It has become increasingly clear that cytokines play an important role in modulating neuroendocrine regulation, especially in the secretion of corticotropin (ACTH) in the pituitary. Oncostatin M (OSM), a cytokine of IL-6 family has been reported to increase ACTH secretion and pro-opiomelanocortin (POMC) transcription in murine corticotroph pituitary tumor cells (AtT20 cells). The present study was undertaken to determine the effects of OSM on hormonal release in primary culture of rat pituitary cells. Growth hormone or prolactin release was not affected by OSM. OSM (1 nM) stimulated ACTH release (35.1% increase versus control, p>0.001) in dispersed pituitary cells of rat to a lesser extent than in AtT20 cells. Corticotropin releasing hormone (CRH) (10 nM) also induced a 2.3-fold increase of ACTH secretion (p>0.001), but co-treatment of OSM and CRH did not exhibit any synergistic effect on ACTH secretion. We conclude OSM has a stimulatory effect on ACTH secretion in normal rat pituitary cell cultures, and OSM acts mainly on corticotroph, supporting the potential role of OSM to modulate immune-endocrine regulation in the pituitary.
Animal ; Cells, Cultured ; Corticotropin/secretion* ; Cytokines/pharmacology ; Cytokines/metabolism* ; Inflammation Mediators/pharmacology ; Inflammation Mediators/metabolism* ; Male ; Peptides/pharmacology ; Peptides/metabolism* ; Pituitary Gland/metabolism* ; Pituitary Gland/drug effects ; Pituitary Gland/cytology ; Prolactin/secretion* ; Rats ; Rats, Inbred WF ; Somatotropin/secretion*

It has become increasingly clear that cytokines play an important role in modulating neuroendocrine regulation, especially in the secretion of corticotropin (ACTH) in the pituitary. Oncostatin M (OSM), a cytokine of IL-6 family has been reported to increase ACTH secretion and pro-opiomelanocortin (POMC) transcription in murine corticotroph pituitary tumor cells (AtT20 cells). The present study was undertaken to determine the effects of OSM on hormonal release in primary culture of rat pituitary cells. Growth hormone or prolactin release was not affected by OSM. OSM (1 nM) stimulated ACTH release (35.1% increase versus control, p>0.001) in dispersed pituitary cells of rat to a lesser extent than in AtT20 cells. Corticotropin releasing hormone (CRH) (10 nM) also induced a 2.3-fold increase of ACTH secretion (p>0.001), but co-treatment of OSM and CRH did not exhibit any synergistic effect on ACTH secretion. We conclude OSM has a stimulatory effect on ACTH secretion in normal rat pituitary cell cultures, and OSM acts mainly on corticotroph, supporting the potential role of OSM to modulate immune-endocrine regulation in the pituitary.
Animal ; Cells, Cultured ; Corticotropin/secretion* ; Cytokines/pharmacology ; Cytokines/metabolism* ; Inflammation Mediators/pharmacology ; Inflammation Mediators/metabolism* ; Male ; Peptides/pharmacology ; Peptides/metabolism* ; Pituitary Gland/metabolism* ; Pituitary Gland/drug effects ; Pituitary Gland/cytology ; Prolactin/secretion* ; Rats ; Rats, Inbred WF ; Somatotropin/secretion*

OBJECTIVETo investigate the influence of fructus schisandrae (FS) on the function of the pituitary-testis axis and carbohydrate metabolism in male rats undergoing experimental navigation and strenuous exercise.

METHODSThirty-four SD rats were randomly allocated into three groups, quiescent control (A), stress control (B) and FS (C). Those in Groups B and C received 10 days of Benford's high-intensity training, followed by 7 days of intragastric administration of normal saline and FS, respectively. Blood samples were immediately obtained at the end of the experiment for the measurement of the levels of serum testosterone (T), corticosterone (CORT), luteinizing hormone (LH) and blood glucose (Glu) by radioimmunoassay. The pituitary gland and testis tissues were also collected for the observation of their ultrastructures under the electron microscope.

