Seasonal variation in plasma LH, FSH, prolactin, and testosterone concentrations in adult male white-tailed deer

1978 ◽  
Vol 56 (1) ◽  
pp. 121-127 ◽  
Author(s):  
R. E. Mirarchi ◽  
B. E. Howland ◽  
P. F. Scanlon ◽  
R. L. Kirkpatrick ◽  
L. M. Sanford
Keyword(s):  
Binding Assay ◽  
Follicle Stimulating Hormone ◽  
Late Winter ◽  
Protein Binding Assay ◽  
Antler Growth ◽  
Competitive Protein Binding Assay ◽  
Competitive Protein Binding ◽  
The Relationship ◽  
Wild Deer ◽  
Androgen Levels

Blood samples were collected monthly from captive and wild adult (12 months old or older) male white-tailed deer (Odocoileus virginianus) over 1 year in southwest Virginia. Plasma was assayed for luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin (PRL), and testosterone (T) using radioimmunoassays. LH and T levels for the captive and wild deer were essentially similar and followed a distinct annual cycle. LH concentrations (nanograms per millilitre) peaked earlier (October, captive, 4.5 ± 1.8 (mean ± standard error); September, wild, 3.3 ± 0.9) than T concentrations (nanograms per millilitre) (November, captive, 13.3 ± 2.7; November, wild, 23.7 ± 7.8) and dropped off sharply prior to, or concomitant with, T concentrations. LH and T levels were lowest during the late winter and spring. T concentrations were closely correlated with androgen levels (Mirarchi, R. E., P. F. Scanlon, R. L. Kirkpatrick, and C. B. Schreck. J. Wildl. Manage. 41: 178–183 (1977)) determined by competitive protein binding assay. Mean PRL and FSH concentrations in wild and captive deer also displayed seasonal variations. Prolactin concentrations (nanograms per millilitre) were highest in May (147.5 ± 0.0) and lowest in November while FSH levels (nanograms per millilitre) peaked in September (180.2 ± 22.4) and were lowest in March. Differences in hormone concentrations between deer and sheep, and the relationship between PRL and antler growth and FSH and spermatozoan production, are discussed.

HORMONAL REQUIREMENTS FOR THE MAINTENANCE OF LUTEAL FUNCTION IN HYPOPHYSECTOMIZED, PSEUDOPREGNANT RATS

1973 ◽  
Vol 56 (3) ◽  
pp. 421-429 ◽  
Author(s):  
MASAOMI TAKAYAMA ◽  
G. S. GREENWALD
Keyword(s):  
Plasma Levels ◽  
Binding Assay ◽  
Follicle Stimulating Hormone ◽  
Luteal Function ◽  
Peripheral Plasma ◽  
Protein Binding Assay ◽  
Competitive Protein Binding Assay ◽  
Competitive Protein Binding ◽  
Higher Doses

SUMMARY Pseudopregnant rats with traumatized uteri were hypophysectomized on day 6 and injected with various hormones over the next 4 days. Luteal function was assessed on day 10 of pseudopregnancy by weighing deciduomata and determining luteal and plasma levels of progesterone by a competitive protein-binding assay. Daily treatment with 0·25 mg prolactin restored plasma and luteal levels to the values of intact pseudopregnant animals; however, the deciduomata weighed only 55% of control values. Combining oestrone with prolactin restored deciduomata weight to control values without affecting peripheral progesterone levels. Either 200 μg of follicle-stimulating hormone (FSH) or 5 μg luteinizing hormone (LH) could be substituted for oestrone, in conjunction with prolactin, to increase deciduomata weight to control values. Moreover, the combination of prolactin with FSH or LH significantly increased peripheral plasma levels of progesterone beyond the effects of prolactin alone. Higher doses of LH were luteolytic as shown by decreased deciduomata weight and considerable variation in plasma and luteal values of progesterone. LH given alone — either in saline or polyvinyl pyrrolidine — failed to maintain any of the parameters of luteal activity mentioned above. The results reaffirm the primacy of prolactin in vivo as the principal luteotrophic hormone of the rat and indicate that selected doses of LH or FSH play an additive role in further increasing peripheral levels of progesterone.

TESTOSTERONE AND DIHYDROTESTOSTERONE CONCENTRATIONS IN THE FLUID MILIEU OF SPERMATOZOA IN THE REPRODUCTIVE TRACT OF THE BULL

1973 ◽  
Vol 74 (1) ◽  
pp. 186-200 ◽  
Author(s):  
Venkataseshu K. Ganjam ◽  
Rupert P. Amann
Keyword(s):  
Mass Spectrometry ◽  
Seminal Plasma ◽  
Reproductive Tract ◽  
Binding Assay ◽  
Rete Testis ◽  
Protein Binding Assay ◽  
Highly Sensitive ◽  
Competitive Protein Binding Assay ◽  
Competitive Protein Binding ◽  
Isolated Compound

ABSTRACT Total 17β-hydroxyandrogen concentrations were determined using a competitive protein binding assay, for bovine reproductive fluids. Rete testis fluid and cauda epididymal plasma were separated from the spermcontaining fluids obtained through cannulae from conscious bulls. Al-through the concentration of total 17β-hydroxyandrogens in rete testis fluid was similar (P > 0.05) to that in cauda epididymal plasma (25 and 19 ng/ml), both fluids contained higher (P < 0.01) androgen concentrations than seminal plasma, accessory sex gland fluid or serum from peripheral blood (3–5 ng/ml). However, since the amount of cauda epididymal plasma recovered was much less than for rete testis fluid (0.25 vs 35 ml/day), cauda epididymal plasma contained less than 1 % of the total 17β-hydroxyandrogens which entered the epididymis in rete testis fluid (5 vs 883 ng/day). Testosterone and/or dihydrotestosterone were isolated from the reproductive fluids by Sephadex LH-20 chromatography and quantified by a simple, specific and highly sensitive microassay. Dihydrotestosterone was found only in cauda epididymal plasma (14 ng/ml); identification of the isolated compound was confirmed by mass spectrometry. Dihydrotestosterone accounted for 52% of the 17β-hydroxyandrogens in cauda epididymal plasma while 23 % was testosterone. Testosterone represented 70 % of the 17β-hydroxyandrogens in rete testis fluid and 91 % of those in blood serum. Physiological implications of this shift in androgen balance are discussed.

A Simplified competitive protein-binding assay for 25-hydroxycalciferol

1976 ◽  
Vol 68 (2) ◽  
pp. 99-105 ◽  
Author(s):  
B. Garcia-Pascual ◽  
A. Peytremann ◽  
B. Courvoisier ◽  
D.E.M. Lawson
Keyword(s):  
Protein Binding ◽  
Binding Assay ◽  
Protein Binding Assay ◽  
Competitive Protein Binding Assay ◽  
Competitive Protein Binding

A Competitive Protein-Binding Assay for 25-Hydroxycholecalciferol

1975 ◽  
Vol 17 (2) ◽  
pp. 57-57
Author(s):  
Yoshiki Seino ◽  
Tsunesuke Shimotsuji ◽  
Shintaro Okada ◽  
Teisuke Hiejima ◽  
Chiiko Ikehara ◽  
...  
Keyword(s):  
Protein Binding ◽  
Binding Assay ◽  
Protein Binding Assay ◽  
Competitive Protein Binding Assay ◽  
Competitive Protein Binding ◽  
25 Hydroxycholecalciferol
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