potassium-cyanate and sodium-cyanate

It is difficult task to measure precisely the toxic effect of beta-amyloid (Aβ 1-42) peptides and also the protective effect of novel drug candidates against Aβ-peptides. The widely used MTT-assay in cell lines or primary cell cultures could be insensitive against Aβ-peptides. We describe here an easy and relevant method for testing Aβ 1-42 toxicity on acute hippocampal slices derived from rat. Brain slice viability in different conditions was measured using MTT and LDH assays. The concomitant use of these two assays can give detailed and relevant results on the toxic effect of Aβ 1-42 in oxygen-glucose deprived (OGD) acute brain slice model. Both assays are capable of quantifying tissue viability by measuring optical density (OD). We found that simultaneous application of OGD and Aβ 1-42 treatment induced a more intensive decrease in hippocampal slice viability than their separate effects. The use of MTT and LDH assay for quantifying brain slice viability proved to be an easy ex vivo method for investigating Aβ toxicity. Testing brain slices is more relevant in Alzheimer's Disease research than using in vitro cell cultures, due to maintenance of the three dimensional cellular network, the cell variability and intact cell connections.

Topics: Amyloid beta-Peptides; Analysis of Variance; Animals; Animals, Newborn; Cyanates; Glucose; Hippocampus; Hydrogen Peroxide; Hypoxia; In Vitro Techniques; L-Lactate Dehydrogenase; Male; Peptide Fragments; Rats; Rats, Wistar; Tetrazolium Salts; Thiazoles

The physiological role of carbonic anhydrase III in slow-twitch skeletal muscle was investigated using isolated mouse soleus (N = 30) contracting once every 1.7 min for 75 min in Krebs-Henseleit solution gassed with either 95% oxygen - 5% carbon dioxide (normocapnia) or 90% oxygen - 10% carbon dioxide (hypercapnia). Each contraction was 500 ms in duration at 50 Hz. When muscles contracted in normocapnic solution (pH 7.42), the developed tension decreased an average of 6.1 +/- 0.8% over 25 min. For the next 50 min, 15 muscles remained normocapnic, while the remainder contracted in hypercapnic solution (pH 7.20). Tension decreased significantly more with hypercapnia. For the last 25 min, both normocapnic and hypercapnic muscles were divided into three treatment groups (N = 5). One group continued in the same environment, while acetazolamide (final concentration of 10(-5) M) was added to the bath of the second and sodium cyanate (final concentration of 10(-5) M) was added to the bath of the third group. Acetazolamide had no effect on tension in either carbon dioxide environment. Sodium cyanate significantly decreased tension from the hypercapnic control but had no effect in normocapnia. Thus carbonic anhydrase III inhibition with sodium cyanate increased the effect of hypercapnia implying that carbonic anhydrase III assists in the regulation of free hydrogen ion concentration in slow-twitch skeletal muscle.

Topics: Acetazolamide; Animals; Carbon Dioxide; Carbonic Anhydrase Inhibitors; Carbonic Anhydrases; Cyanates; Hypercapnia; In Vitro Techniques; Mice; Muscle Contraction; Muscles