Regional brush-border uptakes of α-methyl-d-glucose andl-proline as well as morphometric parameters were studied from birth until adulthood in guinea pig small intestine. Intestinal weight, length, and area were fitted to two-segmented straight lines: from birth until the 2nd wk there was a sharp rise, whereas from day 14 to the adult stage the increase was slower. In everted sleeves, total upt...

The herbicidal actioIn of 2,4-dichlorophenoxyacetic acid (2,4-D) has been the subject of many investigations in the years sinice this compound was first demonstrated to be a plant toxicant. Almost as many possible mechanismiis for this toxicityhave been suggested. These includle depletioni of respiratory substrate, abnormal cellular proliferation, the production of toxic substances in response ...

Altlhoughl cutimize(d tissue in some forlmi is the first harrier to the entrv of chemicals into plants, dlirect measurements of the permeability properties of cuticular membranes are limited aandl qualitative (1, 5 ). Froml clirect miieasuremleints oin isolated cuiticle Skoss (9 ) has reported that Eniglish ivy leaf cuticle is relativelv illmpermleable to w ater, aandl that lemloni leaf cuticle...

NIy comments will be confined to aspects of electrode construction or measuring techniquie that liffer from those originally (lescribed by Uhlich, Baldamus, and Ullriclh(l). I wislh to indlicate my deep gratittu(le to these investigators who kin(dly introduce(d me to their elegant method in 1968. The hiiglh impedlance Orion 801 amplifier witlh specially slhielded cables was used for the pH elec...

Influx ofd-aspartate (d-Asp),l-glutamate (l-Glu), and serine (Ser) across the brush-border membrane of the intact mucosa from rabbit ileum has been examined. l-Glu influx is chloride independent and completely sodium dependent.d-Asp andl-Glu share a transport system with a maximum transport rate of 1 μmol ⋅ cm-2 ⋅ h-1and an apparent affinity constant ( K ½) of ∼0.3 mM. The function of this tran...