An oestrogen-producing seminoma responsible for gynaecomastia.

In feminising testicular tumours, oestrogens can be either secreted by the tumour itself or produced by normal Leydig cells in response to paracrine and/or endocrine stimulation by hCG. Typical hormonal Leydig cell tumour patterns include: plasma oestradiol levels > 300 pmol/l on day 3 following an hCG injection, reduced plasma testosterone, and normal plasma hCG and gonadotrophin levels. Except for elevated plasma oestradiol levels, opposite results are observed in seminomas.

Na(+)-H+ exchanger expression in vascular smooth muscle of spontaneously hypertensive and Wistar-Kyoto rats.

The Na(+)-H+ exchanger has important modulatory effects on vascular smooth muscle cell proliferation and contractility. Increased Na(+)-H+ exchange activity is a general property of many tissues, including mesenteric artery and cultured vascular smooth muscle cells, in the spontaneously hypertensive rat (SHR). In the present work, we investigated whether alterations in the steady-state levels of specific Na(+)-H+ exchanger mRNA isoforms (NHE-1 through NHE-4) are associated with the observed increases in exchanger activity.