophysectomized rats, LH caused the expected increase in plasma testosterone levels, while FSH injected alone had no effect. Plasma testosterone levels in rats treated with 5 μg LH and 20 μg FSH were significantly greater than those in animals given 5 μg LH alone. However, the same dose of FSH did not potentiate the action of 25 μg LH on plasma testosterone levels. In adult hypophysectomized rats the weight of testes was not affected by any of the treatments. The weight of the seminal vesicles was increased by the higher dose of LH and addition of FSH caused no further increase. In intact immature and adult rats plasma testosterone levels and the weight of testes were not changed by any of the treatments. Seminal vesicle weight was increased only in adult rats treated with the higher dose of LH together with FSH. The results demonstrate that FSH potentiates the action of low doses of LH on plasma testosterone levels in adult hypophysectomized rats and suggest that FSH may be involved in the regulation of androgen secretion by the rat testis.

Effect of various anaesthetics on resting plasma concentrations of luteinizing hormone, follicle-stimulating hormone and prolactin in ovariectomized ewes

1983 ◽  
Vol 98 (1) ◽  
pp. 79-89 ◽  
Author(s):  
I. J. Clarke ◽  
B. W. Doughton
Keyword(s):  
Seasonal Variation ◽  
Luteinizing Hormone ◽  
Breeding Season ◽  
Follicle Stimulating Hormone ◽  
Plasma Concentrations ◽  
Pulse Amplitude ◽  
Experimental Series ◽  
Plasma Prolactin ◽  
Pulsatile Secretion ◽  
Induction Of Anaesthesia

Effects of various anaesthetics on plasma LH, FSH and prolactin levels were studied in ovariectomized ewes. In the first experimental series, conducted between June and November (late breeding season, early anoestrous season), the following treatments were given: saline (i.v.) (n = 7); single thiopentone injection (i.v.) (n = 4); induction of anaesthesia for 2 h with thiopentone (n = 5), ketamine/thiopentone mixture (n = 6), Alphathesin (n = 6) or induction with thiopentone and maintenance with halothane (n = 6). The major findings were: (1) halothane anaesthesia reduced mean plasma LH levels by preventing pulsatile secretion of LH; (2) Alphathesin had the least effect on tonic LH concentration; (3) a single thiopentone injection did not affect LH levels; (4) continuous thiopentone anaesthesia increased LH pulse amplitude; (5) plasma FSH concentration was not affected by any of the treatments; (6) ketamine/thiopentone-induced and Alphathesin-induced anaesthesia increased plasma prolactin levels. In a second experimental series four ovariectomized ewes were anaesthetized with thiopentone for 3 h in January. In contrast to the results obtained with thiopentone in August, treatment in January reduced plasma LH pulse amplitude and mean plasma LH levels. These latter results support the hypothesis that there may be seasonal variation in responses to barbiturate anaesthesia.

LEVELS OF LUTEINIZING HORMONE, FOLLICLE-STIMULATING HORMONE, TESTOSTERONE AND DIHYDROTESTOSTERONE IN THE CIRCULATION OF SEXUALLY MATURING INTACT MALE RATS AND AFTER ORCHIDECTOMY AND EXPERIMENTAL BILATERAL CRYPTORCHIDISM

1975 ◽  
Vol 66 (2) ◽  
pp. 183-193 ◽  
Author(s):  
D. GUPTA ◽  
K. RAGER ◽  
J. ZARZYCKI ◽  
M. EICHNER
Keyword(s):  
Plasma Levels ◽  
Follicle Stimulating Hormone ◽  
Plasma Concentrations ◽  
Gonadal Steroids ◽  
Male Rats ◽  
Plasma Testosterone ◽  
Dynamic Feedback ◽  
Gonadal Steroid ◽  
Intact Male ◽  
Bilateral Cryptorchidism

