Browsing by Author "Roth, C."

To address whether gonadotropin-releasing hormone (GnRH) regulates its own expression and the expression of its receptor in the hypothalamus and ovary, we treated five groups of prepubertal/peripubertal female rats from postnatal days 25-36 with either the GnRH agonist triptorelin (TRIP) or the GnRH antagonist cetrorelix (CET), each 10 or 100 mug/day, or a placebo. We compared their effects regarding pubertal development, serum gonadotropins and the expression of GnRH and GnRH-receptor in the hypothalamus, pituitary, ovary and uterus. Onset of puberty was determined by vaginal opening, and expression levels of GnRH and GnRH-receptor were determined using either quantitative real-time PCR or competitive RT-PCR. Onset of puberty was retarded by both analogs but CET (100 mug/day) inhibited while TRIP (10 and 100 mug/day) stimulated serum gonadotropins (P <0.05). The expression of GnRH in the preoptic area did not show significant differences among the treatment groups but ovarian GnRH mRNA levels were significantly stimulated by CET (100 mug/day). GnRH mRNA could not be detected in the uterus by either real-rime PCR or competetive RT-PCR. The GnRH-receptor expression ill the hypothalamus (preoptic area and medio-basal hypothalamus) did not vary among any of the groups, whereas in the pituitary GnRH-receptor mRNA levels were stimulated by TRIP (10 mug/day) but inhibited by CET (100 mug/day). In contrast, in the ovary GnRH-receptor mRNA levels were inhibited by both TRIP (100 mug/day) and CET (100 mug/day). Interestingly, the GnRH-receptor was even expressed in the uterus where it was strongly stimulated by both CET and TRIP in a dose-related manner. This shows that in addition to their different pituitary effects, the GnRH analogs cetrorelix and triptorelin exert different actions at the hypothalamic, ovarian and uterine level. This study also demonstrates an organ-specific regulation of GnRH and GnRH-receptor gene expression which is likely part of a local autoregulatory system. We conclude that the ovarian and uterine effects of GnRH analogs must be considered in addition to their known pituitary effects when deciding which GnRH analog is most suitable for treating precocious puberty.

Little is known about the association between the rate of cisplatin administration and the severity of cisplatin-induced renal damage in children. The purpose of this study was to compare severity and reversibility of renal damage in children after continuous and repetitive bolus administration of cisplatin and to correlate these data with pharmacokinetic parameters. Study subjects included six children (ten courses) receiving cisplatin as 1-h bolus infusions on three consecutive days (3x40 mg/m(2)) and four children (eight courses) receiving 72-h continuous infusions (120 mg/m(2)). In all courses, signs of glomerular and tubular damage were seen,as evidenced by elevated urinary excretion of alpha (1)-microglobulin, albumin and N-acetyl-beta -D-glucosa-minidase and decreased glomerular filtration rate (GFR). Comparing the two infusion regimens, the 1-h bolus administration of cisplatin was followed by significantly higher peak free platinum concentrations in plasma and urine (P <0.001), resulting in lower nadirs: of the GFR (P <0.005). Correlations were found between both peak free platinum concentrations in plasma and urine and maxima of urinary albumin and N-acetyl-beta -D-glucosaminidase excretion. Within 12 months after completion of cisplatin therapy, children in the 1-h bolus group had recovered only partially from subclinical nephrotoxicity, with five out of six showing pathological proteinuria. The results provide clear evidence that long-term ciplatin infusions are less nephrotoxic than repetitive bolus infusions.

