Effect of stress administered during pregnancy on the development of fetal testes and their subsequent function in the adult rat

1985 ◽  
Vol 107 (2) ◽  
pp. 241-245 ◽  
Author(s):  
I. Pollard ◽  
S. L. Dyer
Keyword(s):  
Plasma Testosterone ◽  
Adult Males ◽  
Critical Periods ◽  
Short Term ◽  
Plasma Progesterone ◽  
Adult Rat ◽  
Stressed Group ◽  
Gonadotrophin Secretion ◽  
Basal Plasma ◽  
Circulating Levels

ABSTRACT When maternal stress, containing a large anxiety component, was administered during pregnancy there was a significant decrease in 3β-hydroxysteroid dehydrogenase (3β-HSD) activity in the fetal testis from days 16 to 20 of gestation, but not at birth nor in the first week after birth. However, persistent effects were found in adult males of 90 days of age. Basal testosterone concentrations in both plasma and testes and testicular 3β-HSD activity were significantly lower whilst basal plasma progesterone concentrations were significantly higher in the stressed group. When the stressed offspring were subjected to short-term stress (one session), their plasma testosterone concentration was significantly below that of the controls. It is suggested that suppressed gonadotrophin secretion during critical periods of development alters fetal testicular function, and that raised circulating levels of stress-induced hormones such as β-endorphin may be responsible for changes in gonadotrophin secretion. J. Endocr. (1985) 107, 241–245

PLASMA TESTOSTERONE IN KLINEFELTER'S SYNDROME: DIURNAL VARIATION AND RESPONSE TO ACTH AND DEXAMETHASONE

1975 ◽  
Vol 78 (3) ◽  
pp. 604-612 ◽  
Author(s):  
A. G. H. Smals ◽  
P. W. C. Kloppenborg ◽  
T. J. Benraad
Keyword(s):  
Plasma Testosterone ◽  
Klinefelter’S Syndrome ◽  
Klinefelter's Syndrome ◽  
Normal Range ◽  
Short Term ◽  
Plasma Testosterone Level ◽  
Testosterone Levels ◽  
Basal Plasma ◽  
Order Of Magnitude ◽  
The Mean

ABSTRACT The mean basal plasma testosterone level in 28 patients with chromatin positive Klinefelter's syndrome was significantly lower than in 58 healthy male controls. In 12 of the patients the hormone levels were in the normal range. In both the eugonadal males and the Klinefelter patients the plasma testosterone levels spontaneously decreased throughout the day, the relative decrease in both groups being of the same order of magnitude. Short term ACTH infusion and the administration of dexamethasone did not significantly influence the plasma testosterone concentration in the Klinefelter patients. These findings do not support the view that the adrenal cortex plays a major role in contributing to the circulating plasma testosterone levels in this syndrome.

PHOTOPERIODIC CONTROL OF GONADOTROPHIN SECRETION IN THE RAM: A DETAILED STUDY OF THE TEMPORAL CHANGES IN PLASMA LEVELS OF FOLLICLE-STIMULATING HORMONE, LUTEINIZING HORMONE AND TESTOSTERONE FOLLOWING AN ABRUPT SWITCH FROM LONG TO SHORT DAYS

1977 ◽  
Vol 74 (3) ◽  
pp. 355-367 ◽  
Author(s):  
G. A. LINCOLN ◽  
M. J. PEET
Keyword(s):  
Plasma Levels ◽  
Photoperiodic Response ◽  
Plasma Testosterone ◽  
Short Term ◽  
Artificial Lighting ◽  
Lighting Conditions ◽  
Gonadotrophin Secretion ◽  
Low Levels ◽  
Lh Rh ◽  
Short Days

SUMMARY Six adult Soay rams were housed under artificial lighting conditions of long days (16 h light: 8 h darkness) for 4 months and this caused the animals to lapse into a state of reproductive quiescence with low levels of gonadotrophins in the circulation and regressed testes secreting very low amounts of testosterone. The photoperiod was changed abruptly to short days (8 h light: 16 h darkness) to induce a resurgence of sexual activity, and a detailed study was made of the pituitary and testicular responses over the first 100 days. Plasma levels of LH and FSH first began to increase between days 6 and 12 of short days, and rose progressively until days 33–54 before declining again. Testicular growth of the rams began on days 19–26 and continued for most of the remaining period of study. Plasma testosterone levels rose in parallel with the growth of the testes, and were greatly increased by day 100 when gonadotrophin levels were reduced. At most stages there were short-term fluctuations in the plasma levels of FSH, LH and testosterone indicative of episodic secretion. Peaks in plasma levels of LH were especially conspicuous and from the changes in frequency and amplitude of these peaks it was possible to predict the way in which photoperiod influenced gonadotrophin secretion by its effect on hypothalamic LH-RH secretion. A slight 24 h rhythm in the plasma levels of all three hormones was observed, and the significance of this in relation to the photoperiodic response is discussed.

