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Anterior hemi-pituitary glands from intact female and ovariectomized (OVX) rats were incubated with or without a maximally effective dose of LRH. During an 8 h incubation, LRH-stimulated release of FSH by pituitary glands from intact rats was biphasic: an initial slow rate of release and, from 2 to 8 h, an enhanced rate of release. Basal release was low up to 4 h, after which a marked increase of the rate of release was measured: from 6 to 8 h there was no difference between the rates of basal and LRH-stimulated release. Basal and LRH-stimulated release of FSH by pituitary glands from OVX rats were high and approximately constant during an 8 h incubation.Both basal and LRH-stimulated release by glands from intact as well as OVX rats were protein synthesis dependent. During the incubations an LRH-independent synthesis of FSH was measured. The results suggest that this synthesis is involved, either directly or indirectly, in increasing the rate of basal release of FSH after 4 h. A comparison of release and synthesis of FSH with those of LH reveals characteristic differences.

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Screening for congenital hypothyroidism for all newborns of the former western parts of the city of Berlin was instituted in 1978 by determination of the TSH levels in dried filter paper blood spots of the 3rd to 5th day of life. Since 1991 the newborns of the former eastern parts have been also included in the same screening program. From 1978 to 1995 a total number of 104 newborns with permanent congenital hypothyroidism have been detected resulting in a prevalence of congenital hypothyroidism of 1:3800. The etiological diagnosis of hypothyroidism was made by imaging studies (ultrasonography or 99mTc scintigraphy) and assessment of serum thyroglobulin and thyroid hormone levels. Using this approach in 37 children (30 female, 7 male) the diagnosis of athyrosis, in 20 children (15 female, 5 male) the diagnosis of ectopy and in 21 children (18 female, 3 male) the diagnosis of thyroid hypoplasia was made, 16 children (8 female, 8 male) had a normally sized gland and 4 (1 female, 3 male) had congenital goiter. In 86% of all patients the age at onset of thyroxine (L-T4) replacement therapy was 8 or 9 days of life (3-42 days) and the median initial L-T4 dose was 14 micrograms/kg/day (10-16 micrograms/kg/day). The intellectual outcome of 77 children (2-16 years) was studied and normal scores for the intelligence (IQ) and developmental (DQ) quotients were found in 71 (92%). Outcome was not correlated to the age at onset of treatment, the initial dose and the severity of hypothyroidism, but there was a positive correlation of the socioeconomic status of the family and the IQ of the patients. The results of the screening program in Berlin document that an early and efficient thyroxine replacement can normalize the intellectual outcome of patients with congenital hypothyroidism independent of the severity of the disease as assessed by the residual thyroid function detectable at diagnosis.

Inhibin-like activity in steroid-free bovine follicular fluid (bFF) is demonstrated using an in vitro technique with hemi-pituitary glands from intact female (second day of dioestrus) and ovariectomized rats: synthesis as well as basal release of FSH, but not of LH, are inhibited profoundly. The results confirm and extend data from other investigators on the action of inhibin-like material. The effect of the inhibin-like activity is shown to be reversible, as synthesis and the rise of basal release are restored when bFF is withdrawn from the incubation medium. Synthesis of FSH seems to be inhibited earlier than basal release, and it is suggested that the inhibin-like material acts only directly on FSH synthesis. Some possibilities of the mechanisms of action of inhibin-like activity are discussed.In a previous paper we reported that basal release of FSH by pituitary glands from female rats in vitro spontaneously became elevated to a much higher rate after 4 h of incubation (Jenner et al. 1982).The increased rate of release persisted up to at least 12 h of incubation and was fully dependent on protein synthesis. We suggested that this rise of basal release of FSH could be due to the withdrawal of a specific ovarian feedback control, such as exerted by inhibin-like factor(s) and/or steroid hor¬ mones.Inhibin was originally postulated by McCullagh (1932) as a non-steroidal testicular factor which specifically suppresses FSH release. Subsequently, inhibin-like activity, of protein nature, has been detected in ovarian and testicular fluid of several species (Setchell & Sirinathsinghji 1972;de Jong & Sharpe 1976;Marder et al. 1977;Welschen et al. 1977;Daume et al. 1978;Davies et al. 1978;DePaolo et al. 1979b) and in medium from cul¬ tured rat Sertoli cells (Steinberger & Steinberger 1976;de Jong et al. 1978). These observations favour a physiological role for inhibin in the repro¬ ductive system.In the present work we investigated whether inhibin-like activity, as present in charcoal ex¬ tracted bovine follicular fluid, bFF (Welschen et al. 1977), could prevent the rise of basal release and the synthesis of FSH, which is normally seen in our incubation system. These results were compared with those of bFF on LH. Materials and Methods AnimalsFemale rats from the Wistar-derived colony were housed in a temperature-and light-controlled room: 22°C, lights on from 5 a.m. till 7 p.m. Vaginal smears were taken daily at 9 a. m. and only adult rats with regular 4-or 5-day cycles were used on the second day of dioestrus (Q Di-II). Ovariectomized (OVX) rats (0) were used 14 days after gonadectomy. IncubationsThe rats were killed by decapitation. After removal of the posterior lobe, the anterior pituitary glands were hemisected and the halves were placed into different incuba¬ tion flasks containing 1 ml medium TC 199 (Difco Labo¬ ratories). Each flask ultimately received two pituitary halves. All incubations were carried out in a thermostatic shaking-bath at 37°C under continuous shaking and gassing with 95 % 02 and 5 % C02.After ...