RESULTSGroup A showed a significantly lower Glu level and a higher T level than B ([5.22 +/- 2.13] mmol/L versus [9.41 +/- 2.56] mmol/L, and [0.61 +/- 0.68] ng/ml versus [0.10 +/- 0.15] ng/ml, P < 0.01), but there was no significant difference in the CORT level between the two groups ([4.67 +/- 1.19] ng/ml versus [7.25 +/- 6.20] ng/ml, P > 0.05). Compared with Group B, both the Glu and CORT levels were remarkably decreased in Group C ([5.09 +/- 1.64] mmol/L and [3.55 +/- 3.52] ng/ml, P < 0.05 and P < 0.01), but the T level showed no significant change ([0.11 +/- 0.12] ng/ml, P > 0.05). And there were no significant differences in the serum LH level among the three groups (P > 0.05). Ultrastructural pathology showed a significant reduction of secretory granules in the pituitary cells in Group B as compared with A, and a markedly increased number of granules in the cytoplasm in Group C in comparison with B. Such changes as mitochondrial swelling, increase of electron density and decrease or disappearance of mitochondrial cristae were also found in the Leydig cells of Group B. No significant differences were observed in the testicular cells between Groups and C.

CONCLUSIONExperimental navigation and high-intensity training significantly suppress the function of the pituitary-testis axis in rats. Intragastric administration of fructus schisandrae can protect the pituitary-testis axis and reduce the blood Glu level in the stressed rats.

Animals ; Carbohydrate Metabolism ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Male ; Physical Conditioning, Animal ; Pituitary Gland ; drug effects ; metabolism ; Rats ; Rats, Sprague-Dawley ; Schisandra ; chemistry ; Testis ; drug effects ; metabolism

The LH and FSH responses to synthetic LH-RH and the prolactin response to synthetic T-RH were evaluated during different phases of the mentrual cycle in order to understand secretory capacity of the pituitary during the menstrual cycle. Eleven regularly menstruating women between 22 and 35 years of age with a usual cycle length of 27 to 31 days volunteered for this Study. Volunteers received an intra-venous injection of 100 microgram synthetic LH-RH and 200 microgram synthetic T-RH during the early and the late follicular phases and during the early and midluteal phases of the menstrual cycle. LH-RH induced a prompt increase in circulating LH, reaching the peak concentration at 30 minutes following LH-RH administration in all phases of the cycle studied. A change in responsiveness with greater and more sustained LH release from the early to the late follicular phases was observed. The response during the luteal phase was significantly greater than the responses in both the early and the late follicular phases. A concomitant but a much smaller FSH response was observed. T-RH elicited a prompt increase in circulating prolactin within 30 minutes and decreased gradually thereafter, reaching the baseline level by 2 hours after T-RH administration. Maximum concentration of prolactin was reached in 30 minutes following T-RH during all phases of the menstrual cycle. No variation in pituitary responsiveness to T-RH, however, was observed during different phases of the menstrual cycle. These data indicate that the sensitivity of the pituitary gonadotrophs to LH-RH varies during different phases of the menstrual cycle.
Adult ; Female ; Follicle Stimulating Hormone/secretion ; Gonadorelin/pharmacology* ; Human ; Luteinizing Hormone/secretion ; Menstruation* ; Pituitary Gland/drug effects* ; Protirelin/pharmacology*

AIMTo study the effects of Cu2+ on growth hormone (GH) secretion of pig pituitary cells in vivo.

METHODSGland pituitary cells of 32-35 days old pigs were incubated for 48 h in presence of 10% fetal calf serum in DMEM. Cells were treated for 36 h with various concentrations of Cu2+ (0 mg/L, 0.025 mg/L, 0.1 mg/L, 0.4 mg/L, 1.6 mg/L) in serum-free DMEM. Culture medium was collected in 12 h, 24 h, 36 h thereafter for GH measurement and the radioimmunoassay kits were provided by Linco.

RESULTSThe GH concentration was higher in treatments of 0.025 mg/L, 0.1 mg/L, 0.4 mg/L than that of 0 mg/L when the cells were treated with Cu2+ for 24 h, and it was significantly different (P < 0.05) between treatment 0.1 mg/L and treatment 0 mg/L.

CONCLUSIONIt was concluded that the presence of Cu2+ stimulated pig pituitary cells to secret GH in vivo.

Animals ; Cells, Cultured ; Copper ; pharmacology ; Culture Media ; Growth Hormone ; secretion ; Pituitary Gland ; cytology ; drug effects ; metabolism ; Swine

Animals ; Cells, Cultured ; Cyclic AMP ; metabolism ; Pituitary Gland, Anterior ; cytology ; drug effects ; metabolism ; Rats ; Substance P ; pharmacology

OBJECTIVETo study the effects of C. versicolor petroleum ether extracts (CVPE) on the adenohypophysis androgen receptor level in mature castrated male rats.

