Dissolution of gallstones in hamsters by 3-hydroxy-3-methylglutaric acid

Summary Addition of 0.05–0.20% of 3-hydroxy-3-methylglutaric acid to a lithogenic hamster diet resulted in a marked reduction in the incidence of gallstones in hamsters.Supported, in part, by grants HL-03299, AG-00076 and T32 CA-09171 and a Research Career Award, HL-0734 from the National Institutes of Health.     

Forskolin supresses seizures induced by pentylenetrazol in mice

Summary Forskolin, an adenylate cyclase activator when injected s.c. (1 mg/kg) in mice, caused an elevation of cAMP in the forebrain and cerebellum of up to 170% and 130%, respectively. The treatment was found to prevent seizures induced by pentylenetetrazol. This suppression had subsided 30 min after the injection, when cAMP level was again normal in the cerebellum but still elevated in the forebrain.     

Forskolin suppresses seizures induced by pentylenetetrazol in mice

Forskolin, an adenylate cyclase activator when injected s.c. (1 mg/kg) in mice, caused an elevation of cAMP in the forebrain and cerebellum of up to 170% and 130%, respectively. The treatment was found to prevent seizures induced by pentylenetetrazol. This suppression had subsided 30 min after the injection, when cAMP level was again normal in the cerebellum but still elevated in the forebrain.     

Immune-mediated glomerulonephritis induced by mercuric chloride in mice

Summary The BALB/c mouse developed mesangial deposits of immune constituents and light microscopical changes characteristic of immune complex glomerulonephritis after 8 weeks' treatment with mercuric chloride given by s.c. injection. There were no signs of linear of granular immune deposits along the glomerular capillary basement membrane after 2 or 8 weeks. The antigen could not be identified. No antibodies to nuclear or renal structures were found. Using a histochemical method (silver amplification) mercury was detected by light and electron microscopy in tubular and glomerular structures. Mercury was present in secondary lysosomes of the mesangial cells after eight weeks of mercury poisoning.We are deeply indebted to Dr. Gorm Danscher, Institute of Anatomy, B., University of Aarhus, Denmark, for valuable discussions and technical advice. This work was supported by the Swedish Medical Research Council, project no 6536.     

Modification by levo-propranolol of tremors induced by harmine in mice

Summary It has been recently reported that the levo isomer of propranolol possesses anti-serotonin properties in animals. Since harmine-induced behavioural changes in mice are reported to be mediated through central serotonergic receptors, an attempt was made to test whether 1-propranolol would also modify harmine-induced responses by virtue of its antiserotonergic or anti-adrenergic property. The results indicated that 1- and dl-propranolol inhibited central serotonin receptor mediated responses to harmine in mice, a finding that is analogous to other recent observations.     

Modification by levo-propranolol of tremors induced by harmine in mice

It has been recently reported that the levo isomer of propranolol possesses anti-serotonin properties in animals. Since harmine-induced behavioural changes in mice are reported to be mediated through central serotonergic receptors, an attempt was made to test whether 1-propranolol would also modify harmine-induced responses by virtue of its anti-serotonergic or anti-adrenergic property. The results indicated that l- and dl-propranolol inhibited central serotonin receptor mediated responses to harmine in mice, a finding that is analogous to other recent observations.     

Formation of 2-hydroxy-6-oxo-2,trans-4,trans-heptadienoic acid from 3-methylcatechol by aPseudomonas

Riassunto Ps. desmolyticum ossida la 3-metilpirocatechina ad acido 2-ossi-6-oxo-2,trans-4,trans-eptadienoico. Vengono descritte le proprietà chimicofisiche che hanno condotto all'identificazione di questo intermedio metabolico.

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This work was supported by C.N.R. (Consiglio nazionale delle Ricerche).     

Hypothermia induced in mice by enzyme-mediated depletion of serotonin

Injection of a purified serotonin (and tryptophan)-degrading enzyme into mice produced a pronounced hypothermia when the mice were maintained at 22 degrees C, but not at 30 degrees C. Brain levels of serotonin and tryptophan were strikingly depleted, but concentrations of norepinephrine and dopamine remained unchanged.     

Hypothermia induced in mice by enzyme-mediated depletion of serotonin

Summary Injection of a purified serotonin (and tryptophan)-degrading enzyme into mice produced a pronounced hypothermia when the mice were maintained at 22°C, but not at 30°C. Brain levels of serotonin and tryptophan were strikingly depleted, but concentrations of norepinephrine and dopamine remained unchanged.This investigation was supported by grants CA-18844 and CA-08748 awarded by the National Cancer Institute, DHEW. We thank Barbara Morelli and Margaret Costello for their technical assistance.     

