Guinea Pig Liver Research Articles

Effect of reserpine on the histaminolytic activity of guinea-pig liver.

Journal Article Effect of reserpine on the histaminolytic activity of guinea-pig liver Get access B P Udwadia, B P Udwadia Department of Pharmacology, M.P. Shah Medical College, Jamnagar, India Search for other works by this author on: Oxford Academic Google Scholar K S Sachdev, K S Sachdev Department of Pharmacology, M.P. Shah Medical College, Jamnagar, India Search for other works by this author on: Oxford Academic Google Scholar D J Joshi D J Joshi Department of Pharmacology, M.P. Shah Medical College, Jamnagar, India Search for other works by this author on: Oxford Academic Google Scholar Journal of Pharmacy and Pharmacology, Volume 18, Issue 5, May 1966, Pages 321–322, https://doi.org/10.1111/j.2042-7158.1966.tb07880.x Published: 12 April 2011 Article history Received: 15 February 1966 Published: 12 April 2011

N-methylation of nicotine enantiomers by human liver cytosol.

Incubation of human liver cytosol with either R-(+)-[3H-N'CH3]nicotine or S-(-)-[3H-N'CH3]nicotine results in the formation of the corresponding N-methyl quaternary ammonium metabolite. A substrate stereoselectivity was observed in that the turnover number for the methylation of the S-(-)-isomer was 0.25 pmol mg-1 protein h-1, whereas that for the R-(+)-isomer was 2.11. The latter substrate exhibited an apparent Km value of 20.1 microM. Nicotine N-methylation appears to be species-dependent, since rat liver homogenates contained no 'nicotine N-methyltransferase' activity, whereas with guinea-pig liver homogenates, a substrate specificity for only R-(+)-nicotine was observed.

The in vivo metabolism of isomeric methoxyoxindoles

Abstract Isomeric methoxyoxindoles are metabolised by rats, guinea-pigs and rabbits to phenolic metabolites by O-demethylation and hydroxylation. This has been shown by comparison of the physical characteristics of the metabolites with those of standard synthetic hydroxyoxindoles. Negligible O-demethylation of methoxyoxindoles occurs with rat or guinea-pig liver microsome preparations, when compared with those of rabbit, but significant O-demethylation occurs with rat liver slices.

Antioxidant and anti‐inflammatory effects of lutein in aorta and liver of guinea pigs fed with a hypercholesterolemic diet.

The effects of the carotenoid, lutein on atherosclerosis and liver oxidation were tested in guinea pigs fed a hypercholesterolemic diet (0.25 g/100 g dietary cholesterol). Guinea pigs were divided into two groups, control group (n = 9) or Lutein group (n = 10) (0.1 g/100 g lutein) and fed the experimental diets for 12 wk. Hematoxylin and eosin (H&E) stained aorta was examined and aortic and liver malondialdehyde (MDA) concentrations were analyzed by TBARS assay. Plasma and aortic cytokine concentrations were measured by Immunoassay and liver enzymes, alkaline phosphatase (ALP) and alanine transaminase (ALT) were measured. Aortic MDA concentrations were lower in the Lutein (1.7 ± 1.3 nmol/mg protein) compared to the control group (3.0 ± 1.4 nmol/mg protein) (P < 0.05) and H&E staining indicated separation and disrupted morphology of aortas in control guinea pigs while these features were not shown in the Lutein group. Aortic MDA positively correlated with aortic cytokines. Plasma concentration of ALP and ALT were not different between groups, however, liver MDA concentrations were lower in the Lutein group (6.0 ± 1.0 nmol/mg protein) compared to the control group (7.0 ± 1.0 nmol/mg protein) (P < 0.05). Liver MDA concentrations were negatively correlated with liver lutein concentrations (r=−0.469, p<0.05). These results suggest protective antioxidant and anti‐inflammatory effects of lutein in both liver and aorta.

