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Biomedical subjects

E R Froesch

Publications and source records attributed to E R Froesch.

258 records · Page 15Linked to original sources

Differential mood response to natural and synthetic corticosteroids after bilateral adrenalectomy: a case report.

A 48-year-old woman who had had a bilateral adrenalectomy for Cushing's syndrome developed severe psychotic symptoms that were unresponsive to psychotropic drugs as long as she was taking prednisone (PRED) as replacement therapy. However, after she was switched to a regimen of cortisol (CORT) and fludrocortone (FLUD) the psychopathology disappeared. Mechanisms related to the differences in the interaction of natural (e.g. CORT) and synthetic (e.g. PRED) corticosteroids with the central glucocorticoid and mineralocorticoid receptors may explain the different effects upon psychopathology.

Adrenalectomy↗

Growth restoration of insulin-deficient diabetic rats by recombinant human insulin-like growth factor I.

Insulin-like growth factor I (IGF-I) and insulin stem from a common precursor, are structural homologues, act through similar receptors and elicit insulin-like and growth-promoting effects in vitro and in vivo. Serum IGF-I levels are controlled by growth hormone, insulin and nutrition. Insulin-deficient growth-arrested diabetic animals have reduced serum IGF-I levels which are restored towards normal by insulin but not by growth-hormone treatment. Here we show that normal growth of diabetic rate is restored by infusion of recombinant human (rh)IGF-I without normalization of the blood sugar level and that insulin acts via an increase of IGF-I synthesis on growth of diabetic rats. We describe a new mechanism of endocrine control of growth in which IGF-I is the major stimulator at the cellular level. Growth hormone and insulin act mainly by modulating the hepatic synthesis of IGF-I.

Animals↗

Effects of subcutaneous insulin-like growth factor-I infusion on skin microcirculation.

When healthy volunteers were treated with human insulin-like growth factor-I (IGF-I), mild generalized edema often developed. In the present study, the effect of IGF-I on cutaneous capillary permeability and microvascular skin blood flow was investigated using fluorescence videomicroscopy and laser Doppler fluxmetry. Transcapillary diffusion of intravenously injected sodium fluorescein (NaF) was quantitated by videodensitometry in terms of fluorescent light intensities (FLIs) 5, 10, 20, 30, 60, 120, 180 and 300 s after the first appearance of the dye. Laser Doppler fluxmetry was performed at rest (LDFrest) and during postocclusive reactive hyperemia (LDFpeak). Eight healthy subjects (3 women, 5 men; mean age 28 years, range 24-30 years) were investigated. The sensing site was the skin on the right dorsal wrist. Measurements were performed after 4 days of subcutaneous infusion of 0.9% saline (control) and of IGF-I. Mean values for the FLI were significantly higher after IGF-I than after saline infusion (p < 0.05), when the FLIs were expressed in arbitrary units. As percentages of their individual maxima, the differences were significant (p = 0.05) after 60 s (23.6 +/- 6.6% with NaCl and 31.9 +/- 7.6% with IGF-I). LDFrest and LDFpeak tended to be higher after IGF-I treatment without achieving statistical significance (p = 0.176). The mean appearance time of the dye after injection was significantly shorter (p = 0.016) in the IGF-I group than in the control group (32.0 +/- 8.4 s with IGF-I, 42.4 +/- 8.3 s with NaCl).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Comparison of pancreatic human and biosynthetic human insulin with respect to their action on adipocytes and chick embryo fibroblasts.

Biosynthetic human insulin (BHI) was compared to pancreatic human insulin and sperm whale insulin in terms of ability to stimulate incorporation of glucose into isolated rat adipocytes and thymidine into DNA in chick embryo fibroblasts. The human insulins were identical in their effects in both assays. Sperm whale insulin was more potent than the human insulins in stimulating glucose incorporation into rat adipocytes. All three insulins showed identical stimulation of DNA synthesis in the fibroblast assay. That action, however, is mediated via the receptor for insulin-like growth factor (IGF-I). Therefore, both human insulins were evaluated in terms of binding to the IGF-1 receptor in chick embryo fibroblasts. The two human insulins behaved identically (and agreed with previous findings for sperm whale insulin). All insulins, however, were approximately 200-fold less potent than IGF-I itself in this binding assay.

Adipose Tissue↗

[Growth factors with identical insulino-situations : IGF I and II, NSILA and somatomedins (author's transl)].

NSILA consists of two polypeptides of known structure. IGF I and II are close relatives of insulin. 50% of all amino acid residues in the A-and B-region of IGF I and II are situated in identical positions as in the A-and B-chain of insulin. A C-region of 12 and 8 residues respectively connects the A-and B-region in IG FI and II. A D-region of 8 and 6 residues extends the A-region of IGF I and II. 17 of all invariable 19 amino acid residues in the insulin molecules of all known species are also present in IGF. IGF is attached to a carrier protein in serum. The latter inhibits its action on adipose tissue and muscle. Therefore, IGF cannot be measured in serum but, rather, must be dissociated from the binding protein before quantitation. Most tissues appear to have IGF binding sites for which insulin does not compete with the exception of fibroblasts. IGF probably acts via interaction with the IGF receptor, with the exception of adipose tissue where the IGF effect is mediated by the insulin receptor. The concentration of IGF I in serum is under growth hormone control. It is elevated in acromegalics and decreased in pituitary dwarfs and Laron dwarfs. IGF I and II are potent stimulators of cell growth in culture. Their growth stimulating effect in vivo has not yet been unequivocally proven.

Acromegaly↗