Guinea Pig Tissues Research Articles

MAG ‐ DPA curbs inflammatory biomarkers and pharmacological reactivity in cytokine‐triggered hyperresponsive airway models

Bronchial inflammation contributes to a sustained elevation of airway hyperresponsiveness (AHR) in asthma. Conversely, omega‐3 fatty acid derivatives have been shown to resolve inflammation in various tissues. Thus, the effects of docosapentaenoic acid monoacylglyceride (MAG‐DPA) were assessed on inflammatory markers and reactivity of human distal bronchi as well as in a cultured model of guinea pig tracheal rings. Human bronchi were dissected and cultured for 48 h with 10 ng/mL TNF‐α or IL‐13. Guinea pig tracheas were maintained in organ culture for 72 h which was previously shown to trigger spontaneous AHR. All tissues were treated with increasing concentrations of MAG‐DPA (0.1, 0.3, and 1 μmol/L). Pharmacomechanical reactivity, Ca2+ sensitivity, and western blot analysis for specific phosphoproteins and transcription factors were performed to assess the effects of both cytokines, alone or in combination with MAG‐DPA, on human and guinea pig airway preparations. Although 0.1 μmol/L MAG‐DPA did not significantly reduce inflammatory biomarkers, the higher concentrations of MAG‐DPA (0.3 and 1 μmol/L) blunted the activation of the TNF‐α/NF κB pathway and abolished COX‐2 expression in human and guinea pig tissues. Moreover, 0.3 and 1 μmol/L MAG‐DPA consistently decreased the Ca2+ sensitivity and pharmacological reactivity of cultured bronchial explants. Furthermore, in human bronchi, IL‐13‐stimulated phosphorylation of CPI‐17 was reversed by 1 μmol/L MAG‐DPA. This effect was further amplified in the presence of 100 μmol/L aspirin. MAG‐DPA mediates antiphlogistic effects by increasing the resolution of inflammation, while resetting Ca2+ sensitivity and contractile reactivity.

Compared with Powdered Lutein, a Lutein Nanoemulsion Increases Plasma and Liver Lutein, Protects against Hepatic Steatosis, and Affects Lipoprotein Metabolism in Guinea Pigs

Background: It is not clear how oil-in-water nanoemulsions of lutein may affect bioavailability and consequently alter lipoprotein metabolism, oxidative stress, and inflammation.Objective: The bioavailability as well as effects of a powdered lutein (PL) and an oil-in-water lutein nanoemulsion (NANO; particle size: 254.2 nm; polydispersity index: 0.29; and ζ-potential: −65 mV) on metabolic variables in liver, plasma, and adipose tissue in a guinea pig model of hepatic steatosis were evaluated.Methods: Twenty-four 2-mo-old male Hartley guinea pigs, weighing 200–300 g (n = 8/group), were fed diets containing 0.25 g cholesterol/100 g to induce liver injury for the duration of the study. They were allocated to control (0 mg lutein), PL (3.5 mg/d), or NANO (3.5 mg/d) groups. After 6 wk, plasma, liver, and adipose tissue were collected for determination of lutein, plasma lipids, tissue cholesterol, and inflammatory cytokines.Results: The NANO group had 2-fold higher concentrations of lutein in plasma (P < 0.001) and 1.6-fold higher concentrations in liver (P < 0.001) than did the PL group, indicating greater bioavailability of this carotenoid. The NANO group also had 24% lower hepatic steatosis scores (P < 0.05), 31% lower hepatic cholesterol accumulation (P < 0.05), and 64% lower plasma alanine aminotransferase (P < 0.05) than did the control group. Hepatic oxidized LDL was 55% lower in both the PL and NANO groups than in the control group (P < 0.05). In plasma, the NANO group had 2-fold higher concentrations of LDL and HDL cholesterol as well as a 2-fold higher number of VLDL, LDL, and HDL particles than did the other 2 groups as evaluated by nuclear magnetic resonance. Furthermore, the NANO group had 15% higher concentrations of free cholesterol in adipose tissue, resulting in higher concentrations of inflammatory markers, than did the other 2 groups.Conclusions: These results indicate that, although this lutein nanoemulsion exerted protective effects against hepatic steatosis, plasma lipoproteins and adipose tissue cholesterol were increased. These data suggest that the metabolic effects of this particular nanoemulsion might not be protective in all tissues in guinea pigs.