Synthesis, metabolic stability and antiviral evaluation of various alkoxyalkyl esters of cidofovir and 9-( S)-[3-hydroxy-2-(phosphonomethoxy)propyl]adenine

Alkoxyalkyl esters of cidofovir (CDV) are orally active agents which inhibit the replication of a variety of double stranded DNA (dsDNA) viruses including variola, vaccinia, ectromelia, herpes simplex virus, cytomegalovirus, adenovirus and others. One of these compounds, hexadecyloxypropyl-CDV (HDP-CDV, CMX001) is in clinical development for prevention and treatment of poxvirus infection, vaccination complications, and for infections caused by cytomegalovirus, adenovirus, herpesviruses and other dsDNA viruses. This class of lipid analogs is potentially prone to undergo omega oxidation of the alkyl moiety which can lead to a short chain carboxylic acid lacking antiviral activity. To address this issue, we synthesized a series of alkoxyalkyl or alkyl glycerol esters of CDV and ( S)-HPMPA having modifications in the structure of the alkyl residue. Antiviral activity was assessed in cells infected with vaccinia, cowpox or ectromelia viruses. Metabolic stability was determined in S9 membrane fractions from rat, guinea pig, monkey and human liver. All compounds had substantial antiviral activity in cells infected with vaccinia, cowpox or ectromelia. Metabolic stability was lowest in monkey liver S9 incubations where rapid disappearance of HDP-CDV and HDP-( S)-HPMPA was noted. Metabolic stability in monkey preparations increased substantially when a ω-1 methyl group (15-methyl-HDP-CDV) or a terminal cyclopropyl residue (14-cyclopropyl-tetradecyloxypropyl-CDV) was present in the alkyl chain. The most stable compound was 1- O-octadecyl-2- O-benzyl- sn-glycero-3-CDV (ODBG-CDV) which was not metabolized extensively by monkey liver S9. In rat, guinea pig or human liver S9 incubations, most of the modified antiviral compounds were considerably more stable.

Ethanol Predominantly Constricts Pre-sinusoids of Isolated Perfused Livers of Rat, Guinea pig and Mouse

Ethanol constricts hepatic vessels of isolated perfused livers of rats, but not dogs. However, it is not known whether ethanol constricts or dilates the hepatic vessels in other species such as guinea pigs and mice. In addition, the sites of hepatic venoconstriction induced by ethanol were not known in rat livers. We therefore studied the effects of ethanol on the segmental hepatic vascular resistance and liver weight of mice, rats and guinea pigs. The isolated livers were portally perfused with diluted blood at constant flow. The sinusoidal pressure was measured by the double occlusion method and was used to determine the pre- and post-sinusoidal resistance. The change of liver weight was also measured. Ethanol was administered cumulatively into the perfusate to gain clinically relevant concentrations of 1-300mM. Ethanol dose dependently caused predominant pre-sinusoidal constriction in livers of all three species. When compared with the livers of the guinea pigs and rats, the mouse livers were the weakest in response. Dose-dependent decreases in liver weight and bile flow accompanied predominant pre-sinusoidal constriction in guinea pigs and rats. Ethanol predominantly constricts pre-sinusoids in rat, guinea pig and mouse livers, although the mouse liver response was much weaker. Ethanol-induced pre-sinusoidal constriction is accompanied by reduction of liver blood volume in guinea pigs and rats.

Effect of Selenium-Containing Products on Antioxidant Enzyme Activity in the Kidneys, Liver, and Blood of Guinea Pigs

The antioxidant system of some tissues in guinea pigs with no selenium deficiency was studied after treatment with selenium-containing products. Activity of a selenium-containing enzyme glutathione peroxidase was significantly reduced in the kidneys and blood. The kidneys were characterized by low activity of glutathione reductase and high activity of SOD. These features illustrate the development of oxidative stress in the kidneys.

Development of hepatocyte-embedded hydrogel-filled macroporous scaffold cultures using transglutaminase

We aimed to develop cell-embedded gel-filled macroporous scaffold (CGS) culture technology as a fundamental technology for the construction of large-scale tissue-like structures, which will be indispensable for practical liver tissue engineering. Tissue transglutaminase (tTGase) from guinea pig liver showed no cytotoxicity toward primary hepatocytes, and hepatocyte-embedded gelatin gel cultures could be realized. The albumin production activities in tTGase-mediated hepatocyte-embedded gelatin gel cultures were similar to those in collagen gel cultures, representing an established hepatocyte culture method for the expression of liver-specific functions. Therefore, it was expected that a hepatocyte-embedded gelatin gel culture system enabling high liver-specific function expression could be created. The CGS culture system was created by incubating a suspension of hepatocytes and tTGase-containing gelatin-filled hydrophilic-treated scaffolds at 37 °C. The albumin production activities in CGS with poly( l-lactic acid) macroporous scaffold (porosity = 68.4%) were inferior to those in tTGase–gelatin gel cultures because of a diffusion problem. However, the activities were similar between CGS with macroporous polyurethane foam (porosity = 98.8%) and tTGase–gelatin gel cultures, even under stationary conditions. On the other hand, further functional improvements of hepatocytes were achieved in HGF- or HGF/heparin-containing gel cultures. Based on these results, tTGase-mediated CGS cultures are expected to become a fundamental technology for the creation of engineered liver tissues.