GnRH agonists are the established treatment of precocious puberty caused by premature stimulation of gonadotropin secretion. It has been reported that after an initial stimulation ("flare-up") they reduce LH secretion by desensitization of pituitary GnRH receptors. Little has been published about the use of GnRH antagonists such as cetrorelix to control the onset of puberty and whether they are potentially advantageous compared with GnRH agonists. We conducted two multigroup experiments (12 and 10 d, respectively) treating prepubertal/peripubertal female rats with either the GnRH agonist triptorelin or buserelin and compared them with rats treated with the GnRH antagonist cetrorelix and controls to assess the effects on pubertal progress and serum hormones. In the second experiment, the effects of buserelin and cetrorelix on gene expression of the GnRH receptor, LH-beta, FSH-beta, and the alpha subunit genes in the pituitary were also investigated. Cetrorelix, triptorelin, and buserelin retarded the onset of puberty as determined by delayed vaginal opening, lower ovarian weights, and lower serum estradiol levels. However, although LH and FSH levels were stimulated by both agonists, they were inhibited by cetrorelix. In the cetrorelix versus buserelin experiment, pituitary gene expression of the GnRH receptor and LH-beta subunit were significantly lower in cetrorelix treated rats compared with controls whereas buserelin had little effect. Expression of FSH-beta and alpha subunit were stimulated by buserelin but not by cetrorelix. Even though all three of these GnRH analogues inhibited gonadal development and delayed the onset of puberty, the GnRH agonists had stimulating and inhibiting effects on the pituitary-gonadal axis whereas cetrorelix exerted only inhibiting effects. We conclude from this female rat model that cetrorelix may offer advantages for a more controlled medical treatment of precocious puberty compared with GnRH agonist treatment.

Objective In girls with congenital adrenal hyperplasia (CAH), genital ambiguity usually leads to a rapid neonatal diagnosis. Rarely, CAH causes complete virilization and mate sex assignment with a delayed diagnosis. After being confronted with very specific problems in two of such patients, we collected data of patients with CAH and complete virilization in a nationwide study to delineate specific problems of these rare patients in order to improve their management. Design and Patients Through the German Working Group of Paediatric Endocrinology (Arbeitsgemeinschaft Padiatrische Endokrinologie, APE), questionnaires were sent to all members caring for patients with CAH and complete virilization in their endocrine clinics. Data from 16 patients from 10 paediatric endocrine centres were assessed by questionnaire. Results The following problems have been encountered. (1) Sex assignment/gender identity: initially all patients had a male sex assignment. Six patients were diagnosed during the first month of life. Five were reassigned to female sex immediately, one at the age of 19 months. Except in one girl demonstrating some tomboyish behaviour, gender role behaviour in these patients did not differ from unaffected girls. Ten patients were diagnosed late at 3.4-7 years of age. In seven patients with a late diagnosis, male sex assignment was maintained; one of them expressed some concerns about living as a male. In three patients late sex reversal was performed, gender identity is very poor in one and new sex assignment is currently under consideration. (2) Surgery: irrespective of the sex assigned, all patients had between one and three surgical procedures, including clitoris reduction and (repeated) vaginoplasties in patients with female sex assignment. Hysterectomy and ovarectomy were performed in patients with male sex assignment. (3) Short stature: patients with a late diagnosis of CAH had extremely advanced bone ages of +6.3 to +9.5 years, leading to severely reduced final height of 137 to 150 cm in adult patients. Patients tended to follow height percentiles of genetic females. One pubertal patient was suicidal due to short stature. (4) Central precocious puberty (CPP): prolonged exposition to adrenal androgens led to CPP in one patient. He was treated with GnRH analogues until gonadectomy. Conclusions Patients with CAH and complete virilization have a high risk of being diagnosed late. There are major problems and uncertainties of the patients' families and the treating physicians concerning gender assignment. Gender identity is disturbed in some patients. In addition, multiple surgical procedures are necessary and short stature as well as central precocious puberty might be important to avoid late sequelae. While some surgical interventions are probably unavoidable, most of these issues could be resolved with an early diagnosis. Thus, especially for these patients, a neonatal screening programme for CAH would be of paramount importance.

