Peripheral plasma testosterone concentration and sexual behavior in young prenatally stressed boars

ABSTRACT The mean peripheral plasma concentration of oestradiol was found to be increased in 3 dogs with Sertoli cell tumours and in 3 dogs with seminomas, whereas the plasma testosterone showed no difference as compared to a group of dogs without testicular neoplasia. In two thirds of the cases the concentration of oestradiol in the spermatic venous blood draining the neoplastic testes was clearly higher than in the normal dogs. The testosterone concentration in the spermatic venous blood from the tumour bearing testes was lower than in the spermatic venous blood of the contralateral partner testes in the same dogs, though not different from the spermatic venous concentration in the control dogs. There was no correlation between the presence or absence of signs of feminization and the peripheral or spermatic venous concentration of sex steroids. It is concluded that not only Sertoli cell tumours, but also seminomas can secrete increased amounts of oestrogens. This is possibly due to the presence of a larger than normal mass of tissue capable of converting testosterone, or its precursors, to oestradiol.

Download Full-text

STIMULATORY EFFECT OF PROSTAGLANDIN F2α ON THE PLASMA CONCENTRATION OF TESTOSTERONE IN BULLS

Journal of Endocrinology ◽

10.1677/joe.0.0660329 ◽

1975 ◽

Vol 66 (3) ◽

pp. 329-338 ◽

Cited By ~ 17

Author(s):

N. B. HAYNES ◽

H. D. HAFS ◽

R. J. WATERS ◽

J. G. MANNS ◽

A. RILEY

Keyword(s):

Plasma Concentration ◽

Intramuscular Injection ◽

Prostaglandin F2α ◽

Plasma Testosterone ◽

Testosterone Concentration ◽

Peripheral Plasma ◽

Prostaglandin F ◽

The Mean

SUMMARY The concentrations of peripheral plasma testosterone were measured by radioimmunoassay in samples collected from five bulls, each given i.m. injections of 0, 5, 15, 30 and 60 mg prostaglandin F2α (PGF2α). Synchronized peaks in testosterone concentration occurred with maximum values 1–2 h after treatment. These increases of testosterone persisted significantly longer than those observed to occur as natural episodic peaks during two 24 h periods in the same bulls. The mean peak testosterone concentration after PGF2α injection was related to the dose of PGF2α, values after 60 and 30 mg doses being significantly greater than after 15 mg. The response produced by a 5 mg dose was not significant. The results indicate that intramuscular injection of PGF2α acutely stimulates synthesis and release of testosterone in bulls.

Download Full-text

Plasma concentrations of testosterone and luteinizing hormone in rutting reindeer bulls (Rangifer tarandrus)

Canadian Journal of Zoology ◽

10.1139/z80-285 ◽

1980 ◽

Vol 58 (11) ◽

pp. 2081-2083 ◽

Cited By ~ 7

Author(s):

K.-A. Stokkan ◽

K. Hove ◽

W. R. Carr

Keyword(s):

Luteinizing Hormone ◽

Testosterone Level ◽

Plasma Concentrations ◽

Plasma Testosterone ◽

Plasma Samples ◽

Diurnal Pattern ◽

Testosterone Concentration ◽

Peripheral Plasma ◽

The Mean

Concentrations of plasma testosterone and luteinizing hormone (LH) were measured in peripheral plasma from semidomestic, rutting reindeer bulls. Although the concentrations of plasma testosterone were high and showed large variations, those of LH were low and only a few episodic bursts could be detected in hourly samples taken throughout a 48-h period. The mean testosterone concentration in three bulls differed significantly and ranked the animals according to their position in a fighting hierarchy. The mean concentrations of LH did not differ significantly. Plasma samples from one reindeer bull sampled every 20 min for periods of 3 h indicated that an increment in LH concentration preceded a peak in testosterone. No diurnal pattern in testosterone concentrations could be detected, but testosterone peaks seemed to appear about every 3–4 h. The present study thus demonstrates that a series of plasma samples throughout the day is necessary to determine a true "testosterone level" in the reindeer bull.

Download Full-text