Postischemic ATP levels predict hepatic function 24 hours following ischemia in the rat

Hepatic function was assessed by the aminopyrine breath test (ABT) in male Sprague Dawley rats 24 h after partial hepatic ischemia. ABT decreased progressively to 26.3 (p less than 0.05) and 19.7% of dose (p less than 0.05) after 90 and 120 min of ischemia, respectively. ABT at 24 h after injury was correlated to the concentration of ATP in the ischemic lobes 1 h after the onset of reperfusion (r2 = 0.971) but not to ALT activity in plasma at 1 h (r2 = 0.391). We conclude that postischemic ATP levels are a better index of subsequent hepatic function than ALT.     

Postischemic ATP levels predict hepatic function 24 hours following ischemia in the rat

Summary Hepatic function was assessed by the aminopyrine breath test (ABT) in male Sprague Dawley rats 24 h after partial hepatic ischemia. ABT decreased progressively to 26.3 (p<0.05) and 19.7% of dose (p<0.05) after 90 and 120 min of ischemia, respectively. ABT at 24 h after injury was correlated to the concentration of ATP in the ischemic lobes 1 h after the onset of reperfusion (r²=0.971) but not to ALT activity in plasma at 1 h (r²=0.391). We conclude that postischemic ATP levels are a better index of subsequent hepatic function than ALT.     

Serum thymic factor as a radioprotective agent promoting survival after X-irradiation

Summary Serum thymic factor (FTS, zinc-free thymulin) protected mice from death after whole-body X-irradiation. It was significantly radioprotective even when administered after irradiation, but it was more effective when administered both before and after irradiation. The protective effect appears to be due to the enhancement of hematologic recovery in the animals.     

Serum thymic factor as a radioprotective agent promoting survival after X-irradiation

Serum thymic factor (FTS, zinc-free thymulin) protected mice from death after whole-body X-irradiation. It was significantly radioprotective even when administered after irradiation, but it was more effective when administered both before and after irradiation. The protective effect appears to be due to the enhancement of hematologic recovery in the animals.     

Radioprotective effect of a protein free parathyroid extract on the mitotic index of rat bone marrow cells.

The protective efficacy of an orally administered bovine protein-free parathyroid extract (PF-PTE) was studied on rat bone marrow cells in vivo with the mitotic index after 850 R irradiation. A remarkable decrease was found in the mitotic activity of bone marrow cells after irradiation in the non-protected animals. However, in the animals treated with PF-PTE after irradiation, a significantly smaller decrease and a faster recovery were found in the mitotic activity of the bone marrow cells.     

Effect of repeated electroconvulsive shock on plasma noradrenaline and adrenaline in man

Summary The concentration of noradrenaline (NA) and of adrenaline (A) in plasma was measured before and 3, 30 and 60 min after single and repeated electroconvulsive shocks (ECS). Single ECS resulted in an activation of the sympathoadrenal medullary system; however, after the treatment had been repeated 4 times there was evidence of a diminished response of the peripheral sympathetic nervous system in comparison to the response to the first ECS.     

Radioprotective effect of a protein free parathyroid extract on the mitotic index of rat bone marrow cells

Summary The protective efficacy of an orally administered bovine protein-free parathyroid extract (PF-PTE) was studied on rat bone marrow cells in vivo with the mitotic index after 850 R irradiation. A remarkable decrease was found in the mitotic activity of bone marrow cells after irradiation in the non-protected animals. However, in the animals treated with PF-PTE after irradiation, a significantly smaller decrease and a faster recovery were found in the mitotic activity of the bone marrow cells.     

Nonspecific reaction of a thiol: protein disulfide oxidoreductase with the disulfide bonds of insulin

A thiol: protein disulfide oxidoreductase from bovine liver was isolated after separation from protein disulfide isomerase. The enzyme, after activation (reduction) with glutathione, was reacted with stoichiometric amounts of insulin and the sulfhydryl groups of the partially reduced hormone were labeled with iodo (l-14C)acetamide. After separation of the insulin chains, the radioactivity was found in both the peptides, with a ratio A-chain/B-chain equal to 2/1.     