Simultaneous quantification of monoamine neurotransmitters and their biogenic metabolites intracellularly and extracellularly in primary neuronal cell cultures and in sub-regions of guinea pig brain.

In the present paper, we describe a validated chromatographic method for the simultaneous quantification of monoamine neurotransmitters and their biogenic metabolites intracellularly and extracellularly in primary neuronal cell culture and in sub-regions of the guinea pig brain. Electrochemical detection provided limits of quantifications (LOQs) between 3.6 and 12nM. Within the linear range, obtained recoveries were from 90.9±9.9 to 120±14% and intra-day and inter-day precisions found to be less than 5.5% and 12%, respectively. The analytical method was applicable for quantification of intracellular and extracellular amounts of monoamine neurotransmitters and their metabolites in guinea pig frontal cortex and hippocampal primary neuronal cell cultures. Noradrenaline, dopamine and serotonin were found to be in a range from 0.31 to 1.7pmol per 2 million cells intracellularly, but only the biogenic metabolites could be detected extracellularly. Distinct differences in monoamine concentrations were observed when comparing concentrations in guinea pig frontal cortex and cerebellum tissue with higher amounts of dopamine and its metabolites, 3,4-dihydroxyphenylacetic acid and homovanillic acid in frontal cortex, as compared to cerebellum. The chemical turnover in frontal cortex tissue of guinea pig was for serotonin successfully predicted from the turnover observed in the frontal cortex cell culture. In conclusion, the present analytical method shows high precision, accuracy and sensitivity and is broadly applicable to monoamine measurements in cell cultures as well as brain biopsies from animal models used in preclinical neurochemistry.

Contractile effects and receptor analysis of adenosine-receptors in human detrusor muscle from stable and neuropathic bladders.

To measure the relative transcription of adenosine receptor subtypes and the contractile effects of adenosine and selective receptor-subtype ligands on detrusor smooth muscle from patients with neuropathic overactive (NDO) and stable bladders and also from guinea-pigs. Contractile function was measured at 37°C in vitro from detrusor smooth muscle strips. Contractions were elicited by superfusate agonists or by electrical field stimulation. Adenosine-receptor (A1, A2A, A2B, A3) transcription was measured by RT-PCR. Adenosine attenuated nerve-mediated responses with equivalent efficacy in human and guinea-pig tissue (pIC50 3.65–3.86); the action was more effective at low (1–8 Hz) compared to high (20–40 Hz) stimulation frequencies in human NDO and guinea-pig tissue. With guinea-pig detrusor the action of adenosine was mirrored by the A1/A2-agonist N-ethylcarboxamidoadenosine (NECA), partly abolished in turn by the A2B-selectve antagonist alloxazine, as well as the A1-selective agonist N6- cyclopentyladenosine (CPA). With detrusor from stable human bladders the effects of NECA and CPA were much smaller than that of adenosine. Adenosine also attenuated carbachol contractures, but mirrored by NECA (in turn blocked by alloxazine) only in guinea-pig tissue. Adenosine receptor subtype transcription was measured in human detrusor and was similar in both groups, except reduced A2A levels in overactive bladder. Suppression of the carbachol contracture in human detrusor is independent of A-receptor activation, in contrast to an A2B-dependent action with guinea-pig tissue. Adenosine also reduced nerve-mediated contractions, by an A1- dependent action suppressing ATP neurotransmitter action.Electronic supplementary materialThe online version of this article (doi:10.1007/s00210-016-1255-1) contains supplementary material, which is available to authorized users.