INFLUENCE OF METYRAPONE ON PLASMA CONCENTRATIONS OF TESTOSTERONE AND ANDROSTENEDIONE IN MAN

1971 ◽  
Vol 68 (3) ◽  
pp. 576-584 ◽  
Author(s):  
K. O. Nilsson ◽  
B. Hökfelt
Keyword(s):  
Body Weight ◽  
Male Patient ◽  
Gradual Increase ◽  
Plasma Concentrations ◽  
Plasma Testosterone ◽  
Testosterone Levels ◽  
Basal Plasma ◽  
Normal Males ◽  
A Minor ◽  
Secondary Hypogonadism

ABSTRACT Metyrapone was administered either orally, 750 mg every four h, in a total of six doses, or intravenously 30 mg per kg body weight as a four h infusion. In three males with normal endocrine functions, metyrapone given orally or intravenously induced a fall in plasma testosterone and an elevation of androstenedione within 2–8 h. When metyrapone was administered to a patient given dexamethasone to suppress endogenous ACTH production, the androstenedione levels did not alter whereas the testosterone levels showed a slight, transient decrease. In two normal females metyrapone administration was followed by a marked increase in plasma androstenedione whereas testosterone showed only a minor, gradual increase. In one male patient with Addison's disease the basal plasma testosterone was normal whereas the level of androstenedione was low. Following metyrapone intravenously, there was a slight suppression of plasma testosterone but no change in the androstenedione concentration. In one patient with primary hypogonadism, two with secondary hypogonadism and two with Klinefelter's syndrome the plasma testosterone was low under basal conditions and did not change following metyrapone. Basal plasma androstenedione was within the range for normal males and increased markedly following metyrapone in all the cases.

GONADAL HORMONES AND THE CONTROL OF OVULATION IN THE GUINEA-PIG

1972 ◽  
Vol 55 (3) ◽  
pp. 599-607 ◽  
Author(s):  
B. T. DONOVAN ◽  
A. N. LOCKHART
Keyword(s):  
Guinea Pig ◽  
Corpus Luteum ◽  
Acute Treatment ◽  
Gonadal Hormones ◽  
Time Of Day ◽  
Gonadal Steroids ◽  
Corpora Lutea ◽  
Plasma Progesterone ◽  
Gonadotrophin Secretion ◽  
Oestradiol Benzoate

SUMMARY The release of ovulating hormone after acute treatment with gonadal steroids, or corpus luteum removal on different days of the oestrous cycle, was studied in the guinea-pig. Injection of 25, 50 or 100 μg oestradiol or 2·5 mg progesterone on day 13 of the cycle had no effect upon gonadotrophin secretion as judged by follicular histology, but markedly altered the sizes of the corpora lutea of the previous ovulation. Treatment with oestradiol on day 14 did not elicit gonadotrophin secretion. However, administration of the same hormones to animals given 10 μg oestradiol benzoate 24 h earlier caused ovulation or follicular luteinization. Progesterone (2·5 mg) appeared least effective in stimulating gonadotrophin release; 25 μg oestradiol were more effective when given at 12.00 h than at 24.00 h but treatment with both hormones caused ovulation when given at either time of day. Luteal volumes were not affected. Removal of corpora lutea during the second half of the cycle advanced the time of expected ovulation to day 15 or earlier when the procedure was carried out on days 8 or 9, but not on days 10–13. It is concluded that 4–5 days must elapse between the fall in plasma progesterone level associated with corpus luteum regression and the release of ovulating hormone.

Short-Term Plasticity at Inhibitory Synapses in Rat Striatum and Its Effects on Striatal Output

2001 ◽  
Vol 85 (5) ◽  
pp. 2088-2099 ◽  
Author(s):  
John S. Fitzpatrick ◽  
Garnik Akopian ◽  
John P. Walsh
Keyword(s):  
Action Potentials ◽  
Brain Slices ◽  
Current Injection ◽  
Inhibitory Synapses ◽  
Rat Striatum ◽  
Short Term ◽  
Short Term Plasticity ◽  
Adult Rat ◽  
Glutamate Receptor Antagonists