Effects of Vanadium Pentoxide on the Histological and Sperm Parameters of Male Guinea Pigs

The pharmacological effects of intraperitoneal administration of different doses of vanadium pentoxide (V2O5) on the histological and sperm parameters of male guinea pigs were investigated. Also investigatedwere the effects of oral pretreatment with different doses of vitamin E (a known protein kinase C inhibitor) on the V2O5 -induced responses of the testis and liver of male guinea pigs. In n = 5 experiments, vanadium pentoxide in the dose range of 4.5-12.5mg/kg caused destruction of the testicular and liver architecture. This was characterized by areduction in spermatogonia, destruction of seminiferous tubules, necrosis of the testicular tissues, necrosis of liver cells, fatty cells infiltration and vacoulation. Oral administration/ pretreatment with vitamin E in the dose range of 500-2000I.U caused a reversal of the vanadium pentoxide –induced histological damages of the testis and the liver cells. Furthermore, in n = 5 animals experiments, Vanadium pentoxide (4.5-12.5 mg/kg/) caused a statistically significant increase in the percentage basal cell death, from 5.0 to 75.0 ± 1.0%, reduction in sperm motility from 90.0 to 31.0 ± 3.9%, reduction in sperm count from 80.0 x106cells/ml to 25.0± 4.0 x 106cells/ml and alteration in the spermatic cell morphology ( i.e. causing a change in the cellular structure of sperm cells and an increase in abnormal cells count) of the male guinea pigs. These inhibitory effects were significant at P < 0.05 (ANOVA). These effects were all dose- and time-dependent and may have a role in oxidative pathology of vanadium pentoxide.

Distribution and possible origin of neuropeptide-containing nerve elements in the mammalian liver

The intrahepatic distribution of nerve fibres is highly species dependent, therefore we searched for a species where the innervation pattern is similar to that of the human liver. Livers of rats, cats, guinea pigs and humans were used. The different nerve elements were identified by ABC immunohistochemistry and analysed semiquantitatively. Large numbers of neuropeptide Y (NPY) and dopamine-beta-hydroxylase immunoreactive (IR) nerve fibres were observed in the human and guinea pig liver, and they were in close contact with portal triads, central veins and ran parallel with liver sinuses. A few substance P, somatostatin and vasoactive intestinal polypeptide IR nerve fibres were also detected intralobularly, while galanin nerve fibres were only observed around portal triads. In the rat liver only a few NPY-positive nerve fibres were found, exclusively in portal tracts. Some nerve cell bodies (IR for NPY and somatostatin) were also found in the liver of guinea pigs, young cats and humans, therefore some of the nerve terminals might originate from these intrinsic ganglia. It can be concluded that the innervation pattern of the guinea pig liver shows the highest similarity to that of the human liver.

Photo‐crosslinking Reveals Unique Features of the Sigma‐1 Receptor Ligand Binding Region(s)

We have recently found that endogenous sphingolipids including sphingosine and sphinganine interact with the sigma‐1 receptor. To study the interaction of these lipid molecules with the receptor, we used a series N‐alkylamines and their phenylpropyl‐ as well as nitrophenylpropyl‐ derivatives as surrogates for sphingosine. Surprisingly, N‐(3‐(4‐nitrophenyl)propyl)‐N‐alkylamines, revealed a unique property of the sigma‐1 receptor whereby upon UV irradiation of the receptor in the presence of excess compounds, two sigma‐1 receptor populations were generated. The first population migrated as a 26 kDa and the second as 23 kDa on an SDS polyacrylamide gel with a ratio of 1:1. Using anti‐sigma‐1 receptor antibody, we also detected this phenomenon in both guinea pig liver membranes and COS‐7 cells overexpressing the sigma‐1 receptor. Generation of these two sigma‐1 receptor populations was dependent on photolysis of N‐alkylamine derivatives of 12 carbons or longer and was protectable by haloperidol. The 23 kDa population was not formed as a result of photo‐chemical cleavage of the sigma‐1 receptor since both of the N‐ and C‐termini are presence as confirmed by N‐terminal sequencing and western analysis using an anti‐C‐term hexahistidine antibody. Sequence specific antibodies against amino acids 143 – 169 of the sigma‐1 receptor showed that in the 23 kDa, the N‐alkylamine photoprobe blocked the antibody epitope of this region. Additionallly, MALDI‐TOF results showed that there is a 318 Da shift of the peptide corresponding to amino acids 143 – 175, suggesting a covalent cross‐linking of photoprobe to the pure protein. Together, these data reveal unique features of the sigma‐1 receptor binding region(s).