Influence of fish oil on usage of [1-14С] palmitic acid in the synthesis of lipids in the tissues of guinea pigs under hypercholesterolemia in vitro

It’s studied in vitro the intensity of lipid synthesis of various classes (fatty acids, cholesterol, phospholipids and acylglycerols) in homogenates of liver, brain, small intestinal mucosa and adipose tissue after daily single injection of guinea pigs with cholesterol (300 mg/kg body weight) for 30 days. For this purpose, it’s determined the radioactivity of the lipid fractions of the referred above tissue homogenates of guinea pigs that was incubated with [1-14C] palmitic acid. It’s established the inhibitory effect of exogenous cholesterol, under increase its level in the diet of guinea pigs, on the diacylglycerol synthesis and on the free cholesterol in the small intestine mucosa and on the triacylglycerol synthesis in adipose tissue under usage as a precursor – [1-14C] palmitic acid. It’s determined a significant reduction in the intensity of total lipids and individual lipid classes by using as a precursor [1-14C] palmitic acid in in vitro conditions in the brain, liver, small intestinal mucosa and adipose tissue of guinea pigs with hypercholesterolemia when it’s given them fish oil as feed.

Application of a high-resolution benchtop quadrupole-Orbitrap mass spectrometry for the pharmacokinetics and tissue distribution of Danhong injection in guinea pig

Danhong injection (DHI) is a compound preparation of traditional Chinese medicine Salviae miltiorrhiza (a.k.a. Danshen) and Flos Carthami tinctorii. Phenolic acids, such as salvianic acid A sodium (SAS), protocatechualdehyde (PAL), salvianolic acid B (SAB) and flavonoids, such as rutin, are the main bioactive ingredients of DHI. This paper presents an application of ultra high-performance liquid chromatography and quadrupole-Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap HR MS) to quantify salvianic acid A sodium, protocatechualdehyde, salvianolic acid B, and rutin in guinea pig plasma and tissues for pharmacokinetic and tissue distribution studies. Biological samples were processed with methanol extraction, and calibration curves were determined with indometacin as internal standard (I.S.). The analytes were separated by a Hypersil GOLD aQ C18 column and detected using negative ion full MS/dd-MS2 (data-dependent MS2) mode. The full MS scan acquired data for identification and quantification, and dd-MS2 scan obtained product ion spectra for confirmation. The response showed good linear relationship over the concentration range between 10.22 and 5110ng/mL for salvianic acid A sodium, 10.06–5030ng/mL for salvianolic acid B, 11.12–5560ng/mL for protocatechualdehyde, and 10.58–5290ng/mL for rutin, all the coefficients of correlation (r2) >0.9990. The lower limit of quantification (LLOQ) was 10ng/mL for the analytes. Overall, the novel UHPLC-Q-Orbitrap has demonstrated great performance for rapidity, accuracy, high sensitivity, and high selectivity. It was successfully applied to the pharmacokinetic and tissue distribution studies of Danhong injection. These acquired data would provide helpful information for the clinical applications, mechanism studies, and technology promotion of DHI in the future.

Anti-Interleukin-1 Beta/Tumor Necrosis Factor-Alpha IgY Antibodies Reduce Pathological Allergic Responses in Guinea Pigs with Allergic Rhinitis.

This study aims to determine whether the combined blockade of IL-1β and TNF-α can alleviate the pathological allergic inflammatory reaction in the nasal mucosa and lung tissues in allergic rhinitis (AR) guinea pigs. Healthy guinea pigs treated with saline were used as the healthy controls. The AR guinea pigs were randomly divided into (1) the AR model group treated with intranasal saline; (2) the 0.1% nonspecific IgY treatment group; (3) the 0.1% anti-TNF-α IgY treatment group; (4) the 0.1% anti-IL-1β IgY treatment group; (5) the 0.1% combined anti-IL-1β and TNF-α IgY treatment group; and (6) the fluticasone propionate treatment group. The inflammatory cells were evaluated using Wright's staining. Histopathology was examined using hematoxylin-eosin staining. The results showed that the number of eosinophils was significantly decreased in the peripheral blood, nasal lavage fluid, and bronchoalveolar lavage fluid (P < 0.05), and eosinophil, neutrophil, and lymphocyte infiltration and edema were significantly reduced or absent in the nasal mucosa and lung tissues (P < 0.05) in the combined 0.1% anti-IL-1β- and TNF-α IgY-treated guinea pigs. The data suggest that topical blockade of IL-1β and TNF-α could reduce pathological allergic inflammation in the nasal mucosa and lung tissues in AR guinea pigs.

