Development of a primary culture system of rat kidney cortical cells to evaluate the nephrotoxicity of xenobiotics.

A method has been developed for preparing primary monolayer cultures of postnatal rat kidney cortical epithelial cells. These cultures maintained differentiated cell functions and epithelial-like morphology for several days in culture. The presence of alkaline phosphatase and maltase was used to confirm the presence of cells from the renal cortex.

Cytotoxicity of ethanol in primary cultures of rat midbrain neurons.

Primary cultures of midbrain neurons were obtained from 15-day-old rat fetuses. Neuron cultures were exposed to ethanol (27 mM, 43 mM and 120 mM) for 24 h and evaluated by light microscopy, a viability measure, and protein content. Ethanol concentrations of 43 and 120 mM appeared to affect the cultures both in terms of cell viability and protein.

Oral toxicity of carbon tetrachloride: acute, subacute, and subchronic studies in rats.

This investigation was conducted to characterize the acute, subacute, and subchronic toxic potency of ingested carbon tetrachloride (CCl4). In the first acute and subacute toxicity study, male Sprague-Dawley rats of 300-350 g were gavaged with 0, 20, 40, or 80 mg CCl4/kg once daily for 5 consecutive days, rested for 2 days, and dosed once daily for 4 additional days. Rats of 200-250 g were gavaged with 0, 20, 80, or 160 mg CCl4/kg according to the same dosage regimen in the second acute and subacute study.

Role of glutathione depletion in the cytotoxicity of acetaminophen in a primary culture system of rat hepatocytes.

A primary culture system of postnatal rat hepatocytes was utilized to study the cytotoxicity of acetaminophen and the toxicological significance of glutathione (GSH) depletion. The relative time of onset and magnitude of GSH depletion, lipid peroxidation and cytotoxicity were contrasted in order to gain insight into their interrelationships. Exposure of the hepatocytes to acetaminophen resulted in time- and dose-dependent depletion of cellular GSH.

Erythromycin estolate-induced toxicity in cultured rat hepatocytes.

Primary cultures of rat hepatocytes were exposed to several concentrations of erythromycin estolate (EE). Hepatotoxicity was evaluated using lactate dehydrogenase (LDH) leakage and morphometric analysis of representative populations of cells examined optically. Results of the two techniques provided parallel information: cells exposed to the higher concentrations of EE had significantly greater LDH release and higher percentages of morphologically damaged cells.

An in vitro approach to the study of target organ toxicity of drugs and chemicals.

A major goal of our laboratory has been the development of primary culture systems that retain differentiated functions and responses characteristic of intact tissues in vivo. Specifically, we have developed cellular models of primary cultures of rat heart, liver, and kidney cells to explore the mechanisms by which drugs or chemicals may be toxic to key organs of the body and to develop new techniques by which xenobiotics may be evaluated or identified as potential toxicants to living systems. The purpose of this paper is to describe our rationale and approach to the study of target organ toxicology with in vitro cellular systems.

Ethanol toxicity in primary cultures of rat myocardial cells.

The potential cardiotoxicity of ethanol (EtOH) was evaluated in primary cultures of rat myocardial cells. EtOH cardiotoxicity was assessed in the cells on the basis of cell morphology, lactate dehydrogenase (LDH) leakage, succinate dehydrogenase (SDH) activity, and beating rates. Cells were treated with EtOH at concentrations of 600, 800, and 1000 mg% for duration of 1, 4, and 24 h and then evaluated for cardiotoxicity.

Effects of cadmium and calcium on the fluidity of plasma membranes.

The fluidity of plasma membranes was assessed by steady-state fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH), a fluorescent probe. The presence of increasing concentrations of calcium (Ca) (0.5-4 mM), cadmium (Cd) (50-500 microM), or both decreased the motional freedom of the fluorescent probe molecules in plasma membranes derived from both human erythrocytes and rat hepatocytes.

Relative toxicities of several nonsteroidal antiinflammatory compounds in primary cultures of rat hepatocytes.

Primary cultures of intact, functional heptocytes were used to compare the relative toxicity of four nonsteroid antiinflammatory agents (NSAID)--benoxaprofen, orpanoxin, aspirin, and ibuprofen--with that of indomethacin. The relative toxicity of these compounds was evaluated on the basis of the release of lactate dehydrogenase, levels of urea (an indicator of a liver specific function), viability (based on dye exclusion), and morphology after a 12-h exposure to concentrations ranging from 0 to 1000 microM. Evaluation of the data obtained from these three parameters enabled us to rank these compounds from toxic to nontoxic, in decreasing order to toxicity: indomethacin greater than benoxaprofen greater than ibuprofen greater than or equal to aspirin greater than or equal to orpanoxin.

Comparison of dantrolene sodium with erythromycin estolate using primary cultures of rat hepatocytes.

Using primary cultures of parenchymal hepatocytes as a model system, the cytotoxic potential of dantrolene sodium (DS) was compared with that of erythromycin estolate (EE)--a known hepatotoxin. Parallel morphological and functional comparisons were made, following 4-, 8-, or 24-h exposures of hepatocyte cultures, using phase contrast microscopy and lactate dehydrogenase (LDH) leakage, respectively. Four-hour exposures of cultures to rather low concentrations of EE (i.