In Vitro Interaction of 5-Hydroxytrptamine with Cytosolic Molybdenum Hydroxylases as a Potential Inhibitor for Initial Rates Activities

Problem statement: The role of 5-HT has been investigated in many behavioral activities. Thus, studies using raphe lesion showed that 5-HT is involved in sleep, general activity levels, habituation, aggression, pain sensitivity and morphine analgesia, avoidance behavior, self-stimulation and water consumption. Approach: The metabolic interaction between serotonin (5- hydroxytrptamine) and indole-3-aldehyde and xanthine via aldehyde oxidase (EC 1.2.3.1) and xanthine oxidase (EC 1.1.3.22), respectively, were studied in liver tissue homogenate of Dunkin-Hartley guinea pigs by following the decrease in substrate concentration using spectrophotometer. Homogenates of liver were incubated with indole-3-aldehyde in the presence and absence of serotonin or (chlorpromazine and allopurinol a potent and selective inhibitors for aldehyde oxidase and xanthine oxidase, respectively). Oxidation of indole-3-aldehyde to indole-3-acetic acid was reduced up to 63.2% in the presence of serotonin (100 µM), while oxidation of xanthine to uric acid was reduced up to 51.6% under the same conditions. Results: In comparison, incubation of the substrates with their specific inhibitors (100 µM of chlorpromazine and 100 µM allopurinol) give almost complete inhibition. These results demonstrate that in the guinea pig liver a metabolic interaction between serotonin and indole-3-aldehyde or xanthine via molybdenum hydroxylases system may take place in liver, which is the main tissue for xenobiotics detoxification. Conclusion: The overall conclusion from this research is that serotonin could be a protector for neurons and other tissue from the insult of oxidation of aldehydes and xanthines by molybdenum hydroxylases.

Non-steroidal anti-inflammatory drugs inhibit epinephrine- and cAMP-mediated lipolysis in isolated rat adipocytes.

Acute ethanol intoxication increased triacylglycerides (TAG) and thiobarbituric acid reactive substances (TBARS) in liver and promoted the liberation of epinephrine. Four non-steroidal anti-inflammatory drugs (NSAIDs)--aspirin, naproxen, nimesulide and piroxicam--prevented this increase in TAG and TBARS. Because fatty acids provided by adipose tissue contribute substantially to elevated hepatic TAG in ethanol-intoxicated rats, it was thought that the NSAIDs might reduce epinephrine-stimulated lipolysis in these rats. Isolated rat adipocytes were activated with epinephrine in the presence or absence of the NSAIDs. The NSAIDs inhibited epinephrine-stimulated lipolysis. These drugs did not modify the binding of dihydroalprenolol (beta-adrenergic agonist) to their receptors in isolated guinea-pig liver membranes. The NSAIDs, at concentrations 3,000-fold lower than that of cAMP, inhibited stimulated lipolysis by this messenger. In conclusion, aspirin, naproxen, nimesulide and piroxicam reduce the release of fatty acids from adipose tissue to the liver by inhibiting the epinephrine-stimulated lipolysis, and this, in part, explains the protective action of these NSAIDs against hepatic signs of acute ethanol intoxication.

Post-translational modification of glutamine and lysine residues of HIV-1 aspartyl protease by transglutaminase increases its catalytic activity

