The purpose of the present study was to explore the relation between the modulation of cerebral blood flow and the latency of hyperbaric oxygen-induced convulsion. There were two parts in this study. First, the effect of acetazolamide on the latency of hyperbaric oxygen-induced convulsion was observed. 32 Sprague-Dawley (SD) rats were randomly divided into four groups: the acetazolamide 200, 20, 2 mg/kg body weight and normal saline (NS) group. The animals were given intraperitoneally acetazolamide or NS, respectively, before being exposed to the pressure of 6 ATA (absolute atmosphere) of pure oxygen. The time from exposure to the onset of seizure (clonic-tonic convulsion) was recorded for each animal according to behavioral observation. Second, the changes in maleic dialdehyde (MDA) and the activity of glutathione peroxidase (GSH-PX) were measured after acetazolamide treatment. 40 SD rats were randomly divided into five groups: NS group, 6 min with NS group, 6 min with acetazolamide group, 16 min with NS group, and 16 min with acetazolamide group. The dose of acetazolamide was 20 mg/kg body weight. After injection of NS or acetazolamide, the animals were subjected to the pressure of 6 ATA of pure oxygen in respect to its time course group. The rats were decapitated and the cortex, hippocampus, and striatum of brains were dissected and homogenized. The content of MDA and the activity of GSH-PX in these tissues were determined. We found that (1) there was a significant difference in the latency of hyperbaric oxygen-induced convulsion between the acetazolamide 200 mg/kg group and the NS control group, as well as between the acetazolamide 20 mg/kg group and the NS control group (P<0.01), whereas there was no significant difference between the NS group and the acetazolamide 2 mg/kg weight group (P>0.05). The latency of these groups were listed as follows: 9.78+/-1.94 min for 200 mg/kg body weight group, 10.92+/-1.68 min for 20 mg/kg body weight group, 24.32+/-4.33 min for 2 mg/kg body weight group and 22.02+/-4.32 min for NS control group. (2) there was no significant difference between all groups in the activity of GSH-PX, though it varied with the oxidation levels. In the cortex and hippocampus, the activity of GSH-PX boosted up at first, but with the progress of the oxidation it was impaired. In the striatum, the activity of GSH-PX increased stepwise with the aggravation of the oxidation. The MDA content in the cortex increased significantly in the group of 6 min with acetazolamide (P<0.01), as well as the group of 16 min with acetazolamide group both in cortex and hippocampus (P<0.01, P<0.05). The MDA content of all groups is correlated with the dose of acetazolamide and the exposure time. These results suggest that acetazolamide which dilates the brain arteriolar obviously shortens the latency of hyperbaric oxygen-induced convulsion, and that acetazolamide dilates the vessels and increases the supply of the oxygen breaking into the brain tissues and aggravates the oxidation. The hyperbaric oxygen-induced convulsion correlates closely with the oxidation injury.
Acetazolamide ; pharmacology ; Animals ; Brain ; pathology ; Hyperbaric Oxygenation ; Male ; Oxidative Stress ; Oxygen ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Seizures ; chemically induced ; physiopathology ; Vasodilator Agents ; pharmacology

AIMTo study the endogenous mechanism for the inhibition of aquaporin-1 expression in rat renal proximal tubule epithelial cells in response to acetazolamide.

METHODSPrimary cultured rat renal proximal tubule epithelia cells were divided into two groups: one was subjected to 1 x 10(-5) mol.L-1 acetazolamide, the other served as normal control. When grown to sub-confluency, the cells were disintegrated to perform isoelectrofocusing electrophoresis in order to find the differential proteins induced by the acetazolamide treatment. The differential proteins were defined by peptide mass fingerprinting technology.

RESULTSTwo differential proteins were found in the cell disintegrant. The pI 3.8 protein was reduced after treatment, which showed 21.4% similarity with the brush border membrane myosin from rat brain and testis, and 27% with glycogen phosphorylase; The pI 5.5 protein was increased on the contrary, with 20% similarity to phosphatidylinositol transfer protein alpha isoform.