Background: CNS-irradiation in prepubertal children with leukemia or brain tumors can lead to precocious or in high doses to delayed puberty. The underlying mechanisms of these disorders are unknown. Methods: A new animal model of experimentally induced pubertal disorders by cranial irradiation has been developed. In infantile or juvenile (12-23 days old) female rats precocious or delayed puberty have been induced by selective cranial Co60-irradiation (4-18 Gy). At age of 32-38 days or 3 months relevant hormone parameters have been studied basal and after stimulated conditions. Results: Low radiation doses (5 or 6 Gy) led to accelerated onset of puberty as well as elevated LH- and estradiol levels. High radiation doses (9-18 Gy) caused retardation of sexual development, lower gonadotropin levels and growth retardation associated with growth hormone deficiency. After cranial irradiation with 5 Gy the release rates of the inhibitory neurotransmitter gamma-aminobutyric-acid (GABA) from hypothalamic explants were significantly lower (p < 0,05). The gonadotropin-releasing-hormone (GnRH) expression in the hypothalamic preoptic area of irradiated animals (5 Gy) was significantly higher than in controls (p < 0,05). Conclusion: The GnRH-pulse generator is very radiosensitive as low dose irradiation causes precocious puberty, whereas high dose irradiation is associated with delayed sexual maturation. Radiation induced precocious puberty might be caused by damage to inhibitory GABAergic neurons leading to desinhibition and premature activation of GnRH neurons. Our animal model of cranial irradiation seems to be suitable to study neurotransmitter disorders, molecular mechanisms and potential preventive intervention of radiation induced pubertal changes.

Cranial irradiation in prepubertal children with leukemia or brain tumors can lead to precocious or in high doses to late puberty. To unravel the underlying mechanisms, we developed a rat model with selective cranial Co-60-irradiation technique. Infantile (12-16 d old) or juvenile (21-23 d old) female Sprague-Dawley rats received a single dose of 4, 5, 6, 9 or 2 x 9 Gy (at days 21 and 23). Each group consisted of 7-20 animals. High radiation doses (9 Gy and more) caused retardation of sexual development, whereas low radiation doses (5 or 6 Gy) led to accelerated onset of puberty in 20% of infantile irradiated rats animals as determined by vaginal opening. interestingly, at peripubertal age (postnatal day 32-34), 5 or 6 Gy infantile irradiated rats had significantly higher serum LH levels stimulated by GnRH and estradiol levels (p < 0.05). 2 x 9 GY irradiated rats had at the age of 3 mo a marked growth retardation and significantly lower GH levels than the controls (p < 0.05) whereas prolactin, FSH, TSH, T-4, and corticosterone levels were comparable with controls. These studies demonstrate that the GnRH-pulse generator is very radiosensitive as precocious activation occurred after low dose irradiation (5 or 6 Gy) of infantile rats without any other endocrine disorder. High radiation doses (9 or 2 x 9 Gy) induced retardation of sexual maturation and later on growth hormone deficiency. Moreover this model of cranial irradiation seems to be suitable to study the molecular mechanisms of radiation induced pubertal changes.

Testolactone is used to treat conditions with excessive estrogen synthesis, e.g. gonadotropin-independent precocious puberty in McCune-Albright syndrome (MAS). Unfortunately, daily treatment with testolactone requires 3 to 4 doses (10-20 tablets) and even at these doses it is sometimes ineffective. We treated a patient with MAS (cafe-au-lait spots; thelarche at age 2-(6)/(12) yr; menarche at 5-(5)/(12) yr; accelerated bone age [BA 10 yr]) with the highly selective aromatase inhibitor anastrozolle (1 mg once per day). Tamoxifen 1 mg/kg per day was added for 1 year but was discontinued when an ovarian cyst developed with markedly elevated estradiol levels. Estradiol levels returned to normal after resuming anastrozole-only treatment and accelerated BA progressed only 6 months during 21/2 years of treatment. The potent estrogen suppressive action and simple dosage regimen of anastrozole suggest it may be advantageous compared to other aromatase inhibitors such as testolactone or anti-estrogens.