Nonspecific reaction of a thiol:Protein disulfide oxidoreductase with the disulfide bonds of insulin

Summary A thiol:protein disulfide oxidoreductase from bovine liver was isolated after separation from protein disulfide isomerase. The enzyme, after activation (reduction) with glutathione, was reacted with stoichiometric amounts of insulin and the sulfhydryl groups of the partially reduced hormone were labeled with iodo (l-¹⁴C)acetamide. After separation of the insulin chains, the radioactivity was found in both the peptides, with a ratio A-chain/B-chain equal to 2/1.     

‘Classical’ and ‘new’ diabetogens—comparison of their effects on isolated rat pancreatic islets in vitro

This study compares functional and morphological alterations caused by application of alloxan, streptozotocin, xanthine oxidase/hypoxanthine (generation of reactive oxygen species), or S-nitroso-N-acetyl-D,L-penicillamine (SNAP, liberation of nitric oxide) to isolated rat pancreatic islets in vitro. In perifusion experiments, membrane leakage—detected by non-stimulated insulin release—was found after application of all drugs, but showed a substance-specific time pattern. Twenty-four hours after application of the classical diabetogens (alloxan or streptozotocin), potassium chloride- and glucose-stimulated insulin secretion were markedly reduced, while a persistent reduction was observed neither after exposure to xanthine oxidase/hypoxanthine, nor to SNAP. Morphological analysis of the islets revealed that nearly all β-cells were destroyed following alloxan or streptozotocin treatment, while the majority of β-cells were configured regularly after application of xanthine oxidase/hypoxanthine or SNAP. Necrotic cells found after xanthine oxidase/hypoxanthine usually differed in morphology from those observed after application of the classical diabetogens. While the former cells were characterised by swollen nuclei, the latter had shrunken nuclei with irregular condensed chromatin. Apoptosis was found only following nitric oxide exposure. Due to these differences, it seems unlikely that alloxan, streptozotocin, xanthine oxidase/hypoxanthine, and nitric oxide have a common major feature in their toxic action. Received 16 September 1999; received after revision 15 November 1999; accepted 26 November 1999     

«Colony-stimulating activity» im Serum und der Milz nach Rauscher Virusinfektion

Summary Colony-stimulating activity (CSA) of serum and spleen was studied in CBA/J mice 1–5 days after Rauscher virus infection, using the agar culture system with normal mouse bone marrow cells as target cells. A sharp increase of CSA was observed with a peak after 2 days in both sites; after 5 days control levels are reached.

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Mit Unterstützung der Deutschen Forschungsgemeinschaft (SFB 112, Zellsystemphysiologie).     

Serum activity inhibiting specific simian virus 40-induced transplantation resistance and its correlation with primary SV40 tumors appearance in hamsters.

Using the modified technique of transplantation test, ITR serum activity was found in most (14 out of 21) individual hamster sera obtained during the latent period of primary SV40 carcinogenesis (60 days after virus infection when newborn). On the other hand, as a rule, no ITR activity was observed in the sera of the same hamsters after tumor appearance and during their growth. ITR activity rapidly disappeared from sera of hamsters neonatally infected with SV40 after their successful immunization with the same virus during the latent period. There appears to be a correlation between the presence of ITR serum factor during the latent period and the subsequent primary SV40 tumor appearance in hamsters.     

Calcitonin: Effect on protein synthesis in different rat tissues

Summary Protein synthesis was inhibited in the pancreas whereas it was enhanced in the kidney and intestine (jejunumileum) after a single injection of porcine calcitonin (20 MRC units/kg b.wt). The incorporation of [³H]leucine into total protein in the brain, heart, liver and stomach did not change after the hormone treatment.Acknowledgment. This work has been achieved at the Institute of Medical Biochemistry, University of Aarhus, Aarhus, Denmark.     

Effect of lesions of the locus coeruleus complex on the circadian rhythm of plasma corticosterone in the mouse.

An apparently transient elevation of basal morning (08.00 h) plasma corticosterone levels in male mice was found 48 h after bilateral electrolytic lesions of the brainstem locus coeruleus complex but was not observed 6 weeks after lesioning.     