Dominant lethal mutations induced by14C in mice

Summary The mutagenic potential of 1.0 Ci¹⁴C was evaluated in Swiss albino male mice by the dominant lethal assay. A significant increase in post-implantation loss was seen, the maximum being in the 3rd week after treatment.Authors express their thanks to University Grants Commission, New Delhi, for financial assistance.     

Modulation of 3-hydroxy-3-methyl glutaryl CoA reductase by 2,3-diphosphoglyceric acid

Summary Rat liver microsomal 3-hydroxy-3-methylgularyl CoA (HMG-CoA) reductase was activated by 50% at a concentration of 0.4 mM 2,3-diphosphoglyceric acid (DPG) and by 11-fold at 10 mM DPG. DPG also prevented the inactivation of HMG-CoA reductase by ATP and Mg⁺⁺. Rat liver microsomal HMG-CoA reductase prepared in the presence of 1 mM DPG was significantly more active than when prepared in the absence of DPG. Activation of the enzyme by DPG and protection of the enzyme against inhibition by ATP and Mg⁺⁺ by DPG were also observed with solubilized HMG-CoA reductase.This work was supported by Research Award # 697 G2-1 from the American Heart Association, Greater Los Angeles Affiliate, and by grant # 1R01 HL22672 from the National Institutes of Health. We thank M. Brun and M. Curtis for their excellent technical assistance.     

Modulation of 3-hydroxy-3-methyl glutaryl CoA reductase by 2,3-diphosphoglyceric acid

Rat liver microsomal 3-hydroxy-3-methylglutaryl CoA (HMG-CoA) reductase was activated by 50% at a concentration of 0.4 mM 2,3-diphosphoglyceric acid (DPG) and by 11-fold at 10 mM DPG. DPG also prevented the inactivation of HMG-CoA reductase by ATP and Mg++. Rat liver microsomal HMG-CoA reductase prepared in the presence of 1 mM DPG was significantly more active than when prepared in the absence of DPG. Activation of the enzyme by DPG and protection of the enzyme against inhibition by ATP and Mg++ by DPG were also observed with solubilized HMG-CoA reductase.     

Induction of active immune state by multinucleate tumour cells in mice

Résumé Une immunité active au sarcome, produit par le cholanthrène de méthyle, a été obtenue en utilisant des cellules tumorales multinucléées, associées au virus de Sendai; les réactions ont été spécifiques à la tumeur. A la suite de ces injections, plus de 70% des souris furent résistantes aux trois inoculations, avec 10⁵ cellules vivantes tumorales.     

On the synthesis and structure of 4-hydroxy-3-phenyl-coumarins and related 2-imides

Zusammenfassung Die Einwirkung von Pyridin-Hydrochlorid aufo-Methoxybenzoylbenzylcyanid (I) liefert über entsprechende 2-Imide (IV) die entmethylierten 4-Hydroxy-3-phenyl-cumarinderivate, denen auf Grund der IR.-Spektren Isoflavonstruktur (VII) zuzuordnen ist.      

Circling behavior induced by phencyclidine in mice and its inhibition by naloxone

Phencyclidine (PCP), when given to mice, induces general hyperactivity and rapid circling, similar to that caused by morphine. These effects are partially antagonized by naloxone.     

Circling behavior induced by phencyclidine in mice and its inhibition by naloxone

Summary Phencyclidine (PCP), when given to mice, induces general hyperactivity and rapid circling, similar to that caused by morphine. These effects are partially antagonized by naloxone.Acknowledgment. We are grateful to Professor A. Kalir for the donation of PCP. Correspondence and reprint requests should be addressed to A. M. Korczyn.     

Noise induced convulsions in mice

Zusammenfassung Es wird die Anzahl der Krampfanfälle bestimmt, die durch intensiven niederfrequenten (135 db, 300–4800 Hz) und hochfrequenten (132 db, 2–40 kHz) Schall bei Mäusen ausgelöst werden. Die Krampfschwelle ist bei hohen Frequenzen wesentlich geringer als bei niedrigen. Dieses Ergebnis stimmt mit Berichten, dass die optimale Sensitivität von Nagetieren bei 12–25 kHz liegt, überein.