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Biomedical subjects

D Kirsch

Publications and source records attributed to D Kirsch.

48 records · Page 3Linked to original sources
PubMed1985

Phorbolesters enhance basal D-glucose transport but inhibit insulin stimulation of D-glucose transport and insulin binding in isolated rat adipocytes.

The C-kinase activating phorbolester TPA (12-O-Tetradecanoyl-beta-phorbol-13-acetate) and PdBu (4-beta-Phorbol-12,13,dibutyrate) stimulated D-glucose transport twofold in isolated rat adipocytes but inhibited high affinity insulin binding and the responsiveness of D-glucose transport to insulin stimulation by about 30%. Phorbolesters have therefore insulin-like effects but antagonize insulin on receptor and postreceptor level.

Adipose Tissue↗
PubMed1984

Protein kinase activity of the insulin receptor from muscle.

The insulin receptor is associated with a protein kinase activity. This has been shown for the receptor of liver, fat, and some other tissues which are not primary targets of insulin action. Here kinase activity is demonstrated for the insulin receptor of rat skeletal and cardiac muscle with similar characteristics. Insulin (10(-7) mol/l) stimulates phosphorylation of the 95-kDa receptor subunit 3- to 18-fold. The effect is detectable at 10(-10) mol/l insulin; the ED50 is approx. 3 X 10(-9) mol/l. The kinase phosphorylates exogenous substrate as well, and it is recovered after immunoprecipitation of the receptor with antireceptor antibody suggesting that kinase activity is intrinsic to the muscle receptor.

Actins↗
PubMed1984

Extrapancreatic action of the sulphonylurea gliquidone: post-receptor effect on insulin-stimulated glycogen synthesis in rat hepatocytes in primary culture.

The effects of a sulphonylurea, gliquidone, on insulin binding and the insulin induced rate of glycogen synthesis, were studied in rat hepatocytes in primary culture. Hepatocytes were cultured for 48 h. During the second 24 h of this period, the hepatocytes were incubated with or without gliquidone (5 mg/l). The binding of 125I-insulin and the insulin stimulation of glycogen synthesis from 14C-glucose were measured. Gliquidone influenced neither insulin binding nor the basal rate of glycogen synthesis, but it did enhance the effect of insulin on glycogen synthesis. Responsiveness was increased by gliquidone at all insulin concentrations used (10-10,000 mU/l); at 1000 mU/l the drug increased glycogen synthesis from 310 to 430% above the basal rate. Half-maximal stimulation was reached in control cells at an insulin concentration of 95 mU/l and in gliquidone-treated cells at 94 mU/l, which indicates unchanged insulin sensitivity. Based on these experiments with cultured rat hepatocytes it appears that the extrapancreatic action of gliquidone is not mediated by an effect on insulin binding.

Animals↗
PubMed1983

Cyclic AMP modulates insulin binding and induces post-receptor insulin resistance of glucose transport in isolated rat adipocytes.

The effect of cAMP on insulin binding and insulin stimulation of glucose transport was investigated in isolated rat adipocytes. Preincubation for 30 min in medium containing 16 mmol/l glucose and either db-cAMP or bromo-cAMP in concentrations of 10(-4)-10(-3) M inhibited high affinity binding of insulin by 15 to 30% and glucose transport by 30 to 50%. Preincubation with IBMX (10(-4)-10(-3) M) reduced insulin binding by 25% and glucose transport by 70%. Closer analysis of these data indicated that preincubation with these compounds caused not only a decrease in insulin binding but also a post-receptor resistance. High intracellular cyclic AMP-levels seem therefore to induce insulin resistance at both receptor and post-receptor levels.

1-Methyl-3-isobutylxanthine↗
PubMedDate not supplied

Effect of the bispyridinium oximes HGG12 and HGG42 and ganglion blocking agents on synaptic transmission and NAD(P)H-fluorescence in the superior cervical ganglion of the rat after Soman poisoning in vitro.

HGG12 and HGG42 are effective therapeutic agents in experimental organophosphate poisoning even after "aging" of the phosphonylated cholinesterase (Hauser, Kirsch, Weger, 1981). In this study we investigated their action in the isolated superior cervical ganglion of the rat (SCGR) after cholinesterase inhibition by Soman (.4 microM). As these two compounds have ganglion blocking properties (Kirsch, Weger, 1981), the action of hexamethonium bromide (C6) and atropine was also investigated and compared to theirs. The typical effects of Soman in the SCGR are a block of ganglionic transmission within 10 sec in a test train of stimuli of 6 Hz, 30 sec, and an increase of the NAD(P)H-fluorescence response up to 3 times the control value. Addition of HGG12 or HGG42 in a concentration of 30-60 microM restores transmission and decreases the metabolic response to almost normal values while obidoxime (60 microM) has no effect at all. C6 (117 microM) and to a lesser degree atropine (30-60 microM) also improve ganglionic transmission and the metabolic response in cholinesterase poisoning. The pattern of amplitudes of APs in a test train of stimuli however is only restored by the HGG compounds and a comparison of equipotent concentrations (50% inhibition of AP in unpoisoned ganglia) shows that HGG12 has the best effects in Soman poisoned SCGR. The superiority of HGG12 can be explained by an inhibitory action of HGG12 on both nicotinic and muscarinic ganglionic receptors.

Action Potentials↗
PubMedDate not supplied

A comparison of the success rates of resident and attending strabismus surgery.

Residency training involves surgery by resident surgeons at various levels of experience and proficiency, supervised by an experienced attending physician. We reviewed the results of strabismus surgery performed at four institutions with two residency training programs. Five hundred twenty-two cases with follow up greater than 6 weeks were evaluated. These cases included 315 attending procedures and 207 resident procedures under direct attending supervision. Success was defined as a strabismic deviation of 8 prism diopters or less. Average postoperative follow-up was 57 weeks and did not differ between groups. There was no statistical difference between the resident success rate of 58% (121/207) and the attending success rate of 69% (217/315) after adjusting for population differences. The average final deviation of the patients postoperatively was 7 delta for the attending group and 10 delta for the resident group. Amblyopia was significantly more frequent in the resident cases (P < .001). Adjustable sutures were used significantly more often in attending cases (P < .0001). This study supports the premise that resident strabismus surgery is as successful as attending surgery.

Adolescent↗