Vitamin D status modulates rat colonic M3 muscarinic receptor characteristics and coupling to guanylate cyclase.
The present studies were conducted to determine whether [3H]quinuclidinyl benzilate binding in rat colonic membranes and/or carbachol-mediated stimulation of particulate guanylate cyclase were altered by changes in vitamin D status. EC50 values for the stimulation of colonic guanylate cyclase by carbachol were found to be significantly greater in vitamin D-deficient rats compared to their D-sufficient counterparts. Concomitantly, the density of receptors (Bmax) were significantly lower, and dissociation constants (Kd) were significantly higher in D-deficient colonic membranes. In vitamin D-repleted animals, moreover, all of these aforementioned alterations were at least partially corrected.
Khare
S
S
Department of Medicine, University of Chicago, Hospitals and Clinics, IL 60637.
Tien
X Y
XY
Wilson
D
D
Wali
R K
RK
Bissonnette
B M
BM
Sitrin
M D
MD
Brasitus
T A
TA
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D003106:Colon / Q000378:metabolism*; D003959:Diamines / Q000494:pharmacology; D004789:Enzyme Activation; D006162:Guanylate Cyclase / Q000378:metabolism*; D008297:Male; D018727:Muscarinic Antagonists; D009752:Nutritional Status; D010276:Parasympatholytics / Q000494:pharmacology; D010880:Piperidines / Q000494:pharmacology; D010890:Pirenzepine / Q000494:pharmacology; D011813:Quinuclidinyl Benzilate / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011976:