Differences in endocochlear potentials in response to anoxia in maturing and mature guinea pigs

1990 ◽  
Vol 248 (1) ◽  
pp. 8-10 ◽  
Author(s):  
M. Ohmura ◽  
E. Yamamoto
Keyword(s):  
Guinea Pigs ◽  
Endocochlear Potentials

Lack of Effect of Carbonic Anhydrase Inhibition on Direct Measurements of Endolymph Bicarbonate

1989 ◽  
Vol 98 (3) ◽  
pp. 209-212
Author(s):  
John H. Isaacs ◽  
Gerald E. Merwin ◽  
Ness Pessah ◽  
Thomas H. Maren
Keyword(s):  
Standard Deviation ◽  
Carbonic Anhydrase ◽  
Guinea Pigs ◽  
Carbonic Anhydrase Inhibitor ◽  
Sodium Potassium ◽  
Plasma Bicarbonate ◽  
The Past ◽  
Direct Measurements ◽  
Carbonic Anhydrase Inhibition ◽  
Endocochlear Potentials

In the past, sodium, potassium, and chloride have been measured in endolymph directly, but bicarbonate has been measured only indirectly. We sampled endolymph directly while monitoring endocochlear potentials in normal and methazolamide-treated guinea pigs. Bicarbonate was determined in samples by use of a method that depends on reduction of NADH to NAD linked to malate formation from oxaloacetate. In 11 normal animals, the bicarbonate in endolymph was 20.2 m M ± 4.4 m M (mean ± standard deviation); in six of these, plasma bicarbonate was 23.1 m M ± 3.5 m M. Nine animals treated with methazolamide (carbonic anhydrase inhibitor) had an endolymph bicarbonate of 19.5 m M ± 3.9 m M; plasma bicarbonate in five of these was 25 m M ± 3.2 m M. Carbonic anhydrase inhibition did not significantly affect endolymphatic bicarbonate levels.

Carbonic anhydrase in the generation of cochlear potentials

1978 ◽  
Vol 235 (4) ◽  
pp. F317-F320 ◽  
Author(s):  
J. Prazma
Keyword(s):  
Carbonic Anhydrase ◽  
Guinea Pigs ◽  
Round Window ◽  
Silver Wire ◽  
Cochlear Microphonics ◽  
Wire Electrode ◽  
Cochlear Potentials ◽  
Endocochlear Potentials ◽  
First Time ◽  
Second Period

The experiments on 18 guinea pigs were divided into two groups and each group was arranged in such a way that the effect of hypercapnia (generated by breathing 10% CO2-90% O2) was investigated with and without inhibition of carbonic anhydrase by methazolamide, 25 mg/kg, in the first group and acetazolamide, 50 mg/kg, in the second group, administered intravenously. The endocochlear potentials (EP) and endocochlear PO2 were recorded by microelectrodes introduced into the scala media, and cochlear microphonics (CM) were monitored by a silver-wire electrode from the round window. In the first exposure to hypercapnia (20-40 min) EP increased about + 6 mV. At the same time CM decreased; the reason for this is not yet known. During the second period of hypercapnia (80-100 min) when carbonic anhydrase was inhibited with methazolamide and acetazolamide, EP did not elevate as during the first period when carbonic anhydrase was not inhibited. In this work, under specific conditions, it was observed for the first time that carbonic anhydrase affects the generation of EP.

Investigation of the relaxant effects of propofol on ovalbumin-induced asthma in guinea pigs

2006 ◽  
pp. 1
Author(s):  
I. Bagcivan ◽  
O. Cevit ◽  
M. K. Yildirim ◽  
S. Gursoy ◽  
S. Yildirim ◽  
...  
Keyword(s):  
Guinea Pigs

Hepatocyte Alterations in Guinea Pigs FED Polychlorinated Biphenyls (PCBs), Dibenzodioxins (PCDD), AND DIBENZOFURANS (PCDF)

