Cerebrospinal fluid and blood concentrations of luteinizing hormone, follicle stimulating hormone and prolactin following castration of adult male rats

1992 ◽  
Vol 127 (1) ◽  
pp. 58-65 ◽  
Author(s):  
Nafisa Balasinor ◽  
Manjit K Gill-Sharma ◽  
Priyanka Parte ◽  
HS Juneja
Keyword(s):  
Cerebrospinal Fluid ◽  
Adult Male ◽  
Systemic Circulation ◽  
Male Rats ◽  
Sham Operation ◽  
Turnover Rates ◽  
Blood Concentrations ◽  
Serum Lh ◽  
Norepinephrine Turnover ◽  
Hypothalamic Dopamine

Comparative levels of LH, FSH and PRL in the serum and cerebrospinal fluid (CSF) of adult male rats were studied at different periods following castration. Intact and sham-operated animals served as controls. Blood and CSF were collected at 1, 3, 7, 14, 21, 28, 35 and 46 days following castration. The CSF was collected via cisterna-magna puncture, while the blood was collected from abdominal aorta. Serum gonadotropins increased progressively beginning day 1 post-castration to reach maximum by day 35 or 46 post-castration. Sham operation and castration did not affect mean CSF, LH and FSH levels compared to intact controls. Analysis of the temporal pattern of serum and CSF gonadotropin levels following castration revealed significant positive correlation between CSF and serum LH (r=0.58) and FSH (r=0.64) levels respectively. The data suggest that CSF gonadotropins may be derived from systemic circulation. Serum PRL levels were not affected by castration, but CSF PRL levels were significantly reduced at days 28, 35 and 46 post-castration compared to intact controls. CSF PRL levels showed negative correlation with serum LH and FSH levels but failed to show a correlation with serum PRL levels. Hypothalamic norepinephrine turnover rate increased at days 28, 35 and 46 post-castration. Hypothalamic dopamine contents and turnover rates were reduced at days 21 and 28 post-castration. It is suggested that CSF PRL may have a role in the regulation of serum gonadotropins.

Mechanism delineating differential effect of an antiestrogen, tamoxifen, on the serum LH and FSH in adult male rats

2006 ◽  
Vol 29 (6) ◽  
pp. 485-496 ◽  
Author(s):  
N. Balasinor ◽  
P. Parte ◽  
M. K. Gill-Sharma ◽  
J. Kini ◽  
H. S. Juneja
Keyword(s):  
Adult Male ◽  
Differential Effect ◽  
Male Rats ◽  
Serum Lh

GONADOTROPHIN SUPPRESSION BY STEROIDS IN NORMAL, ADULT MALE RATS

1977 ◽  
Vol 84 (4) ◽  
pp. 842-849 ◽  
Author(s):  
H. L. Verjans ◽  
K. B. Eik-Nes
Keyword(s):  
Body Weight ◽  
High Activity ◽  
Adult Male ◽  
Subcutaneous Administration ◽  
Serum Levels ◽  
Steroid Treatment ◽  
Male Rats ◽  
Normal Adult ◽  
Serum Lh ◽  
Testosterone Metabolites

ABSTRACT Effects of subcutaneous administration of various doses of different steroids on serum levels of LH and FSH in normal, adult male rats were investigated. Each steroid was injected daily during 7 days in doses of 50, 25, 12.5 or 6.25 μg per 100 g body weight. Ring A 5α-reduced testosterone metabolites exerted high activity in suppressing serum LH and FSH levels. 5α-Androstane-3β,17β-diol had in the doses tested, however, no such effects on serum gonadotrophins. Serum LH concentrations in normal rats appeared more sensitive to steroid treatment than serum FSH concentrations.

The contribution of corticosterone and testosterone to the suppression of serum LH in hyperprolactinaemic adult male rats with pituitary transplants

1987 ◽  
Vol 113 (1) ◽  
pp. 111-116 ◽  
Author(s):  
R. F. A. Weber ◽  
M. P. Ooms ◽  
J. T. M. Vreeburg
Keyword(s):  
Adult Male ◽  
Serum Testosterone ◽  
Serum Levels ◽  
Male Rats ◽  
Male Rat ◽  
Serum Concentrations ◽  
Testosterone Secretion ◽  
Accessory Sex Glands ◽  
Serum Lh ◽  
Stimulation Of