Aim: To determine whether primary or secondary growth hormone (GH) deficiency has a causative role in linear growth retardation, a key feature in Rett syndrome (RTT). Methods: In 38 patients with Rett syndrome a variable set of investigations was performed including assays of growth and thyroid hormones, gonadotropins, gonadal and adrenal steroids and determination of bone age. Not all measurements were attainable from all patients. In three patients the 24-h growth hormone secretion profile was evaluated using the pulsar method. Results: The bone age determined in 24 patients was found to be normal in 8, retarded in 9 and accelerated in 7 patients. Insulin-like growth factor (IGF)-1 was low in 8 out of 23 patients. IGF-binding protein (IGFBP)-3 and insulin and arginine-stimulatcd growth hormone secretion were both nornial, indicating normal GH secretion in the majority of patients. The 24-h CH secretion profile in the first patient showed a normal day/night rhythm and a normal increase in nocturnal GH secretion. The second patient's overall GH secretion was normal but there was no day/night rhythm. The third patient showed borderline low GH secretion. Normal age-appropriate plasma values were found for the thyroid hormones (T4, TSH), TSH-night rhythm, oestradiol, prolactin and cortisol (08.00, 18.00). Conclusion: Our study provides no evidence that growth retardation in RTT is caused by growth hormone deficiency. A disturbed hypothalamic control cannot be excluded but it is unlikely that this is the major cause of growth retardation in RTT.

We report a female newborn with characteristic signs of Antley-Bixler syndrome (ABS) such as midface hypoplasia, radiohumeral synostosis and multiple joint contractures. The newborn also presented ambiguous genitalia, stage Prader V, and congenital adrenal hyperplasia. The mother experienced midterm virilization due to a pregnancy luteoma. Her elevated androgen levels and virilization symptoms normalized post partum without treatment. The newborn had elevated serum testosterone and 17-OH-progesterone levels which remained elevated because of a 21-hydroxylase deficiency. The child's treatment in order of priority was: hydrocortisone substitution, craniofacial/ skeletal anomaly management and surgical correction of the external genitalia. Mutations in the genes for fibroblast growth factor (FGF) 8 and receptors FGFR1, FGFR2, and FGFR3 were not detected. Conclusion A newborn girl with manifestations of the Antley-Bixler syndrome showed severe virilization probably caused by the association of a mild 21-hydroxylase deficiency and maternal hyperandrogenism due to a pregnancy luteoma. Abnormalities of androgen metabolism may be responsible for virilization reported in other cases of the Antley-Bixler syndrome.

Background. In patients suffering from thalassemia major, hemosiderosis frequently causes endocrine disorders. We investigated the development of glucose tolerance disorders and the influence of therapeutical interventions such as intensified chelation therapy and diet. Methods and patients. 60 patients with thalassemia major, ages ranging from 4 to 36 years,treated regularly with both subcutaneous desferrioxamine infusions and erythrocyte transfusions, were investigated for endocrine disorders. Oral and intravenous glucose tolerance tests as well as intravenous glucagon challenge were used to investigate the insulin secretion. In patients with impaired glucose tolerance the influence of intensified (intravenous) chelation therapy and dietary interventions on blood glucose and serum insulin levels were studied. Results. In patients with thalassemia major, disturbed glucose tolerance appears to be one of the four most common endocrine disorders in the second decade of life and later. In the early stages of the disease, glucose tolerance disorders were associated with hyperinsulinemia; in later stages insulinopenic diabetes develops due to p-cell exhaustion. In some patients in the early stages of the disease, intensified chelation therapy or dietary treatment only improved their glucose tolerance. Conclusion. Especially for thalassemia patients in the early stages of glucose tolerance disorders, intensified desferrioxamine treatment and diet can be of benefit and in some cases retard the manifestation of diabetes mellitus. These treatments do not, however, change the requirement for insulin substitution at an advanced stage of disturbed glucose tolerance.