Calcium amelioration of cadmium-induced cytotoxicity in cultured rat hepatocytes.

Parenchymal hepatocytes from neonatal rats were isolated, cultured about 24 h, exposed to cadmium with or without calcium, and processed for scanning electron microscopy. To assess the severity of cadmium-induced changes, exposed hepatocytes were categorized based upon the extent of morphological damage. Differences in surface blebbing, alterations in microvilli, variations in the degree of swelling, and changes in cell shape were used to categorize the severity of cell damage.

Cadmium-induced hepatotoxicity in cultured rat hepatocytes as evaluated by morphometric analysis.

Freshly isolated hepatocytes from neonatal rats were cultured for approximately 24 h; incubated for 5, 30, or 60 min in solutions containing 0, 50, 100, or 200 microM cadmium; embedded in plastic; and sectioned for optical microscopy. The extent of cadmium-induced hepatotoxicity was evaluated by double-blind morphometric analysis (a geometricostatistical processing of two-dimensional data for the collection of three-dimensional information) whereby hepatocytes were classified on the basis of the severity of morphologic damage at the optical level. Both time and concentration effects were studied.

Cell injury of cultured rat myocardial cells after reoxygenation of hypoxic cultures in the presence and absence of calcium.

Primary cultures of rat myocytes were deprived of oxygen (approximately 5 mm Hg, pO2) for 2 h in the presence or absence of calcium and were subsequently incubated for different time periods under normoxic (approximately 120 mm Hg, pO2) conditions. Myocyte calcium content was determined at the end of the oxygen-free period and after repletion of oxygen. Lactate dehydrogenase (LDH) release from the cells into the medium was used as an index of cell injury.

Effects of cardioactive drugs on the beating activity of myocardial cell cultures isolated from offspring of trained and untrained pregnant rats.

Primary cultures of beating myocardial cells were obtained from 5-d-old offspring of trained (T) and untrained (UT), pregnant, Sprague-Dawley rats. The myocardial cells from the T and UT groups were evaluated for their beating responses to three cardioactive drugs: verapamil (V), isoproterenol (ISO), and propranolol (PRO). The myocardial cell cultures from the UT group showed complete loss of beating when the calcium (Ca++) antagonist, V, was added to the cultures for 1 h or more; the T group was able to show some beating at comparable concentrations and durations of exposure with V.

Role of calcium in isoproterenol cytotoxicity to cultured myocardial cells.

Primary cultures of rat myocardial cells were used to evaluate the cellular dynamics of calcium accumulation after exposure to isoproterenol (ISO). Non-toxic concentrations of ISO (2.4 X 10(-7) M) caused a gradual increase in myocyte calcium uptake.

Attenuation by antioxidants of Na+/K+ ATPase inhibition by toxic concentrations of isoproterenol in cultured rat myocardial cells.

We have reported previously that toxic concentrations of isoproterenol caused severe alterations in the structural integrity of the sarcolemma and mitochondria found in primary cultures of rat myocardial cells [8, 9]. Mitochondrial injury was observed 1.5 h after exposure to isoproterenol, whereas leakage of intracellular ions and enzymes was observed only after prolonged exposures (greater than 4 h).

Cardiotoxicity of tricyclic antidepressants in primary cultures of rat myocardial cells.

Primary cultures of myocardial cells were used to evaluate the cardiotoxic potential of various tricyclic antidepressants (TCAs). Lactate dehydrogenase (LDH) leakage, cellular viability, and beating rates were measured to compare the cardiotoxicity of amitriptyline, desipramine, imipramine, and nortriptyline. Tricyclic antidepressants were added to the cultures to give final concentrations of 1 X 10(-5), 1 X 10(-4), and 1 X 10(-3) M.

Cytotoxicity of isoproterenol to cultured heart cells: effects of antioxidants on modifying membrane damage.

Primary cultures of rat myocytes were used to study the cardiac damage induced by toxic doses of L-isoproterenol (ISO). Cultures were exposed to varying concentrations of ISO (2.4 X 10(-5), 1 X 10(-4), and 5 X 10(-4) M) for 0.

Assessment of functional, morphological, and enzymatic tests for acute nephrotoxicity induced by mercuric chloride.

The relative merits of a comprehensive series of contemporary methods for detection of acute nephrotoxicity were evaluated. Male Sprague-Dawley rats were given 0, 0.25, 0.

Cellular injury of primary cultures of rat myocytes incubated in calcium-free medium followed by recovery in calcium.

Primary monolayer cultures of rat myocardial cells were used to study the cellular injury that occurs when calcium is reintroduced after a period of calcium depletion. Cultures were treated with a calcium-free balanced salt solution (BSS) for 2 h and were then incubated for different time periods in the presence of normocalcemic BSS (2.5 mM CaCl2).

Prevention by L(-) ascorbic acid of isoproterenol-induced cardiotoxicity in primary cultures of rat myocytes.

Primary cultures of rat myocytes were exposed to various doses of L-isoproterenol (ISO) for 4, 12 and 24 h. L-ascorbic acid (AA) was added to some cultures immediately after exposure to ISO to determine if antioxidants reduce the toxicity caused by ISO. Leakage of lactate dehydrogenase (LDH) and cell viability were used as indices of cell injury.