SUMMARY Plasma concentrations of LH, FSH, testosterone and dihydrotestosterone (DHT) have been measured in normal sexually maturing male rats from the age of 16–90 days. Between 16 and 25 days plasma testosterone levels were low, but rose suddenly on day 26. A similar increment occurred at the same time in plasma DHT levels, but this steroid reached its peak concentration later than testosterone. Plasma LH levels rose steadily from day 25 onwards, reaching their highest values on day 30. A marked increase in FSH levels was found on day 16, and a peak was reached on day 33 followed by a decline to a level characteristic of the adult. In addition, plasma levels of all these hormones were estimated in the male animals at various stages of development after orchidectomy and cryptorchidism. Four days after operation, the plasma levels of LH and FSH in the orchidectomized animals reached higher levels than those found in the intact animals, indicating the existence of a dynamic feedback relationship before puberty between gonadal steroids and pituitary gonadotrophic secretion. However, results from the experimental bilaterally cryptorchid animals, suggested that the gonadal steroid–gonadotrophic feedback relationship could not be the only factor initiating puberty.

scholarly journals Plasma Luteinizing Hormone and Testosterone Concentrations in Different Breeds of Young Beef Bulls in the Tropics

1983 ◽  
Vol 36 (6) ◽  
pp. 545 ◽  
Author(s):  
TB Post ◽  
BM Bindon
Keyword(s):  
Luteinizing Hormone ◽  
Plasma Concentrations ◽  
Plasma Testosterone ◽  
Beef Bulls ◽  
The Tropics

Plasma concentrations of luteinizing hormone (LH) and testosterone were measured at 3, 8 and 11 months of age in 48 Africander cross (AX), 24 Brahman cross (BX), 21 Hereford-Shorthorn, selected (HSS) and 14 Hereford-Shorthorn, random-bred (HSR) bulls. In all breeds plasma LH was lower (P<O� 01) at 8 months (1�7 ng/ml) than at 3 months (2�6 ng/ml) or at 11 months (2�6 ng/ml). Over all ages there were no differences among breeds in mean plasma LH (AX 2�4, BX 2�4, HSS 1�8, HSR 2�2 ng/ml) and no breed X age interactions. In contrast, plasma testosterone increased significantly (P<O� 01) with age and at a faster rate in the AX breed, resulting in a significant (P<O� 05) breed X age interaction. Testosterone concentrations, though similar among breeds at 3 months of age (0�45 ng/ml), were much higher (P<O� 01) by 11 months in AX (2�56 ng/ml) than in BX (1�30 ng/ml), HSS (0�78 ng/ml) or HSR (0�66 ng/ml) bulls.

scholarly journals Effect of a luteinizing hormone releasing hormone agonist given during combination chemotherapy on posttherapy fertility in male patients with lymphoma: preliminary observations

Blood ◽  
1985 ◽  
Vol 65 (4) ◽  
pp. 832-836 ◽  
Author(s):  
DH Johnson ◽  
R Linde ◽  
JD Hainsworth ◽  
W Vale ◽  
J Rivier ◽  
...  
Keyword(s):  
Luteinizing Hormone ◽  
Combination Chemotherapy ◽  
Follicle Stimulating Hormone ◽  
Plasma Testosterone ◽  
Normal Range ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Chemotherapy Administration ◽  
Male Patients ◽  
Lower Limit Of Normal

Six men undergoing potentially curative chemotherapy for advanced lymphomas received daily injections (50 micrograms) of an analogue of luteinizing hormone releasing hormone (LH-RHa) in an attempt to protect posttreatment gonadal function. The median duration of combined LH-RHa- chemotherapy administration was 25 weeks (range, 14 to 31 weeks). During the simultaneous administration of LH-RHa and chemotherapy, plasma testosterone levels decreased to subnormal levels, while both follicle-stimulating hormone (FSH) and luteinizing hormone levels declined to the lower limit of normal. All subjects became oligospermic or azoospermic within eight weeks of starting treatment. Following discontinuation of chemotherapy and LH-RHa, both plasma testosterone and LH promptly increased and stabilized within the normal range. FSH progressively increased to a level well above the normal range. Only one patient has recovered evidence of active spermatogenesis at 84 weeks postcessation of chemotherapy. No untoward side effects due to LH- RHa were experienced. Although LH-RHa can be administered safely during combination chemotherapy, no improvement in posttreatment fertility has yet been demonstrated.

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