Molecular cloning, sequence identification and expression profile of domestic guinea pig (Cavia porcellus) UGT1A1 gene

ABSTRACTDomestic guinea pig is a model animal for human disease research. Uridine diphosphate glucuronosyltransferase 1 family, polypeptide A1 (UGT1A1) is an important human disease-related gene. In this study, the complete coding sequence of domestic guinea pig gene UGT1A1 was amplified by reverse transcription-polymerase chain reaction. The open reading frame of the domestic guinea pig UGT1A1 gene is 1602 bp in length and was found to encode a protein of 533 amino acids. Sequence analysis revealed that the UGT1A1 protein of domestic guinea pig shared high homology with the UGT1A1 proteins of degu (84%), damara mole-rat (84%), human (80%), northern white-cheeked gibbon (80%), Colobus angolensis palliatus (80%) and golden snub-nosed monkey (79%). This gene contains five exons and four introns, as revealed by the computer-assisted analysis. The results also showed that the domestic guinea pig UGT1A1 gene had a close genetic relationship with the UGT1A1 gene of degu. The prediction of transmembrane helices showed that domestic guinea pig UGT1A1 might be a transmembrane protein. Expression profile analysis indicated that the domestic guinea pig UGT1A1 gene was differentially expressed in detected domestic guinea pig tissues. Our experiment laid a primary foundation for using the domestic guinea pig as a model animal to study the UGT1A1-related human diseases.

A search for presynaptic inhibitory histamine receptors in guinea-pig tissues: Further H3 receptors but no evidence for H4 receptors

The histamine H4 receptor is coupled to Gi/o proteins and expressed on inflammatory cells and lymphoid tissues; it was suggested that this receptor also occurs in the brain or on peripheral neurones. Since many Gi/o protein-coupled receptors, including the H3 receptor, serve as presynaptic inhibitory receptors, we studied whether the sympathetic neurones supplying four peripheral tissues and the cholinergic neurones in the hippocampus from the guinea-pig are equipped with release-modulating H4 and H3 receptors. For this purpose, we preincubated tissue pieces from the aorta, atrium, renal cortex and vas deferens with 3H-noradrenaline and hippocampal slices with 3H-choline and determined the electrically evoked tritium overflow. The stimulation-evoked overflow in the five superfused tissues was inhibited by the muscarinic receptor agonist oxotremorine, which served as a positive control, but not affected by the H4 receptor agonist 4-methylhistamine. The H3 receptor agonist R-α-methylhistamine inhibited noradrenaline release in the peripheral tissues without affecting acetylcholine release in the hippocampal slices. Thioperamide shifted the concentration–response curve of histamine in the aorta and the renal cortex to the right, yielding apparent pA2 values of 8.0 and 8.1, respectively, which are close to its affinity at other H3 receptors but higher by one log unit than its pKi at the H4 receptor of the guinea-pig. In conclusion, histamine H4 receptors could not be identified in five experimental models of the guinea-pig that are suited for the detection of presynaptic inhibitory receptors whereas H3 receptors could be shown in the peripheral tissues but not in the hippocampus.This article is part of the Special Issue entitled ‘Histamine Receptors’.

Comparative Study of Protective Effects of Salbutamol and Beclomethasone against Insulin Induced Airway Hyper-reactivity on Isolated Tracheal Smooth Muscle of Guinea Pig.

Inhalational insulin was withdrawn from the market due to its potential to produce airway hyper-reactivity and bronchoconstriction. So the present study was designed to explore the acute effects of insulin on airway reactivity of guinea pigs and protective effects of salbutamol and beclomethasone against insulin induced airway hyper-responsiveness on isolated tracheal smooth muscle of guinea pig. Effects of varying concentrations of insulin (10(-7) to 10(-3) M), insulin pretreated with fixed concentration of salbutamol (10(-7) M) and beclomethasone (10(-6) M) were studied on isolated tracheal tissue of guinea pig by constructing cumulative concentration response curves. Changes in tracheal smooth muscle contractions were recorded on four channel oscillograph. The mean ± SEM of maximum amplitudes of contraction with increasing concentrations of insulin, insulin pretreated with fixed concentration of salbutamol and beclomethasone were 35 ± 1.13 mm, 14.55 ± 0.62 mm and 22 ± 1.154 mm respectively. Although salbutamol and beclomethasone both had a profound inhibitory effect on insulin induced airway hyper-reactivity, yet salbutamol is more efficacious than beclomethasone. So we suggest that pretreatment of inhaled insulin with salbutamol may be preferred over beclomethasone in amelioration of its potential respiratory adverse effects such as bronchoconstriction.