Two forms of short-term plasticity at inhibitory synapses were investigated in adult rat striatal brain slices using intracellular recordings. Intrastriatal stimulation in the presence of the ionotropic glutamate receptor antagonists 6-cyano-7-nitroquinoxaline-2,3-dione (20 μM) andd,l-2-amino-5-phosphonovaleric acid (50 μM) produced an inhibitory postsynaptic potential (IPSP) that reversed polarity at −76 ± 1 (SE) mV and was sensitive to bicuculline (30 μM). The IPSP rectified at hyperpolarized membrane potentials due in part to activation of K+ channels. The IPSP exhibited two forms of short-term plasticity, paired-pulse depression (PPD) and synaptic augmentation. PPD lasted for several seconds and was greatest at interstimulus intervals (ISIs) of several hundred milliseconds, reducing the IPSP to 80 ± 2% of its control amplitude at an ISI of 200 ms. Augmentation of the IPSP, elicited by a conditioning train of 15 stimuli applied at 20 Hz, was 119 ± 1% of control when sampled 2 s after the conditioning train. Augmentation decayed with a time constant of 10 s. We tested if PPD and augmentation modify the ability of the IPSP to prevent the generation of action potentials. A train of action potentials triggered by a depolarizing current injection of constant amplitude could be interrupted by stimulation of an IPSP. If this IPSP was the second in a pair of IPSPs, it was less effective in blocking spikes due to PPD. By contrast, augmented IPSPs were more effective in blocking spikes. The same results were achieved when action potentials were triggered by a depolarizing current injection of varying amplitude, a manipulation that produces nearly identical spike times from trial to trial and approximates the in vivo behavior of these neurons. These results demonstrate that short-term plasticity of inhibition can modify the output of the striatum and thus may be an important component of information processing during behaviors that involve the striatum.

SHORT-TERM EFFECTS OF COPULATION, HUMAN CHORIONIC GONADOTROPHIN INJECTION AND NON-TACTILE ASSOCIATION WITH A FEMALE ON TESTOSTERONE LEVELS IN THE MALE RAT

1974 ◽  
Vol 60 (3) ◽  
pp. 429-439 ◽  
Author(s):  
K. PURVIS ◽  
N. B. HAYNES
Keyword(s):  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Physical Contact ◽  
Male Rats ◽  
Male Rat ◽  
Plasma Testosterone ◽  
Short Term ◽  
Testosterone Levels ◽  
Peripheral Plasma ◽  
First Contact

SUMMARY Peripheral plasma testosterone levels in the male rat were increased above control levels 5 min after the first intromission with an oestrous female, or 8–10 min after first contact with the female. The levels remained raised for at least 30 min if copulation was allowed to continue. Intravenous injection of human chorionic gonadotrophin resulted in an increased peripheral concentration of plasma testosterone after 10–15 min and an increase of testosterone content of the testis 5–10 min after injection, indicating that the rat testis has a potential to respond rapidly to gonadotrophin. The results suggested that if the testosterone surge during copulation was gonadotrophin-dependent, it was initiated before the first intromission. Indeed, plasma testosterone levels were raised in male rats 5 min after being placed in the proximity of oestrous females but not allowed physical contact.

Assessment of Protein Needs of Nigeria Adult Males Using Short-Term Nitrogen Balance Technique

2010 ◽  
Vol 9 (2) ◽  
pp. 128-133
Author(s):  
T. Atinmo ◽  
G. Elemo ◽  
C.M.F. Mbofung ◽  
T. Oguntona ◽  
O.L. Erukainure
Keyword(s):  
Nitrogen Balance ◽  
Adult Males ◽  
Short Term ◽  
Balance Technique

Thermogenic effect of thyroid hormones: interactions with epinephrine and insulin.

1990 ◽  
Vol 259 (3) ◽  
pp. E305
Author(s):  
V Piolino ◽  
K J Acheson ◽  
M J Müller ◽  
N Jeanprêtre ◽  
A G Burger ◽  
...  
Keyword(s):  
Energy Expenditure ◽  
Thyroid Hormones ◽  
Basal Insulin ◽  
Plasma Insulin ◽  
Resting Energy Expenditure ◽  
Fat Free Mass ◽  
Short Term ◽  
Epinephrine Infusion ◽  
Before And After ◽  
Basal Plasma

The interactions between thyroid hormones, epinephrine, and insulin in the regulation of energy expenditure were investigated in a group of healthy young men before and after thyroxine (T4) treatment (300 micrograms/day for 14 days) at basal plasma insulin concentrations and during hypoinsulinemia with and without epinephrine infusion (0.05 micrograms.kg fat-free mass-1.min-1). T4 treatment induced moderate hyperthyroidism and increased resting energy expenditure (RMR). The effect was more pronounced during short-term hypoinsulinemia, but hypoinsulinemia by itself did not influence RMR. Epinephrine infusion caused a significant increase in energy expenditure. The effect was most pronounced at hypoinsulinemia and with T4 treatment. Hypoinsulinemia and T4 treatment were not additive in their effects. We conclude that basal insulin concentrations mask some of the thermogenic effects of thyroid hormones and epinephrine. Thus insulin antagonism may suppress some of the thermogenic actions of thyroid hormones and epinephrine.

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