CONCLUSIONAcetazolamide inhibited AQP1 expression probably by affecting the expression of pI 3.8 and pI 5.5 proteins.

Acetazolamide ; pharmacology ; Animals ; Aquaporin 1 ; Aquaporins ; antagonists & inhibitors ; metabolism ; Diuretics ; pharmacology ; Epithelial Cells ; metabolism ; Isoelectric Focusing ; Kidney Tubules, Proximal ; cytology ; metabolism ; Male ; Peptide Mapping ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study the selective dilatation effects of iptakalim (Ipt), a novel ATP-sensitive potassium channel opener, on pulmonary arterioles in hypoxic pulmonary hypertensive rat.

METHODSSD male rats were divided into 3 groups, control group, the rest were fed in hypoxic and normobaric environment (O2 10% +/- 0.5%, 8 h/d and 6 d/week) and divided into hypoxia group and hypoxia plus acetazolamide (Acz) group (hypoxic rats were treated with ig acetazolamide (Acz) 80 mg x kg(-1) d(-1)) . After 12 weeks, pulmonary arteriole rings about (197 +/- 4) microm were isolated and the tension of hypoxic pulmonary arterioles pre-contracted by 6 nmol/L endothelin-1 (FT-1) was observed with wire myograph system model (DMT 610 m). The relaxing response of hypoxic pulmonary arterioles induced by different concentration of Ipt were detected and endothelial activity was also tested by acetylcholine.

RESULTS10(-5) mol/L acetylcholine (ACh)-mediated vasodilatation was greatly reduced in the hypoxic group than those in control group (P < 0.01) and there was no significant difference between Acz treatment group and control group (P > 0.05). Ipt at the concentration ranging from 10(-11) mol/L to 10(-4) mol/L, caused dose dependent vasodilation on both hypoxic pulmonary arterioles and Acz treatment group (P > 0.05), but not on normal group.

CONCLUSIONThe endothelial function of pulmonary arterioles was damaged under hypoxic pulmonary hypertensive state, and Ipt showed selective dilatation effects on hypoxic pulmonary arterioles. Acz could improve the dysfunction of endothelial cells induced by hypoxic pulmonary hypertensive state, which didn't affect the selective dilatation effects of Ipt on hypoxic pulmonary arterioles.

Acetazolamide ; Animals ; Arterioles ; drug effects ; physiopathology ; Hypertension, Pulmonary ; physiopathology ; Hypoxia ; physiopathology ; Male ; Propylamines ; pharmacology ; Pulmonary Artery ; drug effects ; physiopathology ; Rats ; Rats, Sprague-Dawley ; Vasodilator Agents ; pharmacology

Hypokalemic periodic paralysis (HOPP) is a rare disease characterized by reversible attacks of muscle weakness accompanied by episodic hypokalemia. Recent molecular work has revealed that the majority of familial HOPP is due to mutations in a skeletal muscle voltage-dependent calcium-channel: the dihydropyridine receptor. We report a 13-yr old boy with HOPP from a family in which 6 members are affected in three generations. Genetic examination identified a nucleotide 3705 C to G mutation in exon 30 of the calcium channel gene, CACNA1S. This mutation predicts a codon change from arginine to glycine at the amino acid position #1239 (R1239G). Among the three known mutations of the CACNA1S gene, the R1239G mutation was rarely reported. This boy and the other family members who did not respond to acetazolamide, showed a marked improvement of the paralytic symptoms after spironolactone treatment.
Acetazolamide/pharmacology ; Adolescent ; Arginine/chemistry ; Calcium Channels/chemistry/*genetics ; Codon ; Exons ; Family Health ; Female ; Glycine/chemistry ; Humans ; Hypokalemia/metabolism ; Hypokalemic Periodic Paralysis/*diagnosis/*genetics ; Korea ; Male ; Muscle, Skeletal/metabolism ; Mutation ; Pedigree ; Protein Structure, Tertiary ; Sequence Analysis, DNA ; Spironolactone/pharmacology