Molecular cloning and expression of the calmodulin gene from guinea pig hearts.

The aim of the present study was to isolate and characterize a complementary DNA (cDNA) clone encoding the calmodulin (CaM; GenBank accession no. FJ012165) gene from guinea pig hearts. The CaM gene was amplified from cDNA collected from guinea pig hearts and inserted into a pGEM®-T Easy vector. Subsequently, CaM nucleotide and protein sequence similarity analysis was conducted between guinea pigs and other species. In addition, reverse transcription-polymerase chain reaction (RT-PCR) was performed to investigate the CaM 3 expression patterns in different guinea pig tissues. Sequence analysis revealed that the CaM gene isolated from the guinea pig heart had ∼90% sequence identity with the CaM 3 genes in humans, mice and rats. Furthermore, the deduced peptide sequences of CaM 3 in the guinea pig showed 100% homology to the CaM proteins from other species. In addition, the RT-PCR results indicated that CaM 3 was widely and differentially expressed in guinea pigs. In conclusion, the current study provided valuable information with regard to the cloning and expression of CaM 3 in guinea pig hearts. These findings may be helpful for understanding the function of CaM3 and the possible role of CaM3 in cardiovascular diseases.

Compared to Regular Lutein, a Lutein Nano‐Emulsion Yields a More Atherogenic Lipoprotein Profile Associated with Higher Concentrations of Cholesterol in Adipose Tissue in Guinea Pigs

We challenged 24 guinea pigs (8/group) with a high cholesterol diet (0.25g/100g) alone (control group) or in combination with 3 mg/d of Regular lutein (R‐lutein) or 3 mg/d of lutein prepared in nano‐emulsion (NANO) (average particle diameter = 250 nm). After 6 weeks, guinea pigs were sacrificed and blood was collected to measure plasma lipids and lipoprotein size and number by Nuclear Magnetic Resonance and adipose was harvested to determine concentrations of both free and esterified cholesterol. Contrary to what we expected, guinea pigs from the NANO group had the greatest concentrations of plasma cholesterol (P&lt;0.001). In addition, the NANO group had higher concentrations of large VLDL and total LDL particles (p&lt;0.0001). Moreover, cholesterol concentration in the adipose tissue was highest in the NANO group (11.5 ± 2.5 mg/g), intermediate in the control group (10.2 ± 1.5 mg/g) and lowest in the R‐lutein group (9.2 ± 0.8 mg/g) (p&lt; 0.01). In contrast hepatic cholesterol concentrations were highest in the NANO compared to the R‐lutein and control groups (P &lt; 0.01). Further, we found a positive correlation between plasma cholesterol and free cholesterol in the adipose (r = 0.493, p = 0.014) and with large VLDL (r = 0.700, P &lt; 0.001). These data suggest that guinea pigs fed the NANO emulsion have lower concentrations of cholesterol in the liver because they are secreting cholesterol in the large VLDL particles and possibly both lipoproteins VLDL and LDL are depositing the excess cholesterol in extra‐hepatic tissues (adipose), possibly via scavenger receptors

Vascular Reactivity of Rat, Guinea‐pig, Rabbit and Human Vessels to Bufadienolides and Cardenolides

