The investigation of steroids in compartments of the genital tract of boars revealed that in the tubular fluid a pattern apparently exists which is unique in this compartment. It is characterized by high concentrations of unconjugated testosterone (35 ng/ml) and even higher amounts of oestradiol-17\g=b\(42.6 ng/ml) whereas in other compartments oestrone is the predominant oestrogen. At least in the ejaculate half of the total amount of oestrogens is bound to sperms and it is concluded that sperms act as a carrier for oestrogens. The accessory sex glands contribute to ejaculate concentrations to a varying degree (unconjugated testosterone 55%, conjugated testosterone 20%, unconjugated oestrogens 22%, conjugated oestrogens 12%) as could mainly be demonstrated by vasectomy with and without administration of hCG.Increasing the frequencies of ejaculations (up to three times a day) shows that the steroid transfer into the ejaculate is a rapid process.

The Ah receptor (AhR) is a ligand transcription factor mediating toxic effects of chemicals such as dioxins. The 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD) and the coplanar polychlorinated biphenyl 126 (PCB 126) are member of the polyhalogenated aromatic hydrocarbons family exerting a variety of toxic effects in a tissue-specific and species-specific manner including thyroid function. In the present study, we aimed to investigate the effects of TCDD (1 and 10 nM) and dioxin-like PCB 126 (306 nM) on the AhR signaling pathway and on the gene expression profiles of key factors involved in thyroid function, including thyroglobulin (TG), thyroid peroxidase (TPO), the sodium iodide symporter (NIS), TSH receptor (TSHR), and cathepsins (Cat B and L), using a primary porcine thyrocyte culture as the experimental model. AhR and ARNT expression was detected both as mRNA and on the protein level. Expression did not vary upon treatment with either TCDD or PCB 126. However, treatment with TCDD and PCB 126 induced an AhR signaling response, as indicated by the expression of the AhR-target gene cytochrome P-450 1A1 (CYP1A1). Both 10 nM TCDD and PCB 126 treatment induced a significant downregulation in the expression of NIS and cathepsin B without affecting any of the other parameters investigated. In conclusion, these data indicate that (a) thyrocytes are targets of TCDD and TCDD-like compounds and (b) there is evidence for two independent most likely AhR-mediated molecular mechanisms, by which these compounds negatively interfere with thyroid function.

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Summary Ret/PTC oncogene has been described with a frequency of 2.5-30% in papillary thyroid carcinomas. We examined the expression of ret/PTC in 99 German papillary thyroid carcinomas, including two recently described new variants of ret/PTC3 and identified eight ret/PTCpositive tumours (8%) but none with the new variants.

Summary. Two experiments were carried out to monitor influences on the uterine electromyographic activity (EMG) 0\m=.\81;P < 0\m=.\01;n = 10) but not the frequency was observed. In Exp. 2 no significant change in contractile activity was found for the sal i ne\x=req-\ infused group and the controls over the 11-h recording periods. After infusion of saline with oestrogens the frequency increased significantly (P < 0\m=.\001) from 14\m=.\0\ m=+-\3\ m=. \ 1 contractions/h during the first hour up to a maximum of 31\m=.\2\m=+-\ 3\m=.\9/hat 2 h after infusion. Compared to the pretreatment period the frequency remained significantly elevated during the 3rd (28\m=.\7\ m=+-\2\m=.\3/h; P < 0\m=.\05) and 4th (20\m=.\2 \m=+-\ 3\m=.\9/h; P < 0\m=.\05) hour after infusion. Seminal oestrogens therefore stimulate uterine contractions at Day 0 and may play a physiological role for sperm transport.