Long-term culture of rat mammotrope and somatotrope subpopulations separated on continuous Percoll density gradients: effects of dopamine, TRH, GHRH and somatostatin.

Unlabelled: Normal adult female rat mammotrope and somatotrope subpopulations were separated on continuous Percoll density gradients according to differences in their density. Viable cells were recovered in 16 fractions. The cells from each fraction were cultured during 7 days after which period 4-h incubations were performed.

Heterogeneity of pituitary adenoma cell subpopulations from acromegalic patients obtained by Percoll density gradient centrifugation.

Unlabelled: Pituitary adenoma cells from 6 acromegalic patients were separated on continuous Percoll density gradients according to differences in their density. Two adenomas produced GH only in culture, the other 4 adenomas produced either GH and PRL (one adenoma) or GH and alpha-subunit (one adenoma) or GH, PRL and alpha-subunit (2 adenomas). The cell subpopulations obtained by this technique differed in the amount of hormone production per 10(5) cells: GH release decreased from the low density fractions to the higher density fractions in 5 of 6 adenomas.

Glycoprotein hormone alpha-subunit and prolactin release by cultured pituitary adenoma cells from acromegalic patients: correlation with GH release.

In-vitro data of pituitary adenoma cells from 28 acromegalic patients were evaluated. In addition to GH, PRL was produced by 16 adenomas (57%) and alpha-subunit by 15 adenomas (54%) while there was a significantly higher incidence of tumours producing PRL and alpha-subunit simultaneously. From 26 pituitary adenomas enough cells were obtained in order to perform secretion studies.

Studies on insulin secretion by monolayer cultures of normal and tumorous human pancreatic cells. Effects of glucose, somatostatin and SMS 201-995.

Recently, somatostatin analogs have been introduced which can be used clinically in the treatment of tumorous or functional hypoglycemia. In the present study we investigated in vitro the regulation, the degree of autonomy and the sensitivity to natural somatostatin and its analog SMS 201-995 of insulin secretion by monolayer cultures of human pancreatic cells obtained from patients with insulinomas and from a newborn with nesidioblastosis. All cultures released insulin upon the addition of dibutyryl-cAMP and calcium, demonstrating their intact viability.

Relationship between growth hormone and somatomedin-C levels in untreated acromegaly, after surgery and radiotherapy and during medical therapy with sandostatin (SMS 201-995).

Several conflicting reports have been published with regard to the relationships between circulating growth hormone (GH), Somatomedin-C (SM-C) levels and clinical activity during different stages of therapy of acromegaly. We did not find a significant correlation between (fasting, post-prandial and mean 24-h) plasma GH and SM-C concentrations in twenty-two untreated acromegalic patients. There was a statistical significant correlation, however, if only the GH levels below 100 micrograms 1(-1) were considered (n = 18 patients, P less than 0.