Cardenolides and bufodienolides are Na+-K+-ATPase (NKA) inhibitors. The aim of the present study was to evaluate the response to such compounds of vessels from different species in order to compare potency and efficacy. The experimental protocols were approved by the Animal Care and Ethics Committee of the Ceara State University. The aortic rings and mesenteric artery for isometric recordings of contractions in response to cumulative addition of OUA, BUF, DIG (0.1-100 µM). The contractions were expressed as percentage of the maximal contraction elicited by phenylephrine. Ouabain, up to 100 µM, promoted no contraction in rat aorta but promoted a slow onset contraction that attained a maximum of 71.5±14.8% and 101.2±8.5% in guinea-pig and rabbit tissue, respectively. Bufalin promoted slow onset contractions after 30 and 100 µM that reached a maximum of 20.6 ± 5.2%,55.0±10.5% and 94±19.8% in tissues gathered from rats, guinea-pigs and rabbits, respectively. On the other hand, digoxin did not elicit contraction in rabbit or rat aortic rings but elicited a similar slow onset that attained its maximum after more than 50 minutes and reached 79.7±15.6% in guinea-pig tissues. In human aortic rings in response to 100 µM bufalin or ouabain reached a maximum of 96.7±24.4% or 140±26.7%, respectively. In the 2nd branch of the mesenteric artery, BUF promoted a slow contractile response (46 % ± 9.6 %) only at a dose of 100 µM.Pretreatment with guanethidine (GUA + BUF) significantly attenuated BUF vasoconstriction in aortic rings (39.7% ± 8.4) and prazosin (1µM) completely blocked the contraction, suggesting and indirect noradrenergic activation.

The Effects of Hypogonadism and Conjugated Linoleic Acid on Regional Adipose Tissue and Fatty Acid Composition in Male Guinea Pigs

BackgroundAging in men is associated with gains in body fat, which are due in part to the age‐related decline in testosterone. Conjugated linoleic acid (CLA) has been consistently shown to reduce body fat or fat gain in animal models through a similarly suggested mechanism as testosterone. Therefore, CLA may counteract the progressive body fat gain that occurs with testosterone decline.Objectives.To determine whether CLA modulates changes in body fat, regional fat distribution and adipose tissue fatty acid composition in hypogonadal male guinea pigs.Methods.Male, retired breeder guinea pigs (n=40, 70‐72 wk) were block randomized by weight into 4 groups: 1) SHAM/ CTRL, 2) SHAM/ CLA diet (1%), 3) Orchidectomy (ORX)/ CTRL diet, 4) ORX/ CLA diet. Dual‐energy x‐ray absorptiometry scans were performed at baseline and 16 wk to analyze body composition. Visceral and subcutaneous adipose fatty acids were extracted and methylated for gas chromatography (GC) analysis to determine fatty acid composition.Results.In ORXCTRL guinea pigs, percent body fat increased by 6.1% and percent lean mass decreased by 6.7 % over the 16 wks while no significant changes in percent body composition were observed in ORXCLA guinea pigs. Guinea pigs fed CLA diet gained less % total body fat and % upper and lower body fat than those fed CTRL regardless of surgical treatment. Regional adipose tissue of fatty acid composition showed that it was reflective of dietary fatty acids.ConclusionHypogonadism in male guinea pigs results in increased fat mass and decreased lean mass. CLA is effective in reducing fat gain and maintaining lean mass in both hypogonadal and intact guinea pigs.

Proposal for standard methods and procedure for guinea pig carcass evaluation, jointing and tissue separation

The South American guinea pig rodent has become a livestock animal acceptable for human consumption in different parts of the world. Its white meat has a great potential as a new protein source, and its social and economic importance for different human populations is considered key for development. Scarce data are found in the literature when the statistical livestock information is checked, and few researches have been done about morphological characteristics of guinea pigs carcasses. These works do not follow the same procedures, using different criteria, overall the jointing, making it difficult to compare different studies. The aim of the present study is to suggest a practical and normalized method to analyse the guinea pig carcass characteristics allowing their evaluation. It describes the main traits to be considered from the birth of the animal to the carcass analysis. This work concerns: (1) growth, feeding, pre-slaughter and slaughter processing, (2) method for the definition, hanging and presentation of the carcass, (3) carcass morphological characteristics, (4) jointing procedure based on four anatomically defined regions, (5) methods for evaluating meat pH and colour and (6) method for tissue separation. This proposal could be useful to compare data of these animals under different conditions.

The guinea-pig expresses functional CYP2C and P-glycoprotein: further validation of its usefulness in drug biotransformation/transport studies.

