Iodopyracet (Diodrast) transport by the rabbit eye

1961 ◽  
Vol 200 (3) ◽  
pp. 461-464 ◽  
Author(s):  
Bernard Becker ◽  
Max Forbes
Keyword(s):  
Active Transport ◽  
Ciliary Body ◽  
Metabolic Inhibition ◽  
Renal Tubules ◽  
Rabbit Eye ◽  
Secretory System

Iodopyracet is accumulated by the rabbit ciliary body in vitro and transported out of the living rabbit eye. Both processes resemble the analogous accumulation and active transport by the renal tubules and demonstrate similar competitive and metabolic inhibition. With increasing amounts of iodopyracet in the eye, saturation of the secretory system is demonstrated with a secretory maximum of approximately 1.2 x 10–8 moles/min.

Iodide transport by the rabbit eye

1961 ◽  
Vol 200 (4) ◽  
pp. 804-806 ◽  
Author(s):  
Bernard Becker
Keyword(s):  
Thyroid Gland ◽  
Ciliary Body ◽  
Organic Anions ◽  
Iodide Transport ◽  
Rabbit Eye ◽  
Secretory System

I131 is accumulated by rabbit ciliary body-iris preparations in vitro and transported out of the living rabbit eye. The secretory system resembles the accumulation of iodide by the thiouracil-treated thyroid gland. It is saturated by iodide and inhibited by perchlorate, thiocyanate and fluoroborate. The mechanism for iodide transport out of the rabbit eye appears to be independent of the analogous transport of iodopyracet and related organic anions.

Application of the EYTEX™ System to the Evaluation of Cosmetic Products and their Ingredients

1992 ◽  
Vol 20 (1) ◽  
pp. 146-163
Author(s):  
Francis H. Kruszewski ◽  
Laura H. Hearn ◽  
Kyle T. Smith ◽  
Janice J. Teal ◽  
Virginia C. Gordon ◽  
...  
Keyword(s):  
Double Blind ◽  
Eye Irritation ◽  
Ocular Irritation ◽  
Rabbit Eye ◽  
Wide Range ◽  
High Concentrations ◽  
Alkaline Membrane ◽  
Positive Agreement

465 cosmetic product formulations and raw ingredients were evaluated with the EYTEX™ system to determine the potential of this in vitro alternative for identifying eye irritation potential. The EYTEX™ system is a non-animal, biochemical procedure developed by Ropak Laboratories, Irvine, CA, that was designed to approximate the Draize rabbit eye irritation assay for the evaluation of ocular irritation. Avon Products Inc. provided all the test samples, which included over 30 different product types and represented a wide range of eye irritancy. All the EYTEX™ protocols available at the time of this study were used. Samples were evaluated double-blind with both the membrane partition assay (MPA) and the rapid membrane assay (RMA). When appropriate, the standard assay (STD) and the alkaline membrane assay (AMA) were used, as well as specific, documented protocol modifications. EYTEX™ results were correlated with rabbit eye irritation data which was obtained from the historical records of Avon Products Inc. A positive agreement of EYTEX™ results with the in vivo assay was demonstrated by an overall concordance of 80%. The assay error was 20%, of which 18% was due to an overestimation of sample irritancy (false positives) and 2% was attributed to underestimation (false negatives). Overestimation error in this study was due in part to the inability of the protocols to accurately classify test samples with very low irritation potential. Underestimation of sample irritancy was generally associated with ethoxylated materials and high concentrations of specific types of surfactants. 100% sensitivity and 85% predictability were described by the data, indicating the efficiency of EYTEX™ in identifying known irritants. A specificity rate of 39% showed the EYTEX™ assay to be weak in discerning non-irritants. However, the EYTEX™ protocols used in this study were not designed to identify non-irritants. A compatibility rate of 99% proved the effectiveness of the EYTEX™ assay in accommodating a diversity of product types. The EYTEX™ system protocols, when used appropriately, can provide a conservative means of assessing the irritant potential of most cosmetic formulations and their ingredients.