1982 ◽  
Vol 40 ◽  
pp. 56-57
Author(s):  
J. N. Turner ◽  
D. N. Collins
Keyword(s):  
Guinea Pigs ◽  
Room Temperature ◽  
Dose Group ◽  
Methyl Cellulose ◽  
Uranyl Acetate ◽  
Target Organ ◽  
Office Building ◽  
Lead Citrate ◽  
Control Groups ◽  
Cooling Fluid

A fire involving an electric service transformer and its cooling fluid, a mixture of PCBs and chlorinated benzenes, contaminated an office building with a fine soot. Chemical analysis showed PCDDs and PCDFs including the highly toxic tetra isomers. Guinea pigs were chosen as an experimental animal to test the soot's toxicity because of their sensitivity to these compounds, and the liver was examined because it is a target organ. The soot was suspended in 0.75% methyl cellulose and administered in a single dose by gavage at levels of 1,10,100, and 500mgm soot/kgm body weight. Each dose group was composed of 6 males and 6 females. Control groups included 12 (6 male, 6 female) animals fed activated carbon in methyl cellulose, 6 males fed methyl cellulose, and 16 males and 10 females untreated. The guinea pigs were sacrificed at 42 days by suffocation in CO2. Liver samples were immediately immersed and minced in 2% gluteraldehyde in cacadylate buffer at pH 7.4 and 4°C. After overnight fixation, samples were postfixed in 1% OsO4 in cacodylate for 1 hr at room temperature, embedded in epon, sectioned and stained with uranyl acetate and lead citrate.

Glycogen in guinea pig neutrophils: Ultrastructural study of neutrophils at the intradermal site of BCG injection

1983 ◽  
Vol 41 ◽  
pp. 726-727
Author(s):  
Corazon D. Bucana
Keyword(s):  
Bone Marrow ◽  
Guinea Pig ◽  
Electron Density ◽  
Peritoneal Cavity ◽  
Ultrastructural Study ◽  
Guinea Pigs ◽  
Random Distribution ◽  
Glycogen Content ◽  
Polymorphonuclear Neutrophils ◽  
Ultrastructural Studies

In the circulating blood of man and guinea pigs, glycogen occurs primarily in polymorphonuclear neutrophils and platelets. The amount of glycogen in neutrophils increases with time after the cells leave the bone marrow, and the distribution of glycogen in neutrophils changes from an apparently random distribution to large clumps when these cells move out of the circulation to the site of inflammation in the peritoneal cavity. The objective of this study was to further investigate changes in glycogen content and distribution in neutrophils. I chose an intradermal site because it allows study of neutrophils at various stages of extravasation.Initially, osmium ferrocyanide and osmium ferricyanide were used to fix glycogen in the neutrophils for ultrastructural studies. My findings confirmed previous reports that showed that glycogen is well preserved by both these fixatives and that osmium ferricyanide protects glycogen from solubilization by uranyl acetate.I found that osmium ferrocyanide similarly protected glycogen. My studies showed, however, that the electron density of mitochondria and other cytoplasmic organelles was lower in samples fixed with osmium ferrocyanide than in samples fixed with osmium ferricyanide.

Densitometric Identification of Primitive Erythroblasts After Reaction With Diaminobenzidine

1973 ◽  
Vol 31 ◽  
pp. 328-329
Author(s):  
John A. Trotter
Keyword(s):  
Red Blood Cells ◽  
Analytical Method ◽  
Blood Cells ◽  
Guinea Pigs ◽  
Specific Protein ◽  
Visual Examination ◽  
Hemoglobin Synthesis ◽  
Peroxidatic Activity ◽  
Small Density

Hemoglobin is the specific protein of red blood cells. Those cells in which hemoglobin synthesis is initiated are the earliest cells that can presently be considered to be committed to erythropoiesis. In order to identify such early cells electron microscopically, we have made use of the peroxidatic activity of hemoglobin by reacting the marrow of erythropoietically stimulated guinea pigs with diaminobenzidine (DAB). The reaction product appeared as a diffuse and amorphous electron opacity throughout the cytoplasm of reactive cells. The detection of small density increases of such a diffuse nature required an analytical method more sensitive and reliable than the visual examination of micrographs. A procedure was therefore devised for the evaluation of micrographs (negatives) with a densitometer (Weston Photographic Analyzer).

