Fluorogenic amines in the notochords of chick embryos treated by cholinergics]

The investigation of 3 day old notochords by the fluorescence method of Falck and Owman showed an increase of the fluorescence after treatment of the chick embryos at 48 hrs of incubation, with nicotine sulfate or carbachol. The addition of norepinephrine or L-Dopa emphasized the formaldehyde induced fluorescence. The simultaneous treatment with a cholinergic agent and atropine, propranolol or reserpine decreased or suppressed the fluorescence. These results demonstrate the existence of a relationship between the treatment with a cholinergic agent and the amount of chordal biogenic amines.     

Neuromuscular blocking activity of dibekacin,a new semisynthetic aminoglycoside antibiotic

Summary Dibekacin possesses the untoward effect of producing a neuromuscular blockade. Neostigmine is unable to reverse the neuromuscular blockade produced by dibekacin. Calcium has not only the ability to restore the neuromuscular transmission but also to exert protective action against the neuromuscular blocking activity of dibekacin.     

Effect of a mitogenic concentration on membrane glycoconjugates of human lymphocytes

Periodate oxidation of human peripheral blood lymphocytes followed by reduction with 3H labelled sodium borohydride and acidic hydrolysis generates N-AN 7, glycerol and propane 1-2 diol. This indicates that sialyl, fucosyl and probably galactosyl residues are oxidized by periodate. Neuraminidase-treated lymphocytes exhibit decreased N-AN 7 levels, increased N-AN 8 levels and increased glycerol levels. Such results were neither found with mouse splenocytes nor with calf lymph node cells.     

The effect of pH and methylation on the interaction of deoxycholate with rat liver alcohol dehydrogenase

Summary The activation of rat liver alcohol dehydrogenase by deoxycholate depends on the anionic form of the steroid. Methylation of the enzyme protein leads to an increase of both turnover number and K_m for ethanol and to a change in the effect of deoxycholate, which behaves as an inhibitor. It is suggested that the steroid and methylation effects depend on the same basic mechanism, in which one or more Lys groups are involved.Acknowledgment. We thank Professor A. Guerritore for his help and advice. This work was supported by a grant from the Italian Consiglio Nazionale delle Ricerche.     

Inhibition of human chlorionic gonadotrophin-induced ovarian and uterine growth in the mouse by synthetic arginine vasotocin-1.

21-day-old Swiss-Webster female mice were injected with 1 IU HCG at 09.00 h. Injection of freshly prepared arginine vasotocin (2 mug/0.1 ml/injection) every 12 h inhibited the HCG-induced hypertrophy of the ovaries at 36, 48, 60 and 72 hr after HCG-treatment while the uterine weight was depressed at 60 and 72 h.     

The effect of heat on rat pineal hydroxyindole-O-methyl transferase activity

Summary Exposure of adult male rats to continuously elevated temperature of 32–34°C caused a significant decrease of HIOMT activity involved in the specific metabolic process of production of melatonin, considered an active pineal hormone. The effect was already evident after 24 h exposure and increased further during the next 48 h. The results obtained substantiate previous data that the pineal gland may be involved in the system regulating adaptation to extreme temperature changes.Acknowledgment. The authors are indebted to MissUte Schmidt for her excellent technical assistance.     

Sectioning of polyacrylamide slab gels with a modified small animal stereotaxic instrument

Summary A simple and inexpensive modification of the Kopf model 900 small animal stereotaxic instrument allows it to be used temporarily as a precision polyacrylamide slab gel slicer.Supported by the Alfred P. Sloan Foundation.