Uptake of glucose-C14 and fructose-C14 by buffalo spermatozoa in extenders during cold storage

Summary Buffalo spermatozoa exhibit insignificant uptake of glucose-C¹⁴ and fructose-C¹⁴ when semen samples were preserved in cold for 96 h in 2 extenders. Incorporation of C¹⁴ in spermatozoa, TCA precipitable proteins and soluble sugar phosphates was either equal or less in semen samples preserved in cold. CAW appeared to be a better extender than SKMEY as revealed by sugar uptake in cold.Acknowledgment. We are indebted to Dr D. Sundaresan, Director, for his kind encouragement in this study.     

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.     

Open field locomotion by zinc deficient adult male mice

Summary Adult male mice maintained on a zinc-free diet display a statistically significant increase in open field locomotion compared to controls. However, excess zinc (100 times the established recommended daily allowance) does not produce a change compared to controls.     

Structure-activity relationship of various ephedrine isomers on noradrenaline uptake by the isolated perfused rabbit heart]

(-)Ephedrine, (+) Ephedrine, (-) psi ephedrine and (+) psi ephedrine inhibit both the neuronal and extraneuronal uptakes of noradrenaline in isolated Rabbit heart. (-) ephedrine is the most active isomer for the inhibition of both neuronal and extraneuronal uptakes. The relative inhibition potential of the three other isomers is not the same when applied to one or other uptake.     

Isoguvacine,isonipecotic acid,muscimol and N-methyl isoguvacine on the GABA receptor in rat sympathetic ganglia

Summary The GABA-mimetic activities of 4 analogues muscimol, isonipecotic acid, isoguvacine and N-methyl isoguvacine have been examined at the GABA receptor in the rat isolated superior cervical ganglion. The depolarizing action of all 4 analogues could be selectively antagonized by bicuculline methochloride and isopropyl bicyclophosphate. Muscimol was the only analogue more potent than GABA (molar potency ratio=5.08±0.707). The potency of isoguvacine was 0.23±0.026 and isonipecotic acid 0.011±0.0028. N.-methyl isoguvacine was <0.001 GABA.     

Primary liver carcinogenesis induced by the pesticide 2-(4-tert-butylphenoxy0-1-methylethyl 2-chloroethyl sulphite (Aramite)]

Wistar rats were fed, during 56 weeks, a diet containing 5 g/kg of Aramite. At the end of the treatment, all the surviving animals show, on anatomo-pathological examination, malignant proliferation of the hepatic tissue and, in certain cases, of biliary ducts. This compound, proposed in the past as acaricide in agriculture, can thus be considered as a model substance for induction of malignant liver tumors.     

Satellite heterophagosomes

Summary An incidental observation made during a recent ultrastructural study shows that after ingestion of an erythrocyte by a Kupffer cell surface budding occurred from the heterophagosome leading to the formation of smaller satellite or daughter heterophagosomes. It is suggested that an entire erythrocyte may be too large to digest in a single heterolysosome and that fragmentation into smaller units facilitates digestion by bringing about better contact between the enzymes and substrates.Work supported by grants from the Medical Research Council of Canada.