PTEN–GSK3β–MOB1 axis controls neurite outgrowth in vitro and in vivo

Mps One binder 1 (MOB1) is a core component of NDR/LATS kinase and a positive regulator of the Hippo signaling pathway. However, its role in neurite outgrowth still remains to be clarified. Here, we confirmed, for the first time, that MOB1 promoted neurite outgrowth and was involved in functional recovery after spinal cord injury (SCI) in mice. Mechanistically, we found that MOB1 stability was regulated by the PTEN–GSK3β axis. The MOB1 protein was significantly up-regulated in PTEN-knockdown neuronal cells. This effect was dependent on the lipid phosphatase activity of PTEN. Moreover, MOB1 was found to be a novel substrate for GSK3β that is phosphorylated on serine 146 and degraded via the ubiquitin–proteasome system (UPS). Finally, in vivo lentiviral-mediated silencing of PTEN promoted neurite outgrowth and functional recovery after SCI and this effect was reversed by down-regulation of MOB1. Taken together, this study provided mechanistic insight into how MOB1 acts as a novel and a necessary regulator in PTEN–GSK3β axis that controls neurite outgrowth after SCI.     

Gap junctional intercellular communication of cultured rat liver parenchymal cells is stabilized by epithelial cells and their isolated plasma membranes

The gap junctional intercellular communication (GJIC) determined by measuring dye coupling with Lucifer yellow, decreased within 3 d from 66% to 28% in monocultures of rat liver parenchymal cells. Coculturing of the parenchymal cells with a nonparenchymal epithelial cell line from rat liver resulted in increased and stabilized intercellular communication (83% after 3 d). The presence of isolated plasma membrane vesicles of the nonparenchymal epithelial cells also stabilized the intercellular communication between the liver parenchymal cells (70% after 3 d). When liver parenchymal cells were cocultured with a rat liver fibroblast cell line the gap junctional communication between the parenchymal cells was not stabilized (43% after 3 d), and isolated plasma membrane vesicles of the fibroblast were also unable to support the GJIC in parenchymal cells (35% after 3 d). It is concluded that plasma membrane constituents of the nonparenchymal epithelial cells were responsible for the stabilization of the GJIC between parenchymal cells. A heterotypic gap junctional communication between parenchymal and nonparenchymal cells was not observed.     

Ethanol diminishes the toxicity of the mushroom Amanita phalloides

Survival of mice after lethal doses of a lyophilizate from Amanita phalloides ('death cap') was markedly increased by single doses of ethanol applied 30 min before or 5 min after the mushroom. Hepatic histopathological damage (confluent necrosis) was largely prevented. Acute, but not chronic, consumption of ethanol may thus influence favorably the outcome of death cap poisoning and should be taken into consideration in the evaluation of therapeutic measures.     

Changes in binding of JH-III in hemolymph of adult femaleLocusta migratoria

Summary Hemolymph from adult femaleLocusta migratoria migratorioides was analyzed for binding of juvenile hormone III (JH-III) after allatectomy and transection of thenervus corporis allati 1 (NCA-I). These operations did not affect the apparent dissociation constant of the binding (Kd=3.3 10^–8 M). The concentration of binding sites exhibited fluctuations in relation to age and type of operation: an increased concentration of binding sites in females with disconnected corpora allata and a decreased concentration in allatectomized females. The changes in concentration of binding sites was not due to differences in water content or hemolymph volume in operated animals. The hemolymph protein concentration was reduced after NCA-I transection and even more after allatectomy. However, variations in protein concentration did not correlate with changes in concentration of JH-III binding sites. The changes in binding site concentration were related to changes in JH-titer.     

Frühe Stadien der Erholung bei bestrahlten ratten und Mäusen

Summary A split dose experiment was performed in 12-, 24- or 32-day-old Wistar rats. About 4000 animals were used. The first dose given was 200 R whole-body X-irradiation in the 2 younger groups, and 260 R in the oldest group. At intervals from 6–48 h after the first, a second irradiation was given in order to estimate the LD50(30). No recovery was seen in terms of the LD50(30) differences between preirradiated and normal animals 6 h after the first dose. At the 12 h interval marked recovery was found in all 3 age groups, but less recovery was apparent at the later intervals.     

Promotion of epithelial keratinization by N-methyl-N'-nitro-N-nitrosoguanidine in rat forestomach in organ culture.

The effect of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) on epithelial differentiation of fetal rat forestomach was investigated in organ culture. When forestomach tissues removed from 16.5-day fetuses were treated with 5 microgram and 3 microgram of MNNG per ml for 1 h, epithelial keratinization was observed after 4 and 5 days, respectively, whereas it occurred after 6 days in control cultures. A clear dose-response relationship was found in the promotion of epithelial keratinization by MNNG.