Carrier Mechanisms

Author(s):  
W. Wilbrandt
Keyword(s):  
1960 ◽  
Vol 37 (3) ◽  
pp. 594-608
Author(s):  
R. H. STOBBART

1. The net transport of sodium into the haemolymph by sodium-deficient 4th-instar larvae of Aëdes aegypti (L.) has been studied by means of flame photometry. The fluxes associated with this net transport have been studied by means of 22Na. 2. The net transport is much more rapid in fed larvae (rate about 50 mM./l./hr.) than in starved larvae (rate about 10 mM./l./hr.). The fluxes are also much greater in the fed larvae. 3. The fluxes associated with net transport in fed and starved larvae are much greater (initially at any rate) than the fluxes occurring in normal fed and starved larvae during steady-state exchange. 4. In both fed and starved larvae almost all the net transport and the fluxes associated with it occur through the anal papillae, so these organs must be responsible for almost all the difference between fed and starved larvae in the rate of net transport and fluxes. 5. Cytological changes in the anal papillae following upon feeding and starvation are described. 6. The results are discussed in terms of possible carrier mechanisms in the anal papillae.


2021 ◽  
Vol 11 (2) ◽  
pp. 884
Author(s):  
Gabrielė Balčiūnaitė-Murzienė ◽  
Mindaugas Dzikaras

Wheat germ agglutinin is a hevein class N-Acetylglucosamine–binding protein with specific toxicity and biomedical potential. It is extractable from wheat germ—a low-value byproduct of the wheat industry—using well–established extraction methods based on salt precipitation and affinity chromatography. Due to its N-Acetylglucosamine affinity, wheat germ agglutinin exhibits antifungal properties as well as cytotoxic properties. Its anticancer properties have been demonstrated for various cancer cells, and toxicity mechanisms are well described. Wheat germ agglutinin has been demonstrated as a viable solution for various biomedical and therapeutic applications, such as chemotherapy, targeted drug delivery, antibiotic-resistant bacteria monitoring and elimination. This is performed mostly in conjunction with nanoparticles, liposomes, and other carrier mechanisms via surface functionalization. Combined with abundant wheat byproduct sources, wheat germ agglutinin has the potential to improve the biomedical field considerably.


1959 ◽  
Vol 36 (4) ◽  
pp. 641-653
Author(s):  
R. H. STOBBART

1. The steady-state exchange of sodium in the 4th instar larva of Aëdes aegypti (L.) has been studied by means of flame photometry and 22Na. 2. The steady-state exchange of sodium between the larva and medium is more rapid in fed larvae (T½ about 10 hr.) than in starved larvae (T½ about 60 hr.). There is no difference between the sodium levels of fed and starved larvae. 3. In both fed and starved larvae about 90% of the exchange occurs through the anal papillae so these organs must be responsible for about 90% of the difference between fed and starved larvae in the rate of exchange. 4. Cytological changes in the anal papillae following upon feeding and starvation are described. 5. The results are discussed in terms of possible carrier mechanisms in the anal papillae.


1963 ◽  
Vol 205 (5) ◽  
pp. 1019-1024 ◽  
Author(s):  
E. C. Foulkes

A technique is proposed and tested which permits the calculation of the size and turnover rate of the p-aminohippurate (PAH) secretory pool in the renal cortex of the rabbit in vivo. The secretory pool is here defined as the cellular solute compartment with which secreted solute equilibrates during its transcellular movement from plasma into tubular urine. The calculations are based on the rate of isotopic equilibration of plasma and urine under steady-state conditions. From the influence of various drugs on the characteristics of the secretory pool, it is inferred that 1) similar PAH carrier mechanisms mediate influx into, and outflux from, the secretory pool, and 2) the PAH accumulated within the cells is coextensive with the secretory pool and is present in a free rather than bound form.


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