METHODAll the rats in experiment were anesthetized for bilateral testicular and epididymis removal under sterile condition. The rats were randomized into four groups on the 14 th day after operation. The first group was intragastric physiological saline for castratered control group. The second group was intragastric CVPE 2 g x kg(-1) for low-dose group. The third group was high-dose group by giving CVPE 4 g x kg(-1). The fourth group was injected hypodermic testosterone propionate for positive-effect drug treatment group. The drug was given orally to animals one time a day successively for 21 days. The androgen receptor (AR) in adenohypophysis of mature castrated male rats was determined by the immunohistochemistry method and the level of serum testosterone (T) were determined by the radio-immunoassay after ig CVPE for 21 days.

RESULTThe immunohistochemistry results showed that positive cell numbers of androgen receptor in positive control and each CVPE groups were more than those in the castrated control group. The serum T level was increased greatly in mature castrated male rats treated with CVPE compared with the control group (P < 0.05, P < 0.01).

CONCLUSIONThe results show that CVPE can increase the adenohypophysis androgen receptor and serum T level in mature castrated male rats. It is indicated that CVPE has the effects on the hypophysis function.

Animals ; Lizards ; Male ; Materia Medica ; isolation & purification ; pharmacology ; Orchiectomy ; Pituitary Gland, Anterior ; drug effects ; metabolism ; Random Allocation ; Rats ; Rats, Wistar ; Receptors, Androgen ; metabolism ; Testosterone ; blood

OBJECTIVETo investigate the effects of purine nucleotide on the expressions of follicle-stimulating hormone (FSH) and luteotrophic hormone (LH) and the ultrastructures of the distal somatotrophic and gonadotrophic cells in the pituitary gland of heroin-addicted and -withdrawal rats.

METHODSNinety-two male Wistar rats were randomly divided into a control group (ip saline for 14 d), a nucleotide group (ip AMP and GMP for 10 d), a heroin group (ip heroin for 10 d), a heroin + nucleotide group (ip AMP and GMP + heroin for 10 d), a 3 d withdrawal group (ip heroin for 10 d and killed at 14 d), a 9 d withdrawal group (ip heroin for 10 d and killed at 20 d), a 3 d nucleotide group (ip nucleotide for 3 d after 10 d heroin administration and killed at 14 d), and a 9 d nucleotide group (ip nucleotide for 9 d after 10 d heroin administration and killed at 20 d). Changes in the mRNA expressions of FSH and LH in the pituitary gland of the rats were analyzed by semi-quantitative RT-PCR, and alterations in the ultrastructures of the distal somatotrophic and gonadotrophic cells were observed under the microscope.

RESULTSThe expression of FSH mRNA was significantly increased in the nucleotide, heroin + nucleotide, 3 d nucleotide and 9 d nucleotide groups (0.099 +/- 0.018, 0.177 +/- 0.046, 0.151 +/- 0.030 and 0.184 +/- 0.028) as compared with the control group (0.045 +/- 0.009) (P < 0.01); and so was that of LH mRNA in the heroin + nucleotide, 3 d nucleotide and 9 d nucleotide groups (0.950 +/- 0.169, 0.990 +/- 0.171 and 0.960 +/- 0.147) in comparison with the control group (0.700 +/- 0.099) (P < 0.01). In the heroin group, the nuclei of the distal somatotrophic and gonadotrophic cells exhibited morphological abnormality, unclear membrane, slightly pyknotic matrix, marginal and agglutinated heterochromatin, dilated rough endoplasmic reticula, swollen mitochondria, broken and vacuolated cristae in the cytoplasm, obviously decreased number of secretory granules, and myelin bodies in some cells. However, the heroin + nucleotide group showed no significant changes in the ultrastructures of somatotrophic and gonadotrophic cells compared with the control group.

CONCLUSIONShort-term use of heroin does not obviously affect the expressions of FSH and LH mRNA in the pituitary gland of rats, while heroin + nucleotide, or nucleotide following heroin withdrawal can enhance their expressions significantly. Heroin damages the ultrastructures of the distal somatotrophic and gonadotrophic cells in the pituitary gland of male rats, and purine nucleotide can diminish or inhibit this damage.