ABSTRACT The effects of hyperprolactinaemia on serum levels of LH were investigated in adult male rats of the R × U strain. Hyperprolactinaemia was induced by three pituitary grafts under the kidney capsule, transplanted on day 0 of each experiment. Special attention was paid to the contribution of prolactin-stimulated testes, adrenals and corticosterone. In experiment 1, hyperprolactinaemia significantly reduced the serum concentrations of LH in intact rats. In spite of a significant increase in the serum levels of corticosterone, serum testosterone was not significantly affected by hyperprolactinaemia. The weights of both the adrenals and accessory sex glands were significantly increased at autopsy. In experiment 2, treatment with 10 mg corticosterone s.c. daily from day 14 to day 28 after pituitary grafting significantly reduced serum levels of both LH and testosterone. The suppression of testosterone in the hyperprolactinaemic corticosterone-treated animals was significantly less than in the corticosterone-treated control animals. The weights of the accessory sex glands were significantly increased in the hyperprolactinaemic animals. In experiment 3, rats were adrenalectomized and half of them were substituted with corticosterone. Serum testosterone levels significantly increased in both hyperprolactinaemic adrenalectomized rats and in adrenalectomized corticosterone-treated animals without any significant effect on serum LH. Again the weights of the accessory sex glands were significantly increased in the hyperprolactinaemic animals. In experiment 4, rats were adrenalectomized, gonadectomized and corticosterone treated on day 0 and then implanted with a 2, 1·5 or 1 cm silicone elastomer capsule containing testosterone. On day 28 after pituitary grafting, LH levels were significantly suppressed in animals with a 2 or 1·5 cm testosterone implant. The weights of the accessory sex glands were not increased in the hyperprolactinaemic animals. These results show that in the male rat the inhibitory effects of hyperprolactinaemia on serum LH levels may be due to (1) increased sensitivity of the hypothalamic-pituitary axis to the negative feedback action of testosterone by prolactin and by the prolactin-stimulated corticosterone secretion and (2) stimulation of testicular testosterone secretion by prolactin, which can also explain the increased weights of the accessory sex glands. Even in the presence of high serum concentrations of corticosterone, stimulation of testicular testosterone secretion by prolactin was observed. J. Endocr. (1987) 113,111–116

Cardiac and splenic norepinephrine turnover during septic peritonitis

1986 ◽  
Vol 250 (5) ◽  
pp. R892-R897 ◽  
Author(s):  
S. B. Jones ◽  
M. F. Kovarik ◽  
F. D. Romano
Keyword(s):  
Septic Shock ◽  
Plasma Glucose ◽  
Cardiac Tissue ◽  
Cecal Ligation ◽  
Male Rats ◽  
Turnover Rates ◽  
Spleen Tissue ◽  
Glucose Levels ◽  
Norepinephrine Turnover ◽  
Septic Peritonitis

Postganglionic sympathetic activity was assessed in heart and spleen tissue in conscious rats under conditions of developing septic shock by quantitating norepinephrine (NE) turnover. Fasted male rats were subjected to cecal ligation and puncture and allowed to recover for 12-14 h. NE turnovers were measured by following the rate of [3H]NE decay, and measurements were made between 12 and 24 h after surgery. Plasma glucose and lactate were determined at times throughout the turnover protocol. NE turnover in cardiac tissue of septic animals was increased (0.134 micrograms X g-1 X h-1) in comparison with both surgical sham (0.052 micrograms X g-1 X h-1) and unoperated controls (0.051 micrograms X g-1 X h-1). NE turnover rates were also elevated in spleen tissue of septic rats (0.152 micrograms X g-1 X h-1) in comparison with both surgical sham (0.094 micrograms X g-1 X h-1) and unoperated controls (0.087 micrograms X g-1 X h-1). Plasma glucose levels suggest that septic rats are in the hyperglycemic phase of sepsis. These experiments support the concept of increased peripheral sympathetic outflow during the development of septic shock that would support hypermetabolic and subsequent hyperdynamic alterations which are well-recognized characteristics of the early stages of sepsis leading to septic shock.