The guinea-pig is an excellent animal model for studying cardiopulmonary physiology/pharmacology. Interestingly, it also possesses a number of drug-metabolizing enzymes found in humans, such as CYP1A, CYP2D and CYP3A. To evaluate the hypothesis that the guinea-pig also expresses a functional CYP2C drug-metabolizing enzyme and the P-glycoprotein (P-gp) drug transporter in various tissues. cDNAs encoding CYP2C and P-gp were obtained from guinea-pig liver or small intestine and sequenced. Western blotting was performed to confirm the expression of CYP2C and P-gp. The functional enzymatic activity of guinea-pig CYP2C was evaluated with microsomal preparations using diclofenac and tolbutamide as specific drug substrates in HPLC analyses. To further study both P-gp and CYP2C functional activities, the guinea-pig ABCB1/MDR1 and CYP2C genes were cloned. The recombinant plasmids were then transfected in HEK293 (human embryonic kidney) cells and either calcein-acetoxymethyl ester (AM) accumulation assays or 14,15-EET/DHET formation experiments were performed to evaluate either P-gp transport activity or CYP2C epoxygenase activity, respectively. The guinea-pig tissue distribution of P-gp was studied by Western blotting. Functional expression of CYP2C was demonstrated in guinea-pig liver microsomal preparations. CYP2C-mediated biotransformation of diclofenac and tolbutamide were shown. Expression of P-gp protein was detected in guinea-pig liver and small intestine. Functional activity of guinea-pig P-gp was demonstrated in ABCB1/MDR1-transfected cells. GP-CYP2C-transfected cells also showed functional epoxygenase activity. The guinea-pig expresses functional CYP2C and P-gp, thus suggesting its usefulness for further validating data obtained with other animal models in drug biotransformation/transport studies.

Alcohol Disrupts Levels and Function of the Cystic Fibrosis Transmembrane Conductance Regulator to Promote Development of Pancreatitis

Excessive consumption of ethanol is one of the most common causes of acute and chronic pancreatitis. Alterations to the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) also cause pancreatitis. However, little is known about the role of CFTR in the pathogenesis of alcohol-induced pancreatitis. We measured CFTR activity based on chloride concentrations in sweat from patients with cystic fibrosis, patients admitted to the emergency department because of excessive alcohol consumption, and healthy volunteers. We measured CFTR levels and localization in pancreatic tissues and in patients with acute or chronic pancreatitis induced by alcohol. We studied the effects of ethanol, fatty acids, and fatty acid ethyl esters on secretion of pancreatic fluid and HCO3(-), levels and function of CFTR, and exchange of Cl(-) for HCO3(-) in pancreatic cell lines as well as in tissues from guinea pigs and CFTR knockout mice after administration of alcohol. Chloride concentrations increased in sweat samples from patients who acutely abused alcohol but not in samples from healthy volunteers, indicating that alcohol affects CFTR function. Pancreatic tissues from patients with acute or chronic pancreatitis had lower levels of CFTR than tissues from healthy volunteers. Alcohol and fatty acids inhibited secretion of fluid and HCO3(-), as well as CFTR activity, in pancreatic ductal epithelial cells. These effects were mediated by sustained increases in concentrations of intracellular calcium and adenosine 3',5'-cyclic monophosphate, depletion of adenosine triphosphate, and depolarization of mitochondrial membranes. In pancreatic cell lines and pancreatic tissues of mice and guinea pigs, administration of ethanol reduced expression of CFTR messenger RNA, reduced the stability of CFTR at the cell surface, and disrupted folding of CFTR at the endoplasmic reticulum. CFTR knockout mice given ethanol or fatty acids developed more severe pancreatitis than mice not given ethanol or fatty acids. Based on studies of human, mouse, and guinea pig pancreata, alcohol disrupts expression and localization of the CFTR. This appears to contribute to development of pancreatitis. Strategies to increase CFTR levels or function might be used to treat alcohol-associated pancreatitis.

Distribution of Tocopherols and Tocotrienols in Guinea Pig Tissues Following Parenteral Lipid Emulsion Infusion.

