Low temperature effects on micro-arthropods

The main features of the cold hardiness strategies adopted by Antarctic terrestrial arthropods (principally Acari and Collembola) are reviewed. These include lethal low temperatures, chill-coma temperature, supercooling ability, cryoprotectants and survival in anoxic conditions.     

Skeletal keratan sulphate structural analysis using keratanase II digestion followed by high-performance anion-exchange chromatography

A semi-quantitative fingerprinting method has been developedfor the structural analysis of skeletal keratan sulphates. Thisinvolves the digestion of the parent keratan sulphate chainswith the enzyme keratanase II (Bacillus sp.), followed by reductionof the resulting oligosaccharides with sodium borohydride andchromatography on a Dionex AS4A-SC column. This column has beencalibrated for the elution positions of 26 previously characterizedoligosaccharides (Brown et al., Biochemistry, 33, 4836–4846,1994; Brown et al., Eur. J. Biochem., 224, 281–308, 1994).The technique permits sample analysis with pulsed electrochemicaldetection (sensitive to     

Immunocytochemical localization of angiotensin-(1–7) in the rat forebrain

Recent findings by this group have led us to reconsider the view that amino (N−) terminal fragments of angiotensin (Ang) II are inactive degradation products of renin-angiotensin system. To further examine this possibility, an antibody to Ang-(1–7), the N-terminal heptapeptide, was produced to demonstrate the neuroanatomical distribution of the rat brain. Ang-(1–7)-immunoreactivity was found in paraventricular, supraoptic, and suprachiasmatic nuclei, bed nucleus of the stria terminalis, substantia innominata, median eminence, and neurohypophysis. This distribution of Ang-(1–7) in the rat forebrain, together with our previous demonstrations of vasopressin secretion in response to this peptide, suggest that Ang-(1–7) functions as a neuromodulator.     

Two new tryptophane metabolites of the American cockroach

In the course of attempts to isolate and characterize the ‘nesting’ or aggregation pheromone of the American cockroach, Periplaneta americana, two metabolites of tryptophane have been identified. These are oxindole and hydrocarbostyril. That these were indeed tryptophane metabolites was demonstrated by administering radiolabelled tryptophane to cockroaches following tetracycline treatment and isolating the radioactive metabolites.     

One of the protein components of lens fibre membranes is glyceraldehyde 3-phosphate dehydrogenase

The chloroplast envelope contains an acyl-CoA synthetase and an acyl-CoA thioesterase which are associated with the outer and inner membrane, respectively.