Gonadotropin releasing-hormone (GnRH) analogues contain amino acid substitutions of the native decapeptide. Depending on the substitutions, the analogues have GnRH agonistic or antagonistic properties. GnRH agonists are the established treatment in cases of central precocious puberty caused by premature activation of the hypothalamic GnRH pulse generator. Much less data exist on the use of GnRH antagonists to influence the onset of puberty. Using the GnRH antagonist cetrorelix we conducted a 5 day treatment of peripubertal male rats (cetrorelix group n=12, 100 mu g/d intraperitoneally injected; placebo n=10, NaCl 0.9% intraperitoneally injected) from postnatal day 32 to 36 and decapitated on postnatal day 37 to investigate the effects on pubertal development, serum gonadotropin and testosterone levels as well as the GnRH release from explanted hypothalami. A control group of 5 male rats was added for hypothalamus superfusion experiments on day 25. We observed no progress of testicular development in the cetrorelix group. Cetrorelix injected rats had lower testicular weights (531+/-13 versus controls 819+/-25 mg, mean+/-SEM, p<0.0001). 12 h after the last injection testosterone levels were in the castrate range (serum testosterone, median controls: 1.7 ng/ml, median cetrorelix <0.30 ng/ml, p<0.001), and they showed lower serum LH and FSH compared to the same age placebo group. After decapitation the preoptic mediobasal hypothalamic area (POA/MBH) was dissected from 5 randomly selected rats from each treatment group and the release rates of GnRH were determined in superfusion experiments: The hypothalamic GnRH secretion was comparable in the CET and the same age placebo rats but significantly higher than in the 25 day old control group. Conclusion: The GnRH antagonist cetrorelix inhibits the pituitary-gonadal axis in peripubertal male rats and may be effective in treating central precocious puberty in males.

Background and purpose: Endovascular therapy (ET) is superior to intravenous thrombolysis (IVT) in selected patients with anterior circulation large vessel occlusions. However, it is unclear if this positive effect also applies to patients with extensive early ischaemic changes. The aim of this study was to analyze the impact of the Alberta Stroke Program Early Computed Tomography Score (ASPECTS) on the CT angiography source images (SI) on outcome after ET or IVT. Methods: Using our prospectively obtained stroke database and the admission SI-ASPECTS divided into three groups (0-5, 6-7 and 8-10), primarily the rates of good outcome = [modified Rankin Scale (mRS) <= 2 at discharge] after either ET (n = 255) or IVT (n = 479) were compared. Results: A favorable SI-ASPECTS (8-10) was present in 501 patients, 132 patients had a moderately favorable SI-ASPECTS (6-7) and 101 patients had an unfavorable SI-ASPECTS (0-5). Irrespective of the treatment modality, no patient with an unfavorable SI-ASPECTS had a good outcome and 38% died during hospital stay. Whilst significantly more patients with a favorable SI-ASPECTS had a good outcome after ET than after IVT (51% vs. 35%, P < 0.01), there was only a non-significant trend towards a good outcome after ET than after IVT in patients with a moderately favorable ASPECTS (25% vs. 14%, P = 0.1). Conclusion: Patients with extensive early ischaemic changes on CT scans (SI-ASPECTS <= 5) might not profit from ET. The impact of ET on outcome in patients with moderately favorable SI-ASPECTS should be addressed in further trials.

Background: Since 1989 the use of iodized salt has been allowed in Germany, additional supplementation with iodide tablets has been recommended during pregnancy and lactation. This study was undertaken to clarify whether the iodine intake of neonates and young infants improved since then. Patients and methods: In the first part of the study the urinary iodine excretion of 52 newborns and their mothers in 1998 was compared to data of similar studies 1983 in the area of Gottingen and 1982 in the areas of Heidelberg and Rothenburg, Germany. All these are geographically low-iodine areas. In the second part the iodine supply of infants in 1998-1999 under feeding with mother's milk or formulas in 1998 and 1999 was obtained by measuring iodide concentrations in urine and milk using a high pressure liquid chromatography (HPLC) method. Results: 45% of pregnant women were without iodide supplementation in 1998. In 1998 the median urinary iodide concentration during the first week of life was 4,3 mug/dl, which was more than twice that found in 1983 (1,75 mug/dl). Infants feeded by mother's milk without maternal iodine supplentation or by semi-elementary diet had the lowest urinary iodine excretion, whereas significantly higher values were measured when feeding formulas for term or preterm infants. Conclusions: The iodine intake of newborns has markedly improved during 15 years. The WHO criterias for adequate iodine supply (TSH < 5 U/ml and urinary iodine >/ = 1 mug/dl) were only partly fulfilled in Gottingen indicating that a mild iodine deficiency still exists with the risk of iodine deficiency disorders.