SEXUAL DIFFERENTIATION IN THE PHASE OF THE CIRCADIAN RHYTHM OF [35S]METHIONINE INCORPORATION INTO CEREBRAL PROTEINS, AND OF SERUM GONADOTROPHIN LEVELS

1974 ◽  
Vol 62 (2) ◽  
pp. 257-265 ◽  
Author(s):  
M. B. ter HAAR ◽  
P. C. B. MacKINNON ◽  
M. G. BULMER
Keyword(s):  
Circadian Rhythm ◽  
Circadian Rhythms ◽  
Adult Male ◽  
Anterior Pituitary ◽  
Male Rats ◽  
Normal Adult ◽  
Adult Males ◽  
Serum Luteinizing Hormone ◽  
Serum Lh ◽  
The Brain

SUMMARY The incorporation of [35S]methionine into protein in various regions of the brain and in the anterior pituitary, and serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels were measured at 6 h intervals throughout a 24 h period in the following groups of Wistar rats: (1) normal adult males and females; (2) adult genetic males or females which had been respectively 'feminized' or 'masculinized' by androgen deprivation or administration in neonatal life. Similar measurements were made at 12 h intervals in adult male rats which had been castrated at 7 or 15 days of age. Serum LH levels showed a circadian rhythmicity in normal adult animals of both sexes, with peak levels in the male occurring 6 h earlier than those in the female. There was no statistically significant circadian rhythm in FSH levels in any group of animals. In all groups of castrated animals LH and FSH levels were raised but no circadian rhythms were observed. Incorporation of [35S]methionine into protein in all cerebral areas showed circadian rhythms, the peak values of which, in the adult males, were almost 8 h (120°) out of phase with those of the adult females. In the 'feminized' genetic males or 'masculinized' genetic females the rhythmic phase was reversed to that of the opposite genetic sex. Animals castrated at 7 days or 15 days of age did not appear to show a rhythm. A 12 h rhythm of incorporation was apparent in the anterior pituitary of the normal adult male and the adult 'masculinized' female; no significant rhythm was seen in the normal adult female and the 'feminized' male. It is suggested that a 'female type' rhythm of incorporation in the brain may be associated with the maintenance of oestrous cycles.

Reproductive toxicity of DDT in adult male rats

2001 ◽  
Vol 20 (8) ◽  
pp. 393-397 ◽  
Author(s):  
K Ben Rhouma ◽  
O Tébourbi ◽  
R Krichah ◽  
M Sakly
Keyword(s):  
Adult Male ◽  
Pesticide Exposure ◽  
Reproductive Toxicity ◽  
Male Rats ◽  
Male Rat ◽  
Seminiferous Tubules ◽  
Serum Lh ◽  
Testicular Weight ◽  
Hypothalamic Pituitary Axis ◽  
Dose Dependent

The reproductive toxicity of DDT was investigated in adult male rats exposed to 50 and 100 mg/kg body weight (b.wt) day 1 for 10 successive days. Compared with control animals, administration of DDT led to a dose-dependent reduction of testicular weight and the number as well as the percentage of motile spermatozoa in the epididymis. Testicular histological observationsrevealed alsoamarkedloss of gametes in the lumen of seminiferous tubules. In DDT treated rats, the seminal vesicles weights dropped significantly, resulting from a decrease of testosterone production by testes, whereas serum LH and FSH increased after pesticide exposure. This increase of gonadotrophin levels may be related to an impairment of the negative feedback exerted by the steroid on the hypothalamic–pituitary axis. It is concluded that DDT induced adverse effects on male rat fertility by acting directly on the testes and altering the neuroendocrinefunction.

SERUM LH AND FSH LEVELS FOLLOWING INTRAVENOUS INJECTION OF A GONADOTROPHIN RELEASING PRINCIPLE IN NORMAL AND GONADECTOMIZED ADULT MALE RATS TREATED WITH OESTRADIOL-17β OR 5α-DIHYDROTESTOSTERONE

1976 ◽  
Vol 83 (3) ◽  
pp. 493-505 ◽  
Author(s):  
H. L. Verjans ◽  
K. B. Eik-Nes
Keyword(s):  
Intravenous Injection ◽  
Adult Male ◽  
Response Pattern ◽  
Sesame Oil ◽  
Male Rats ◽  
Intact Control ◽  
Serum Lh ◽  
Hypothalamic Pituitary Axis ◽  
Pre Treatment ◽  
Higher Doses

ABSTRACT Effect of intravenous administration of a synthetic gonadotrophin releasing factor (GnRF) on circulating LH and FSH concentrations was investigated in normal and gonadectomized, adult male rats injected subcutaneously each day during seven days with various doses of oestradiol-17β or 5α-dihydrotestosterone in sesame oil. Higher increase in serum LH and FSH levels subsequent to intravenously administered GnRF was observed in castrated control animals than in intact control animals, though this increment was not of significant nature for serum FSH. Pre-treatment of normal and gonadectomized rats with oestradiol-17β resulted in an augmented response of serum LH and FSH concentrations to GnRF iv. Pre-treatment of normal and gonadectomized rats with 5α-dihydrotestosterone diminished serum LH and FSH response following administration of the same amount of GnRF. For these steroids to affect the response pattern of serum LH and FSH to GnRF iv, higher doses were required in normal than in gonadectomized animals. The data indicate that oestrogen and androgen may act at different sites in the male hypothalamic-pituitary axis with respect to regulation of pituitary gonadotrophins.