The human immunodeficiency virus type 1 aspartyl protease (HIV-1 PR) is a homodimeric aspartyl endopeptidase that is required for virus replication. HIV-1 PR was shown to act in vitro as acyl-donor and -acceptor for both guinea pig liver transglutaminase (TG, EC 2.3.2.13) and human Factor XIIIa. These preliminary evidences suggested that the HIV-1 PR contains at least three TG-reactive glutaminyl and one lysyl residues. We report here that the incubation of HIV-1 PR with TG increases its catalytic activity. This increase is dependent upon the time of incubation, the concentration of TG and the presence of Ca 2+. Identification of ε-(γ-glutamyl)lysine in the proteolytic digest of the TG-modified HIV-1 PR suggested intramolecular covalent cross-linking of this protease which may promote a non-covalent dimerization and subsequent activation of this enzyme via a conformational change. This hypothesis is supported by the observation that the TG-catalyzed activation of HIV-1 PR was completely abolished by spermidine (SPD) which acts as a competitive inhibitor of ε-(γ-glutamyl)lysine formation. Indeed, in the presence of 1 mM SPD the formation of the isopeptide was decreased of about 80%. The main products of the TG-catalyzed modification of HIV-1 PR in the presence of SPD were N 1- mono(γ-glutamyl)SPD and N 8- mono(γ-glutamyl)SPD. Negligible amount of N 1,N 8- bis(γ-glutamyl)SPD were found. The significance of these results is discussed with respect to the activation of the protease by post-translational modification and design of potential inhibitors.

Study on skin sensitization as well as liver and kidney impairment in guinea pigs treated with trichloroethylene

To study skin sensitization as well as liver and kidney impairment in guinea pigs treated with trichloroethylene (TCE). Guinea pig maximization test (GPMT) was applied in this study, guinea pigs were divided into 3 groups, namely negative control, positive control and TCE treatment. Animals of 3 groups were administrated with olive oil, 2, 4-dinitrochlorobenzene (DNCB), and TCE, respectively, by intradermal injection. The animal skin was observed and blood was collected after various treatment, the liver function tests were conducted, including detection of activities of ALT, AST, LDH and levels of creatinine, uric acid, and urea with automatic biochemical analyzer. Obvious skin impairment was observed in the groups of positive control and TCE treatment, the skin impairment included erythema and edema, the sensitization rate was 100% in positive control and 83.3% in TCE treatment group. Additionally, the activities of ALT, AST and LDH increased significantly in the groups of positive control and TCE treatment when compared with the negative control. Trichloroethylene is one of the strong hypersensitizing substances, it could induce skin allergic reaction and liver impairment in guinea pigs.

Study on the Pathogenesis of Foreign Body Granulomatous Inflammation in the Livers of Sprague-Dawley Rats

Focal granulomatous inflammation developed in the livers of five 10-week-old male Sprague-Dawley rats. The characteristic features of this lesion were the presence of foreign body multinucleated giant cells engulfing calcium deposits and site-specific development in a fissure formed in a sub-lobation in the left lobe or interlobar fissure of the medial lobe of the liver. To clarify the pathogenesis of this lesion, rat livers showing abnormal sub-lobation or lobar atrophy, rat livers in an acute dermal toxicity study and guinea pig livers in a skin sensitization test were also examined histologically. Consequently, the present lesion was considered to be a reactive change against calcium that was dystrophically deposited in the area of hepatocellular necrosis due to delayed circulatory disturbance caused by external pressure or extension force. Granulomatous lesions like in the present cases should be differentiated from those caused by evident exogenous pathogens such as chemicals or microorganisms.

Qualitative and quantitative analysis of retinol, retinyl esters, tocopherols and selected carotenoids out of various internal organs form different species by HPLC.

We report the validation of a reversed-phase gradient HPLC method allowing simultaneous quantification of retinol, retinyl esters, tocopherols and selected carotenoids in lung, liver and plasma of mouse, rat and guinea pig (gp) using a diode array detector. A significant species difference was observed regarding the distribution of retinol and retinyl esters. The levels of total retinol in lung, liver and plasma were in the following order: mouse >> rat > gp; rat >mouse > gp; and gp >> rat > mouse, respectively. Furthermore, comparison studies revealed similarities between the vitamin A profiles of human and gp lung samples.