We investigated a four-generation family of German ancestry with distal myopathy. Four individuals in two generations were affected. Foot and toe extensor paresis progressing very slowly over decades was the core neurological sign, reflected by fatty infiltration of the lower leg extensor muscles on muscle MRI. Additionally, finger extensor paresis was present in two patients and quadriceps muscle paresis in one. Distal sensory signs had initially given rise to the diagnosis of axonal Charcot Marie Tooth (CMT) disease. Two patients had extended verrucae of their foot sole, which may or may not be part of the disease spectrum. All four patients had a novel c.4645G > C mutation in exon 34 of the MYH7 gene that was not present in three clinically unaffected family members. Muscle biopsy of one patient revealed a myopathic pattern associated with type 1 muscle fibre atrophy and core-like lesions in many muscle fibres consistent with a myosin-related myopathy. We conclude that some of the typical clinical signs such as extensor weakness of the big toe and the little finger may only develop in the further course of the disease. (C) 2016 Elsevier B.V. All rights reserved.

Background: Craniopharyngiomas are tumorous embryogenic malformations. As the survival rate after craniopharyngioma is high (92%), prognosis and quality of life (QoL) in survivors mainly depend on adverse late effects such as obesity. Patients and methods: We analyzed 214 children and adolescents with craniopharyngioma. The records of 185 patients (86%) were available for retrospective analysis of weight profiles and risk factors for obesity. Quality of life (QoL) was measured in 145 patients by the Fertigkeitenskala Munster/Heidelberg score (FMH) and in 77 patients by PEDQOL questionnaire. Results: Eighty-two of 185 patients (44%) developed severe obesity (body mass index [BMI] > 3 SD). Obese patients were compared with 79 patients (43%) who kept normal weight (BMI < 2 SD). No differences between obese and normal weight patients were found in terms of gender distribution, age at diagnosis and follow-up period. However, the BMI SDS at the time of diagnosis was higher (p < 0.0001) in patients who developed obesity than in those who did not. Furthermore, obese patients presented with bigger tumors (p < 0.05) and a higher rate of a hydrocephalus requiring a shunt (p < 0.05) and hypothalamic involvement (p 0.05). The mothers of patients who developed severe obesity had a higher BMI (p < 0.001) at the time of diagnosis. Obese patients had a higher height-SDS at diagnosis (p < 0.05) and at the time of last follow-up (p < 0.05) when compared with normal weight patients. A prediction model for severe obesity after craniopharyngioma was calculated by logistic regression based on the risk factors: patient's BMI > 2 SD at diagnosis (p < 0.05; odds ratio: 16.4), hypothalamic involvement (p < 0.05; odds ratio: 3.4) and maternal BMI > 25 kg/m(2) (p < 0.05; odds ratio: 4.6). Significant increases in BMI (p < 0.001) occurred during the early post-operative period especially during the first three years after diagnosis. FMH percentiles correlated negatively with BMI SOS (Spearman r: -0.37; p < 0.001). Children with craniopharyngioma rated their QoL more negative (p < 0.05) in regard to physical abilities, cognitive functioning and social functioning when compared with healthy children of the same age group. Severely obese patients with craniopharyngioma estimated their QoL lower (p < 0.05) for all domains except for autonomy, cognition and familial integration in comparison with non-obese patients. Conclusion: Hypothalamic tumor involvement and familial disposition for obesity are risk factors for the development of severe obesity in patients with craniopharyngioma. As weight gain starts early after diagnosis and severe obesity causes a reduction in QoL, early therapeutic efforts should be considered in patients at risk. To confirm our results the prospective multicenter study Kraniopharyngeom 2000 on children and adolescents with craniopharyngioma was initiated (www.kraniopharyngeom.com).