Pilocarpine hydrochloride liposomes: characterization in vitro and preliminary evaluation in vivo in rabbit eye

1984 ◽  
Vol 1 (3) ◽  
pp. 203-216 ◽  
Author(s):  
S. Benita ◽  
J. D. Plenecassagne ◽  
G. Cavé ◽  
D. Drouin ◽  
P. Le Hao Dong ◽  
...  
Keyword(s):  
Preliminary Evaluation ◽  
Rabbit Eye

In vitro absorption of bile salts by small intestine of rats and guinea pigs

1961 ◽  
Vol 200 (2) ◽  
pp. 313-317 ◽  
Author(s):  
Leon Lack ◽  
I. M. Weiner
Keyword(s):  
Small Intestine ◽  
Bile Acid ◽  
Active Transport ◽  
Sodium Azide ◽  
Concentration Gradient ◽  
Guinea Pigs ◽  
Bile Salts ◽  
Ileal Segment

The transport of taurocholic and glycocholic acids by the small intestine of rats and guinea pigs against a concentration gradient was studied by the everted gutsac technique. Transport of these substances is limited to the distal ileal segment. This transport is inhibited by anoxia, dinitrophenol and sodium azide. The system has a transport maximum. On the basis of these criteria bile acid reabsorption is considered to occur by active transport.

Experimental Cystinuria: the Cycloleucine Model. I. Amino Acid Interactions in Renal and Intestinal Epithelia

1975 ◽  
Vol 53 (6) ◽  
pp. 1027-1036 ◽  
Author(s):  
André G. Craan ◽  
Michel Bergeron
Keyword(s):  
Amino Acids ◽  
Renal Tubules ◽  
Intestinal Epithelia ◽  
Luminal Membrane ◽  
Luminal Side ◽  
Convoluted Tubules ◽  
Dibasic Amino Acids ◽  
Everted Sacs

The injection of cycloleucine (1-aminocyclopentanecarboxylic acid (ACPC)) into rats produces a hyperexcretion of dibasic amino acids and cystine, an aberration resembling cystinuria. This may constitute a model of experimental cystinuria, and the transport of amino acids involved in this disease was studied with the techniques of everted intestinal sacs (in vitro) and microinjections into renal tubules (in vivo). In everted sacs from normal rats, there was a decrease in transfer and in accumulation of L-cystine (0.03 mM), L-lysine (0.065 mM) and L-valine (0.065 mM) when ACPC was on the mucosal (luminal) side. Dibasic amino acids such as L-ariginine and L-lysine caused a similar inhibition of the transport of L-cystine. However, when ACPC was on the serosal (antiluminal) side, a lesser effect was noted while arginine and lysine had no effect. Intestinal sacs from treated rats (ACPC, 300 mg/kg × 3 days) transferred and accumulated as much L-cystine as those from control rats. The interaction between cycloleucine and L-cystine was competitive at the luminal and non-competitive at the antiluminal side of the intestine. Cycloleucine inhibited L-lysine transport in a non-competitive fashion at either side of the intestine. L-Lysine also interacted in a non-competitive fashion with L-cystine transport at the luminal membrane. In proximal convoluted tubules, the presence of L-arginine or ACPC caused a decrease in the transport of L-cystine and L-lysine. L-Valine exerted no effect. Furthermore, L-lysine and ACPC did not impair the reabsorption of L-valine significantly.These results suggest a functional heterogeneity between luminal and antiluminal membranes of renal and intestinal epithelia and the existence, at both membranes, of different transport sites for cystine and dibasic amino acids.

scholarly journals ACTIVE TRANSPORT OF D-GLOUCOSE BY INTESTINAL SEGMENTS IN VITRO, OF ICTALURUS NEBULOSUS ,

1964 ◽  
Vol 126 (2) ◽  
pp. 291-301 ◽  
Author(s):  
X. J. MUSACCHIA ◽  
S. S. NEFF ◽  
D. D. WESTHOFF
Keyword(s):  
Active Transport ◽  
Ictalurus Nebulosus ◽  
Intestinal Segments
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