DEVELOPMENT OF A SENSITIVE SPECTROFLUOROMETRIC-MULTIVARIATE CALIBRATION METHOD FOR ENZYME KINETIC OF ALDEHYDE OXIDASE

Attempts to obtain experimental values for the kinetic parameters of phenanthridine oxidation by guinea pig or rabbit liver aldehyde oxidase using common spectrophotometric methods have not been successful due to a lower limit of detection. In the present study, a new spectrofluorimetric assay in combination with a multivariate calibration method for enzymatic kinetic study of aldehyde oxidase activity, using phenanthridine as the substrate, has been developed and validated. Phenanthridine and phenanthridinone binary mixtures were prepared in a dynamic linear range of 0.025-1 µM and the emission flourimetric spectra of the solutions recorded at the excitation and emission wavelengths of 236 and 320-450 nm, respectively. The optimized calibration model of partial least squares (PLS) method was applied for the simultaneous determination of the concentration of each chemical in the prediction set. The limits of detection for phenanthridine and phenanthridinone were found to be 2.13 ± 0.33 and 3.41 ± 0.34 nM (mean ± SD, n = 5), respectively. This method was then used for kinetic study of phenanthridine oxidation using guinea pig and rat hepatic aldehyde oxidase. The results were compared with those obtained from a univariate spectroscopic method. Using this new spectrofluorimetric-multivariate calibration method, the K m value for the oxidation of phenanthridine with guinea pig and rat liver aldehyde oxidase were obtained as 0.83 ± 0.08 and 2.20 ± 0.40, µM (mean ± SD, n = 3), respectively.

Polymeric Osteopontin Employs Integrin α9β1 as a Receptor and Attracts Neutrophils by Presenting a de Novo Binding Site

Osteopontin (OPN) is a cytokine and ligand for multiple members of the integrin family. OPN undergoes the in vivo polymerization catalyzed by cross-linking enzyme transglutaminase 2, which consequently increases the bioactivity through enhanced interaction with integrins. The integrin alpha9beta1, highly expressed on neutrophils, binds to the sequence SVVYGLR only after intact OPN is cleaved by thrombin. The SVVYGLR sequence appears to be cryptic in intact OPN because alpha9beta1 does not recognize intact OPN. Because transglutaminase 2-catalyzed polymers change their physical and chemical properties, we hypothesized that the SVVYGLR site might also be exposed on polymeric OPN. As expected, alpha9beta1 turned into a receptor for polymeric OPN, a result obtained by cell adhesion and migration assays with alpha9-transfected cells and by detection of direct binding of recombinant soluble alpha9beta1 with colorimetry and surface plasmon resonance analysis. Because the N-terminal fragment of thrombin-cleaved OPN, a ligand for alpha9beta1, has been reported to attract neutrophils, we next examined migration of neutrophils to polymeric OPN using time-lapse microscopy. Polymeric OPN showed potent neutrophil chemotactic activity, which was clearly inhibited by anti-alpha9beta1 antibody. Unexpectedly, mutagenesis studies showed that alpha9beta1 bound to polymeric OPN independently of the SVVYGLR sequence, and further, SVVYGLR sequence of polymeric OPN was cryptic because SVVYGLR-specific antibody did not recognize polymeric OPN. These results demonstrate that polymerization of OPN generates a novel alpha9beta1-binding site and that the interaction of this site with the alpha9beta1 integrin is critical to the neutrophil chemotaxis induced by polymeric OPN.

The Journal of Biological Chemistry, Volume 203, 1953: Enzyme secretion and the incorporation of P32 into phospholipides of pancreas slices.

1. When enzyme secretion was stimulated by carbamylcholine or acetylcholine (with eserine) in slices of pigeon pancreas, the incorporation of P32 into the phospholipide fraction of the stimulated slices was, after 2 hours, 4.8 to 8.7 (average, 7.0) times greater than the incorporation of P32 into the phospholipides of control slices. Neither respiration nor the incorporation of P32 into acid-soluble phosphate esters was increased. 2. Pilocarpine, which on a weight for weight basis was much less effective than carbamylcholine or acetylcholine in stimulating enzyme secretion in pancreas slices, was also much less effective in stimulating the uptake of P32 into phospholipides. 3. The stimulatory effects of carbamylcholine on both enzyme secretion and the incorporation of P32 into phospholipides were abolished by atropine. 4. The specific activity of the phospholipides from slices incubated anaerobically was less than 5 per cent of that observed aerobically. Anaerobically, carbamylcholine did not stimulate the incorporation of P32 into phospholipides to any significant extent. The specific activity of the acid-soluble phosphate esters after anaerobic incubation was 34 per cent of that found aerobically. 5. Cholinergic drugs had little or no effect on the incorporation of P32 into the phospholipides of the following tissue slices: pigeon and guinea pig liver, guinea pig heart ventricle, pigeon gizzard (smooth muscle), and guinea pig kidney cortex. A relatively slight stimulation of P32 uptake into phospholipides was observed in slices of pigeon brain (65 per cent) and guinea pig brain cortex (40 per cent). 6. Stimulation of amylase synthesis in slices of pigeon pancreas by the addition of a mixture of amino acids had no effect on the incorporation of P32 into phospholipides.