Patients with childhood-onset craniopharyngioma (CP) often suffer from obesity. We evaluated two important etiological factors of obesity development, energy intake and physical activity. Energy intake was supposed to be high due to a disturbed hypothalamic regulation of appetite. We used a validated nutritional diary to determine the 1-wk food intake in 27 CP patients (12 with intrasellar tumors and 15 with hypothalamic tumors) and 1027 controls who were a representative sample of the 7- to 16-yr-old German population. In 2 accelerometry settings, we determined movement counts indicating physical activity. Nineteen CP patients were comparable to 26 controls for age and body mass index. One setting was a clinical one during weight reduction; the other was an outpatient setting. Daily energy intake was 1916+/-677 kcal (mean+/-SD) in intrasellar CP patients, 2075+/-877 kcal in hypothalamic CP patients, and 2476+/-815 kcal in non-CP controls. Patients suffering from CP showed fewer movement registrations [clinical setting, 228 vs. 298 cpm for obese controls (P=0.01); out-patient setting, 228 vs. 282 cpm for controls ( P=0.08)]. Differences were most pronounced during leisure time (382 cpm in CP patients vs. 546 cpm in obese controls; P=0.002; clinical setting). Our findings suggest that reduced physical activity, rather than increased energy intake, in CP patients is responsible for the obesity development noted in these subjects.

Central precocious puberty is commonly treated by gonadotropin releasing hormone (GnRH) agonists. To compare modes of action and effectiveness of GnRH analogues and assess treatment combinations of agonistic (triptorelin) and antagonistic (cetrorelix acetate) GnRH analogues with established treatment, we used prepubertal 31-d-old ovariectomized female rats. Strongest inhibition of LH and FSH occurred after 2-d treatment with antagonist alone (LH 0.08 +/- 0.02 versus 3.2 +/- 0.56 ng/mL in controls; FSH 10.8 +/- 2.8 versus 44.2 +/- 5.0 ng/mL in controls, p < 0.001). Combined agonist/antagonist was second most effective of the treatments (after 5 d treatment, LH 0.52 +/- 0.15 versus 4.9 +/- 1.1 ng/mL in controls; p < 0.01). Pituitary gonadotropin subunit LHbeta mRNA levels were inhibited in all groups except controls, but pituitary GnRH receptor mRNA was stimulated by agonist yet unaffected by combined analogues. Explanted ovaries were incubated with either analogue, both 10(-6) M. After 4 h, GnRH receptor mRNA levels were significantly reduced by antagonist. but not agonist. To verify puberty-inhibiting effects of GnRH analogues, we used 26-d-old female rats with androgen-induced precocious puberty after injecting subcutaneously single 300 mug danazol on postnatal d 5. Single application of cetrorelix depot (cetrorelix embonate) reduced serum estradiol levels and pituitary LHbeta expression; GnRH receptor mRNA levels were down-regulated in the pituitary and ovary (p < 0.05). In androgen-induced precocious puberty model, single injection of antagonist effectively arrests premature hormonal activation and down-regulates pituitary and ovarian GnRH receptors. We conclude that GnRH analogue combination and especially antagonist alone treatment most directly suppress gonadotropin levels. This implies that early treatment gonadotropin flare-up associated with agonist treatment is avoidable.

The present study shows that stress signaling plays a role in differentiation of K562. PANC1, HT29 and HL60 tumor cells: (1) Butyrate induced differentiation in K562, PANC1 and HT29 cells can be inhibited by SB203580. a specific inhibitor of p38 stress activated protein kinase. (2) Heat shock and hyperosmolarity increase expression of differentiation markers in K562. HT29, HL60 and in K562, PANC1, and HT29 cells, respectively. (3) Conversely. environmental stress induced differentiation in K562, HT29. and PANC1 cells can be inhibited by SB203580 and quercetin, a compound with heat shock pathway inhibiting activity. (4) Butyrate and environmental stress enhance either additively or synergistically differentiation of K562, HT29. PANC1 or HL60 cells, respectively. Stress signaling pathways might be an interesting pharmacologic target for differentiation therapy of malignant disease. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.