False positive 131I total body scan due to bilateral polycystic renal disease.

A radioiodine accumulation at Total Body Scan (TBS) in patient who has been thyroidectomized for a differentiated thyroid cancer is usually a reliable indicator of recurrent or metastatic functioning thyroid tissue. Radioiodine uptake may be usually observed at TBS in areas such as the intestinal tract, liver, salivary glands, bladder, and also in case of blood vessel ectasia. This report describes a patient with a bilaterally significant 131I uptake in upper abdomen. By ultrasound and radionuclide imaging the 131I uptake was proven to be due to radioiodine accumulation caused by bilateral polycystic renal disease.

Role of peripherally infused angiotensin II on the human hypothalamic-pituitary-adrenal axis.

Although angiotensin II (AII), a potent vasoconstrictor agent, has been reported to stimulate the hypothalamic-pituitary-adrenal (HPA) axis of laboratory animals, its role in the regulation of this axis in humans appears to be controversial. To examine this question, AII (Val5-AII amide) was infused intravenously into 19 male normal volunteers at the doses of 0, 1, 3.3 and 10 ng/kg/min for 30 min. AII had no effect on plasma ACTH, cortisol, corticotrophin-releasing hormone, arginine vasopressin, and atrial natriuretic factor concentrations, nor did it increase systolic or diastolic arterial blood pressure. On the other hand, AII caused a dose-dependent increase of plasma aldosterone concentrations, suggesting that the doses and the mode of AII infusion were effective. Thus, our data show that peripherally infused AII has no detectable effect on the HPA axis function in humans, at doses capable of stimulating plasma aldosterone secretion, its specific target hormone.

Generation of reactive oxygen species in subgroups of infertile men.

The capacity to generate reactive oxygen species (ROS), both basally and after stimulation with the calcium ionophore A23187, was examined in the motile fraction of sperm isolated after swim-up from the semen of 10 naturally fertile men and three groups of infertile patients. The latter included: (1) men with a non-bacterial inflammation of the genital tract (n = 10); (2) men unable to impregnate their partners during an intra-uterine insemination programme (IUI) (n = 8) and their matched controls (n = 6); and (3) men with hypogonadotrophic hypogonadism (HH) who remained infertile after induction of spermatogenesis with gonadotrophin or gonadotrophin-releasing hormone therapy (n = 3) and their matched controls (n = 3). The levels of ROS production were elevated in the sperm of some infertile men with inflammation of the genital tract compared to those found in 10 naturally fertile men. In addition, sperm from those patients who remained infertile after an IUI programme produced higher amounts of ROS compared to their control group who became fertile. Similarly, the production of ROS by sperm from three patients with HH who remained infertile was significantly higher than those of the three men who became fertile. These data suggest that an excessive production of ROS by sperm may explain some cases of idiopathic male infertility.

lntra- and Inter-Individual Variability in Growth Hormone Responses to Growth Hormone-Releasing Hormone*.

Abstract Normal subjects show a wide range of growth hormone (GH) responses to growth hormone-releasing hormone (GHRH) stimulation, but it is uncertain whether this variability reflects differences among individuals or whether it would also be observed on repeated tests of the same subject. To clarify this, we tested nine normal men repeatedly with iv bolus doses of 1 mug/kg GHRH(1-44)NH(2). Most subjects showed wide variations in their GH responses on repeated testing, and the intra-individual variability was nearly as great as the inter-individual variability in responses, accounting for about two-thirds of the overall variance. A minority of subjects had lower and less variable responses. Ultradian fluctuations in hypothalamic somatostatin secretion may account for this marked intra-individual variability.

Pituitary and adrenal response to ovine corticotropin-releasing hormone in women with polycystic ovarian syndrome.

It has been hypothesized that there is an adrenal abnormality in the polycystic ovary syndrome (PCO). This study was undertaken to examine this hypothesis in a more physiological way, by enhancing the ACTH secretion in response to ovine corticotropin releasing hormone (oCRH) injection so that adrenal androgen and glucocorticoid responsiveness to endogenous stimulation could be examined. Plasma ACTH and the ACTH and cortisol (F) response to oCRH were normal. The plasma T and dehydroepiandrosterone (DHEA) responses were also normal. The androstenedione (A) response, however, was exaggerated. This study supports the hypothesis that the adrenal gland in patients with PCO produces increased amounts of androstenedione in response to ACTH stimulation.