The development of colonic transport mechanisms in early life: evidence for reduced anion exchange

1988 ◽  
Vol 16 (2-3) ◽  
pp. 213-218 ◽  
Author(s):  
Huw R. Jenkins ◽  
Peter J. Milla
2002 ◽  
Vol 80 (5) ◽  
pp. 483-497 ◽  
Author(s):  
Deborah Sterling ◽  
Joseph R Casey

Bicarbonate is not freely permeable to membranes. Yet, bicarbonate must be moved across membranes, as part of CO2 metabolism and to regulate cell pH. Mammalian cells ubiquitously express bicarbonate transport proteins to facilitate the transmembrane bicarbonate flux. These bicarbonate transporters, which function by different transport mechanisms, together catalyse transmembrane bicarbonate movement. Recent advances have allowed the identification of several new bicarbonate transporter genes. Bicarbonate transporters cluster into two separate families: (i) the anion exachanger (AE) family of Cl–/HCO[Formula: see text] exchangers is related in sequence to the NBC family of Na+/HCO[Formula: see text] cotransporters and the Na+-dependent Cl–/HCO[Formula: see text] exchangers and (ii) some members of the SLC26a family of sulfate transporters will also transport bicarbonate but are not related in sequence to the AE/NBC family of transporters. This review summarizes our understanding of the mammalian bicarbonate transporter superfamily.Key words: bicarbonate transport, anion exchange, pH regulation, sodium/bicarbonate co-transport, chloride/bicarborate exchange, carbonic anhydrase.


Author(s):  
Jared Grantham ◽  
Larry Welling

In the course of urine formation in mammalian kidneys over 90% of the glomerular filtrate moves from the tubular lumen into the peritubular capillaries by both active and passive transport mechanisms. In all of the morphologically distinct segments of the renal tubule, e.g. proximal tubule, loop of Henle and distal nephron, the tubular absorbate passes through a basement membrane which rests against the basilar surface of the epithelial cells. The basement membrane is in a strategic location to affect the geometry of the tubules and to influence the movement of tubular absorbate into the renal interstitium. In the present studies we have determined directly some of the mechanical and permeability characteristics of tubular basement membranes.


1973 ◽  
Vol 131 (1) ◽  
pp. 109-114 ◽  
Author(s):  
G. M. Green
Keyword(s):  

2016 ◽  
Vol 86 (1-2) ◽  
pp. 36-47 ◽  
Author(s):  
Imen Dridi ◽  
Nidhal Soualeh ◽  
Torsten Bohn ◽  
Rachid Soulimani ◽  
Jaouad Bouayed

Abstract.This study examined whether perinatal exposure to polluted eels (Anguilla anguilla L.) induces changes in the locomotor activity of offspring mice across lifespan (post-natal days (PNDs) 47 – 329), using the open field and the home cage activity tests. Dams were exposed during gestation and lactation, through diets enriched in eels naturally contaminated with pollutants including PCBs. Analysis of the eel muscle focused on the six non-dioxin-like (NDL) indicator PCBs (Σ6 NDL-PCBs: 28, 52, 101, 138, 153 and 180). Four groups of dams (n = 10 per group) received either a standard diet without eels or eels (0.8 mg/kg/day) containing 85, 216, or 400 ng/kg/day of ϵ6 NDL-PCBs. The open field test showed that early-life exposure to polluted eels increased locomotion in female offspring of exposed dams but not in males, compared to controls. This hyperlocomotion appeared later in life, at PNDs 195 and 329 (up to 32 % increase, p < 0.05). In addition, overactivity was observed in the home cage test at PND 305: exposed offspring females showed a faster overall locomotion speed (3.6 – 4.2 cm/s) than controls (2.9 cm/s, p <0.05); again, males remained unaffected. Covered distances in the home cage test were only elevated significantly in offspring females exposed to highest PCB concentrations (3411 ± 590 cm vs. 1377 ± 114 cm, p < 0.001). These results suggest that early-life exposure to polluted eels containing dietary contaminants including PCBs caused late, persistent and gender-dependent neurobehavioral hyperactive effects in offspring mice. Furthermore, female hyperactivity was associated with a significant inhibition of acetylcholinesterase activity in the hippocampus and the prefrontal cortex.


2020 ◽  
Vol 134 (3) ◽  
pp. 222-232
Author(s):  
Khulganaa Buyannemekh ◽  
Jessica B. Zito ◽  
Michelle L. Tomaszycki

2019 ◽  
Vol 133 (1) ◽  
pp. 50-58 ◽  
Author(s):  
Nathalie D. Elliott ◽  
Rick Richardson

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