Annulate lamellae in the Sertoli cells of guinea pig testis after unilateral torsion of the spermatic cord

1984 ◽  
Vol 42 ◽  
pp. 196-197
Author(s):  
J. Chakraborty ◽  
A. P. Sinha Hikim ◽  
J. S. Jhunjhunwala
Keyword(s):  
Sertoli Cells ◽  
Guinea Pigs ◽  
Spermatic Cord ◽  
Present Report ◽  
Cell Types ◽  
Annulate Lamellae ◽  
Spermatogenic Cells ◽  
Electron Microscopic ◽  
Structural Details ◽  
First Time

Although the presence of annulate lamellae was noted in many cell types, including the rat spermatogenic cells, this structure was never reported in the Sertoli cells of any rodent species. The present report is based on a part of our project on the effect of torsion of the spermatic cord to the contralateral testis. This paper describes for the first time, the fine structural details of the annulate lamellae in the Sertoli cells of damaged testis from guinea pigs.One side of the spermatic cord of each of six Hartly strain adult guinea pigs was surgically twisted (540°) under pentobarbital anesthesia (1). Four months after induction of torsion, animals were sacrificed, testes were excised and processed for the light and electron microscopic investigations. In the damaged testis, the majority of seminiferous tubule contained a layer of Sertoli cells with occasional spermatogonia (Fig. 1). Nuclei of these Sertoli cells were highly pleomorphic and contained small chromatinic clumps adjacent to the inner aspect of the nuclear envelope (Fig. 2).

Alterations in Ultrastructure of Skeletal Muscle From Newborn Guinea Pigs Following in Utero Exposure to Ethanol

1985 ◽  
Vol 43 ◽  
pp. 686-687
Author(s):  
C. Uphoff ◽  
C. Nyquist-Battie ◽  
T.B. Cole
Keyword(s):  
Skeletal Muscle ◽  
Guinea Pigs ◽  
Muscle Development ◽  
In Utero ◽  
Ethanol Exposure ◽  
Prenatally Exposed ◽  
Chronic Alcoholic ◽  
Test Kit ◽  
Food And Water Intake ◽  
Post Intubation

Ultrastructural alterations of skeletal muscle have been observed in adult chronic alcoholic patients. However, no such study has been performed on individuals prenatally exposed to ethanol. In order to determine if ethanol exposure in utero in the latter stages of muscle development was deleterious, skeletal muscle was obtained from newborn guinea pigs treated in the following manner. Six Hartly strain pregnant guinea pigs were randomly assigned to either the ethanol or the pair-intubated groups. Twice daily the 3 ethanol-treated animals were intubated with Ensure (Ross Laboratories) liquid diet containing 30% ethanol (6g/Kg pre-pregnant body weight per day) from day 35 of gestation until parturition at day 70±1 day. Serum ethanol levels were determined at 1 hour post-intubation by the Sigma alcohol test kit. For pair-intubation the Ensure diet contained sucrose substituted isocalorically for ethanol. Both food and water intake were monitored.

The effect of lead exposure on DCX positive cells in layer II of adult guinea pigs neocortex

2010 ◽  
Vol 34 (8) ◽  
pp. S18-S18
Author(s):  
Kun Xiong ◽  
Kai Huang ◽  
Lei Shang ◽  
Hui Wang ◽  
Xiao‑xin Yan ◽  
...  
Keyword(s):  
Lead Exposure ◽  
Guinea Pigs

Pulmonary surfactant given prophylactically alleviates an asthma attack in guinea-pigs

1996 ◽  
Vol 26 (3) ◽  
pp. 270-275 ◽  
Author(s):  
M. LIU ◽  
L. WANG ◽  
E. LI ◽  
G. ENHORNING
Keyword(s):  
Guinea Pigs ◽  
Pulmonary Surfactant ◽  
Asthma Attack
Sign in / Sign up

Export Citation Format

Share Document