TESTOSTERONE AND OESTRADIOL SUPPRESSION OF LH AND FSH IN ADULT MALE RATS: DURATION OF CASTRATION, DURATION OF TREATMENT AND COMBINED TREATMENT

1973 ◽  
Vol 73 (1) ◽  
pp. 11-21 ◽  
Author(s):  
R. S. Swerdloff ◽  
P. C. Walsh
Keyword(s):  
Adult Male ◽  
Testosterone Propionate ◽  
Combined Treatment ◽  
Male Rats ◽  
Low Doses ◽  
Duration Of Treatment ◽  
Serum Lh ◽  
Oestradiol Benzoate ◽  
Hypothalamic Pituitary Axis ◽  
Androgen Effect

ABSTRACT The effects of androgens and oestrogens on serum LH and FSH in castrated rats were evaluated with regard to the modifying influences of duration of castration, duration of treatment and combined oestrogen-androgen effect. Serum LH was not greatly influenced by these variables. In contrast, serum FSH was shown to be more resistant to suppression by both steroids after at least five days of castration, requiring a longer duration of treatment to be suppressed to intact levels. Combined treatment of submaximally suppressive doses of testosterone propionate and oestradiol benzoate resulted in no additive effect on lowering serum FSH. Low doses of both androgens and oestrogens resulted in elevated levels of serum LH and FSH, suggesting that the adult male hypothalamic-pituitary axis may be responsive to positive feedback. In all studies, testosterone preferentially suppressed serum LH as compared to serum FSH. In contrast, oestradiol administration produced parallel inhibition of both LH and FSH. It is emphasized that neither oestrogen nor androgen alone, nor in combination, resulted in preferential inhibition of serum FSH over LH.

scholarly journals Focal CO2 dialysis in raphe obscurus does not stimulate ventilation but enhances the response to focal CO2 dialysis in the retrotrapezoid nucleus

2008 ◽  
Vol 105 (1) ◽  
pp. 83-90 ◽  
Author(s):  
Mirela Barros Dias ◽  
Aihua Li ◽  
Eugene Nattie
Keyword(s):  
Cerebrospinal Fluid ◽  
Tidal Volume ◽  
Adult Male ◽  
Male Rats ◽  
Whole Body ◽  
Breathing Frequency ◽  
Retrotrapezoid Nucleus ◽  
Artificial Cerebrospinal Fluid ◽  
Simultaneous Inhibition ◽  
Central Chemoreception

Simultaneous inhibition of the retrotrapezoid nucleus (RTN) and raphe obscurus (ROb) decreased the systemic CO2 response by 51%, an effect greater than inhibition of RTN (−24%) or ROb (0%) alone, suggesting that ROb modulates chemoreception by interaction with the RTN ( 19 ). We investigated this interaction further by simultaneous dialysis of artificial cerebrospinal fluid equilibrated with 25% CO2 in two probes located in or adjacent to the RTN and ROb in conscious adult male rats. Ventilation was measured in a whole body plethysmograph at 30°C. There were four groups ( n = 5): 1) probes correctly placed in both RTN and ROb (RTN-ROb); 2) one probe correctly placed in RTN and one incorrectly placed in areas adjacent to ROb (RTN-peri-ROb); 3) one probe correctly placed in ROb and one probe incorrectly placed in areas adjacent to RTN (peri-RTN-ROb); and 4) neither probe correctly placed (peri-RTN-peri-ROb). Focal simultaneous acidification of RTN-ROb significantly increased ventilation (V̇e) up to 22% compared with baseline, with significant increases in both breathing frequency and tidal volume. Focal acidification of RTN-peri-ROb increased V̇e significantly by up to 15% compared with baseline. Focal acidification of ROb and peri-RTN had no significant effect. The simultaneous acidification of regions just outside the RTN and ROb actually decreased V̇e by up to 11%. These results support a modulatory role for the ROb with respect to central chemoreception at the RTN.

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