Tocopherols and tocotrienols possess vitamin E activity and function as the major lipid-soluble antioxidants in the human body. Commercial lipid emulsions are composed of different oils and supply different amounts of vitamin E. The objective of this study was to measure all 8 vitamin E homologs within 4 different commercial lipid emulsions and evaluate their distribution in guinea pig tissues. The distribution of vitamin E homologs within plasma and guinea pig tissues was determined using a high-performance liquid chromatography (HPLC) system. Lipid hydroperoxides in lipid emulsions were determined using a commercial kit (Cayman Chemical Company, Ann Arbor, MI), and malondialdehyde tissue levels were determined using an HPLC system. The lipid emulsions contained variable amounts of tocopherols, which were significantly different between emulsions. Tocotrienols were present at very low concentrations (≤0.3%). We found no correlation between the amount of vitamin E present in the lipid emulsions and lipid peroxidation. Hydroperoxides were the lowest with an olive oil-based emulsion and highest with a fish oil emulsion. The predominant vitamin E homolog in guinea pig tissues was α-tocopherol. No tissues had detectable levels of tocotrienols. Vitamin E levels (primarily α-tocopherol and γ-tocopherol) were highly variable among organ tissues. Plasma levels were a poor reflection of most tissue levels. Vitamin E levels within different lipid emulsions and plasma/tissues are highly variable, and no one tissue or plasma sample serves as a good proxy for levels in other tissues. All study emulsions were well tolerated and did not significantly increase systemic lipid peroxidation.

Prevention of Oxidative Damage of Liver, Kidney and Serum Proteins with Apoptosis of above Tissues in Guinea Pigs Fed on Carbonated Soft Drink by Vitamin C

Prevention of Oxidative Damage of Liver, Kidney and Serum Proteins with Apoptosis of above Tissues in Guinea Pigs Fed on Carbonated Soft Drink by Vitamin C

Pathogenesis of a genotype C strain of bovine parainfluenza virus type 3 infection in albino guinea pigs

Bovine parainfluenza virus type 3 (BPIV3) is one of the most important of the known viral respiratory tract agents of both young and adult cattle and widespread among cattle around the world. Up to present, three genotypes A, B and C of BPIV3 have been described on the basis of genetic and phylogenetic analysis and only limited studies on the pathogenesis of the genotype A of BPIV3 infection in calves and laboratory animals have been performed. The report about experimental infections of the genotypes B and C of BPIV3 in laboratory animals and calves was scant. Therefore, an experimental infection of guinea pigs with the Chinese BPIV3 strain SD0835 of the genotype C was performed. Sixteen guinea pigs were intranasally inoculated with the suspension of SD0835, while eight control guinea pigs were also intranasally inoculated with the same volume of supernatant from uninfected MDBK cells. The virus-inoculated guinea pigs displayed a few observable clinical signs that were related to the respiratory tract disease and two of the sixteen experimentally infected guinea pigs died at 2 and 3 days post inoculation (PI), respectively, and apparent gross pneumonic lesions were observed at necropsy. The gross pneumonic lesions in guinea pigs inoculated with SD0835 consisted of dark red, slightly depressed, irregular areas of consolidation in the lung lobes from the second to 9th day of infection at necropsy, and almost complete consolidation and atelectasis of the lung lobes were seen at 7 days PI. Histopathological changes including alveoli septa thickening and focal cellulose pneumonia were also observed in the lungs of guinea pigs experimentally infected with SD0835. Viral replication was detectable by virus isolation and titration, real-time RT-PCR and immunohistochemistry (IHC) staining in the respiratory tissues of guinea pigs as early as 24h after intranasal inoculation with SD0835. The results of virus isolation and titration showed that guinea pigs were permissive for SD0835 replication and exhibited a higher virus replication level in both lungs and tracheas. As well, the results of IHC staining implicated that the lungs and tracheas were the major tissues in which SD0835 replicated. Virus-specific serum neutralizing antibodies against BPIV3 were detected in virus-inoculated guinea pigs. The aforementioned results indicated that BPIV3 strain SD0835 of the genotype C was pathogenic to guinea pigs and could cause a few observable clinical signs, and gross and histologic lesions in virus-inoculated guinea pigs. Thus guinea pig is an ideal laboratory animal infection model for BPIV3 and would cast more light on the genotype C of BPIV3 infection process, in vivo tropism and pathogenesis or serve as a useful system for monitoring the pathogenesis of SD0835 and other BPIV3 isolates.