Somatostatin cells in human somatotropic adenomas.

Data from our group have shown that the human adenomatous and normal anterior pituitary may be the source of somatostatin (SRIH). SRIH-producing cells were identified in two somatotropic adenomas. Immunoreactive SRIH cells were present in both cases.

Immunocytochemistry of four mixed pituitary adenomas and intrasellar gangliocytomas associated with different clinical syndromes: acromegaly, amenorrhea-galactorrhea, Cushing's disease and isolated tumoral syndrome.

Four tumors consisting of pituitary adenomatous cells (AD) intricated with ganglion cells (GC) were studied. Each case was associated with a different clinical syndrome: acromegaly, amenorrhea-galactorrhea, Cushing's disease and isolated tumoral syndrome with no hormonal hypersecretion. (a) In the case with acromegaly, immunoreactive growth hormone (IR-GH) was present in 80% of AD.

Stimulation of oxygen consumption at the cytochrome A3 level inhibits aldosterone biosynthesis from 18-hydroxycorticosterone.

A mitochondrial preparation from duck adrenal gland was used, under aerobic conditions, to show that the oxygen requirement for the last step of aldosterone biosynthesis (transformation of 18-hydroxycorticosterone into aldosterone) is at the cytochrome P-450 level only. Vitamin C and tetramethyl-p-phenylene-diamine (TMPD) were used to increase oxygen consumption at the cytochrome a3 level, thereby decreasing its availability to cytochrome P-450. The vitamin C plus TMPD system acts as an 'oxygen trap'.

Specific localization of plasma corticosteroid-binding globulin immunoreactivity in pituitary corticotrophs.

The prevailing concept is that steroids are bound to specific receptors inside target cells, whereas extracellular and especially plasma binding of these steroids are due to specific transport proteins. The purpose of this study was to investigate the presence of corticosteroid-binding globulin (CBG) in guinea pig pituitary by immunohistochemical methods. Both immunofluorescence and an immunoperoxidase (unlabeled antibody-peroxidase-antiperoxidase) method using antiserum to guinea pig CBG gave identical results.