The Influence of Verapamil on Calcium Transport and Uptake in Segments of Rat Intestine

Abstract

The effects of verapamil on calcium transport and uptake in duodenal and jejunal segments of intestine in young male rats were determined using the everted gut-sac technique. Verapamil added to both the mucosal and serosal surface of duodenal segments decreased calcium transport and tissue uptake in a dose-related fashion over a concentration range of 1–2 mM. In jejunal segments verapamil (1 mM) added to both the mucosal and serosal surface reduced calcium transport but did not alter tissue uptake. Similarly, verapamil (1 mM) added to either the mucosal or serosal surface alone in duodenal segments reduced transport but did not depress tissue uptake. The results of this study indicate that verapamil alters calcium translocation in intestinal tissue in a fashion which is similar to that reported in other biological tissue.

Endurance swimming stimulates transepithelial calcium transport and alters the expression of genes related to calcium absorption in the intestine of rats

“…Because of a strong correlation between transcellular calcium flux and L-type Ca v activity (40) as well as inhibition of the intestinal calcium absorption by the L-type Ca v blocker verapamil (45), the altered Ca v expression, in addition to TRPV5 and TRPV6, could partially explain the swimming-enhanced duodenal calcium transport. Upregulation of parvalbumin by approximately sixfold (Supplemental Table S2) may also help facilitate the cytoplasmic calcium translocation in the duodenal cells, similar to calbindin-D 9k (6).…”

“…After a 20-min incubation in the Ussing chamber, the tissue was bathed on both sides with fresh bathing solution. One side was 45 CaCl2-containing bathing solution (initial amount of 5 mCi/ml, final specific activity of ϳ450 -500 mCi/mol, Amersham, Buckinghamshire, UK; cold calcium concentration of 1.25 mmol/l). The transepithelial calcium flux (J H3 C) from the hot side (H) to the cold side (C) was calculated by Equations 1 and 2.…”

“…Radioactivity of 45 Ca was analyzed by liquid scintillation spectrophotometry (model Tri-Carb 3100TR; Perkin-Elmer, Boston, MA). Total calcium concentration of the bathing solution was analyzed by atomic absorption spectrophotometry (model SpectrAA-300; Varian Techtron, Springvale, Australia).…”

Luminal glucose does not enhance active intestinal calcium absorption in mice: evidence against a role for Cav1.3 as a mediator of calcium uptake during absorption

“…First, some studies have shown that pharmacologic inhibition of L-type channels reduced Ca absorption in perfused rat jejunal loops [17, 26] or everted intestinal sacs [27, 28]. However, other studies show inconsistent [29, 30] or no effects of L-type channel inhibitors on intestinal Ca absorption [31, 32].…”

Calcium absorption and excretion in patients treated with verapamil.

“…Experiments on rats have shown that verapamil reduces the in vitro intestinal uptake of calcium (Wrobel & Michalska, 1977;Sjoden et al, 1983;Pento & Johnson, 1983), while the intestinal absorption of calcium in vivo is enhanced (Goligorsky et al, 1984). Because After a period of at least 3 weeks without drug treatment, serum and single urine specimens were obtained from the patients after overnight fast.…”