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Biomedical subjects

R M Schimpff

Publications and source records attributed to R M Schimpff.

9 recordsLinked to original sources

[Effect of interleukins and somatomedins on the production of neurotensin by cell line SH-SY5Y derived from human neuroblastoma].

The goal of this study was to investigate the regulation by insulin-like growth factors 1 and 2, and interleukins on the production of neurotensin in the SH-SY5Y cell line derived from a human neuroblastoma. Cultures were performed in RPMI1640 culture medium with heated foetal calf serum 12%. After 24 hrs. of fasting without serum, interleukins-1 alpha, IL-2, IL-4 and insulin-like growth factors 1 and 2 were added. Results showed: 1) A mitogenic effect of ILs (p < 0.001) and of IGFs (p < 0.001). 2) The presence of neurotensin in HCl0.1N cellular extracts (0.06 fmol/micrograms protein). 3) The increase of cellular neurotensin content in the presence of IL-4 (560%), IL-2 (480%), IGF-1 (610%) and IGF-2 (200%). Our results indicate that the human neuroblastoma cell line SH-SY5Y produces neurotensin and that ILs and IGFs act in vitro to modulate this production.

Cell Division

Early paradoxical decrease in serum somatomedin activity following injection of growth hormone.

The early effects have been investigated of an intra-muscular growth hormone injection (6 mg/m2) on serum somatomedin activity in 21 children with growth hormone deficiency and in 5 children with constitutional short stature. In cases of hGH total deficiency, there was an early and significant decrease in SM activity, which reached a minimum level 2 hours after the injection (-34% p less than 0.01). After 24 hours, SM activity increased to +64% above basal levels. In cases of hGH partial deficiency and in short, non-hGH deficient children, no similar early changes were observed. Neither was any correlation found between the variations in SM activity and those in hGH or free fatty acid levels. The unexpected early decrease in SM activity following hGH administration seems to be related to GH deficiency.

Child

Serum somatomedin activity measured as sulphation factor in peripheral, hepatic and renal veins of patients with alcoholic cirrhosis.

Serum somatomedin (SM) activity, measured as sulphation factor on chick embryo cartilage, and growth hormone (GH) levels were measured in peripheral, hepatic and renal veins of 23 patients with a alcoholic cirrhosis. SM activity (mean +/- SEM) was 0.65 +/- 0.05 U/ml in peripheral vein, 0.59 +/- 0.04 U/ml in hepatic vein, and 0.74 +/- 0.07 U/ml in renal vein. Mean GH levels were respectively 2.8, 2.5 and 3.1 ng/ml. Compared to peripheral vein, SM increase in renal vein was 19% (P less than 0.05). Serum SM activity was significantly lower in 13 patients with alcoholic hepatitis associated with cirrhosis than in other 10 patients (P less than 0.02 in hepatic blood and P less than 0.05 in peripheral blood). The decrease of SM activity seems related to cytolysis and hepato-cellular insufficiency. At last, in patients with alcoholic hepatitis, SM activity was lower in the hepatic vein than in the peripheral vein (P less than 0.05). The cause of this difference remains under discussion, no SM inhibitors being found in the serum samples used in this study.

Adult

Serum somatomedin activity depressed after glucagon administration in man.

The variations in serum somatomedin (SM) activity were compared in 14 subjects after glucagon injection (1 mg im), and in 10 controls. A significant decrease in SM activity was observed 30 and 60 min after glucagon (p less than 0.01 to less than 0.001) whereas no significant change was noted in the controls. Analysis of the dose-response curves suggests that this decrease reflects depressed SM concentration. No correlation was found between the variations of growth hormone (GH), cortisol, or fatty acids and those of SM activity. The maximum variations in glycemia, insulin and SM activity occured during the same time interval. These results suggest that glucagon may play some role in the regulation of circulating SM.

Child

The inhibitory effect of hydrocortisone on the chicken embryo cartilage somatomedin assay.

In a study of the effects of hydrocortisone on the embryonic chicken cartilage somatomedin assay, in the absence and in the presence of normal human reference serum (NHRS), it was found that: (1) The basal uptake of 35S into chicken embryo pelvic cartilage was reduced when hydrocortisone hemisuccinate was added to the incubation medium in concentrations ranging from 1.5 to 1.5 X 10(5) ng/ml. There was a correlation between the inhibitory effect and the quantity of hydrocortisone added (r=-0.869; p less than 0.01). (2) The 35S uptake stimulated by 1.25 and 5% serum present in the incubation medium was reduced by hydrocortisone in a final concentration range of 150-1.5 X 10(5) ng/ml incubation medium. The minimal dose was 1,000 times that required to affect the basal 35S uptake. (3) When hydrocortisone was directly added to the NHRS, its interfering effect on the 35S uptake stimulated by 1.25, 5 and 20% of serum in the incubation medium was demonstrable with 5 X 10(5) ng hydrocortisone/ml serum. This concentration exceeded the physiological level of hydrocortisone by a factor of 5,000.

Animals

The liver as a source of somatomedin.

Somatomedin (Sm) activity (measured by [35S] utake in chick embryo cartilage) was determined in serum samples simultaneously drawn from the hepatic vein, portal vein, femoral artery and demoral vein of seventeen anaesthezied normal adult dogs). A pool of human serum was taken as reference (Sm = 1 U/ml). Sm levels in the peripheral vein of dogs were 0.38 +/- 0.03 U/ml). Mean +/- SEM). Sm activity was greater in the hepatic vein (0.48 U/ml) than in the other vessels (0.36, 0.39, 0.38 U/ml), and the paired differences were significant (P less than 0.002 to P less than 0.05). In three dogs which received b-GH (20 IU/day), the Sm levels were significantly increased after nine days in the femoural vein (P less than 0.05) and in the hepatic vein (P less than 0.05). The validity of the assay is discussed; a possible interference of NEFA in the assay is eliminated. The difference of Sm levels between hepatic and portal veins, related to hepatic flow measured in seven of these dogs, indicate an important production of Sm by the liver.

Animals