biochemical characteristics of α-amylase in the digestive system and head glands of cryptolaemus montrouzieri, a key predator of citrus mealybug, planococcus citri (pseudococcidae), were studied. the major isoform of α-amylase with the same molecular weight was detected in both gut and head glands loaded on polyacrylamide-starch gel electrophoresis. moreover, a minor band with much lower intens...

Rat liver basolateral plasma membrane (blLPM) vesicles resuspended in 5 mM Mg2(+)-, Ca2(+)-, Mn2(+)- or Co2(+)-containing media exhibited a markedly lower rate of Na(+)-stimulated L-alanine transport. Divalent cation inhibition of L-alanine uptake was dose dependent, and was observed only when the vesicles were pre-loaded with the divalent cations. The presence or absence of the metal ions in t...

Extracellular ATP (ATPo) caused a concentration-dependent lysis of mouse thymocytes. Lysis, as judged by release of the cytosolic enzyme lactate dehydrogenase, was preceded by depolarization of the plasma membrane and by Ca2+ influx. Both Na+ uptake (which sustained plasma membrane depolarization) and Ca2+ influx showed (1) the same dependence on the ATPo concentration; (2) the same nucleotide ...

There is a growing body of evidence implicating the involvement of crustacean hyperglycaemic hormone (CHH) in ionic homeostasis in decapod crustaceans. However, little is known regarding hormonally influenced osmoregulatory processes in terrestrial decapods. As many terrestrial decapods experience opposing seasonal demands upon ionoregulatory physiologies, we reasoned that these would make inte...

The kinetics of the E(2) --> E(1) conformational change of unphosphorylated Na(+),K(+)-ATPase from rabbit kidney were investigated via the stopped-flow technique using the fluorescent label RH421 (pH 7.4, 24 degrees C). The enzyme was preequilibrated in a solution containing 25 mM histidine and 0.1 mM EDTA to initially stabilize the E(2) conformation. On mixing enzyme with NaCl alone, tris-ATP ...

Bakar ima povijesnu ulogu u uzgoju vinove loze. odnosno bakreni sulfat predstavlja prvi fungicid za borbu protiv plamenjače Međutim, osim važnosti bakra kao fungicida, bakar je istovremeno i važan mikroelement. Ima važnu sintezi brojnih enzima aktivnosti molekule klorofila. Na povijesnim vinogradarskim tlima, gdje se tlu nalazi visoka količina nema pojave nedostatka listu Nedostatak često može ...

Sciortino, Christopher M., and Michael F. Romero. Cation and voltage dependence of rat kidney electrogenic Na-HCO3 2 cotransporter, rkNBC, expressed in oocytes. Am. J. Physiol. 277 (Renal Physiol. 46): F611–F623, 1999.— Recently, we reported the cloning and expression of the rat renal electrogenic Na-HCO3 2 cotransporter (rkNBC) in Xenopus oocytes [M. F. Romero, P. Fong, U. V. Berger, M. A. Hed...

Saline administration may change renin-angiotensin-aldosterone system (RAAS) activity and sodium excretion at constant mean arterial pressure (MAP). We hypothesized that such responses are elicited mainly by renal sympathetic nerve activity by beta1-receptors (beta1-RSNA), and tested the hypothesis by studying RAAS and renal excretion during slow saline loading at constant plasma sodium concent...