Macroprolactinoma associated with Cushing's disease, successfully treated with cabergoline.

Multiple pituitary hormone hypersecretions have already been described, but the co-occurrence of PRL and ACTH excess is very rare. To our knowledge, medical treatment with cabergoline only, avoiding pituitary surgery and radiotherapy in this type of tumor has never been reported before. This case report deals with a 31-yr-old man affected with a macroprolactinoma associated with a florid clinical image of Cushing's disease.

Marked species specificity of guinea pig luteinizing hormone: validation of a bioassay.

The Guinea pig is a potentially interesting alternative small animal model for the study of the neuroendocrine regulation of reproduction. However, appropriate gonadotropin assays are not widely available for this species. The aim of the present study was to validate a bioassay procedure for guinea pig luteinizing hormone (LH).

Guinea-pig gonadotropin-releasing hormone: immunoreactivity and biological activity.

The DNA sequence of the encoding gene predicts a unique structure for guinea-pig gonadotropin-releasing hormone (GnRH). We assessed the immunoreactivity of synthetic mammalian GnRH, of a synthetic peptide with predicted guinea-pig GnRH structure, and of extracts from rat and guinea-pig hypothalami, using two different RIA systems. Whereas immunoreactivity of mammalian and guinea-pig GnRH was rather similar when using an antiserum with conformational specificity for mammalian GnRH (Root RR-5 antiserum), binding of both peptides to an antiserum with sequential specificity (Kelch R-13 antiserum) was markedly different.

Serum leptin levels in healthy ageing men: are decreased serum testosterone and increased adiposity in elderly men the consequence of leptin deficiency?

Objective: The limited information on serum leptin levels in elderly men suggests the occurrence of an age-related decrease, with disruption of the relationship between fat mass and leptin levels. A relative leptin deficiency might thus be implicated in the increase of fat mass and decrease of serum testosterone levels in elderly men. Therefore, we have reevaluated the age-related changes in serum leptin levels and their relationship with adiposity and androgen levels in a large group of community dwelling men.