Animals ; Follicle Stimulating Hormone ; genetics ; metabolism ; Gene Expression ; drug effects ; Heroin ; adverse effects ; Heroin Dependence ; genetics ; metabolism ; Luteinizing Hormone ; genetics ; metabolism ; Male ; Pituitary Gland ; drug effects ; metabolism ; ultrastructure ; Purine Nucleotides ; pharmacology ; Rats ; Rats, Wistar ; Substance Withdrawal Syndrome ; genetics ; metabolism

OBJECTIVETo study the effects of salidroside on the function and ultramicro-pathological change of the hypothalamic-pituitary-gonadal (HPG) axis of male rats in experimental navigation and intensive exercise.

METHODSSix-week SD rats were randomized into 3 groups: non-stress control (NC, n = 10), training control (TC, n = 12) and salidroside treatment (ST, n = 12) group. Blood samples were collected from the NC rats that did not receive any stimulus after a 7-day intragastric administration of saline. The TC rats underwent a 10-day running training with increasing load on the treadmill followed by a 7-day intragastric administration of saline. The ST rats were subjected to the same process of running training as the TC group and received intragastric administration of salidroside. Then blood samples were immediately obtained and the levels of testosterone (T), corticosterone (CORT), adrenocorticotropic hormone (ACTH), luteinizing hormone (LH) and gonadotropin-releasing hormone (GnRH) measured by radioimmunoassay. The testis histopathology was observed by HE staining, and the ultrastructural changes of the pituitaries and testes investigated by electron microscopy.

RESULTSThe serum T level was significantly lower in the TC than in the NC group, but showed no significant difference between the ST and NC groups. HE staining revealed no significant difference in testis histopathology among the 3 groups. Ultramicro-pathology showed that the secretory granules of the pituitary cells were significantly reduced in the TC rats compared with the NC ones; the number of the granules significantly increased in the ST group compared with the TC rats; and mitochondrial swelling, increase of electron density and decrease/disappearance of mitochondrial cristae were observed in the Leydig cells of the TC rats. But no significant differences were found in the testicular cells between the ST and NC groups.

CONCLUSIONNegative psychological stress and intensive exercise can significantly suppress the function of the HPG axis in rats. Salidroside therapy has protective effect on the HPG axis.

Animals ; Glucosides ; pharmacology ; therapeutic use ; Hypothalamo-Hypophyseal System ; drug effects ; pathology ; Male ; Phenols ; pharmacology ; therapeutic use ; Physical Conditioning, Animal ; Pituitary Gland ; drug effects ; pathology ; Rats ; Rats, Sprague-Dawley ; Rhodiola ; chemistry ; Stress, Psychological

BACKGROUNDDelayed puberty can result either from constitutional delay of growth and puberty (CDP) or idiopathic hypogonadotropic hypogonadism (IHH). Gonadotropin-releasing hormone (GnRH) stimulation test has been generally accepted as a current method for diagnosing delayed puberty. The objective of this research was to assess the cut-off values and the efficacy of GnRH stimulation test in the diagnosis of delayed puberty in both males and females.

METHODSA study of 91 IHH, 27 CDP patients, 6 prepubertal children, and 20 pubertal adults was undertaken. Blood samples were obtained at 0, 30, 60, and 120 min after GnRH administration and the levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured. For each parameter, the sensitivities and specificities were estimated, and the receiver operating characteristic (ROC) curves were constructed.

RESULTSThe ROC curves indicated that a serum basal LH <0.6 IU/L or peak LH <9.74 IU/L resulted in moderate sensitivity (73.8% or 80.0%) and specificity (90.9% or 86.4%) in the diagnosis of HH in males. Serum basal LH <0.85 IU/L or basal FSH <2.43 IU/L resulted in moderate sensitivity (80.0% or 100.0%) and specificity (75.0% or 50.0%) in the diagnosis of HH in females.

CONCLUSIONSOur data suggest that isolated use of the gonadorelin stimulation test is almost sufficient to discriminate between HH and CDP in males, but unnecessary in females. The most useful predictor is serum basal or peak LH to differentiate these two disorders in males, but serum basal LH or FSH in females.

Adolescent ; Female ; Follicle Stimulating Hormone ; blood ; Gonadotropin-Releasing Hormone ; pharmacology ; Gonadotropins ; deficiency ; Humans ; Hypogonadism ; blood ; diagnosis ; Hypothalamus ; drug effects ; Luteinizing Hormone ; blood ; Male ; Pituitary Gland ; drug effects ; Puberty, Delayed ; blood ; diagnosis ; Sensitivity and Specificity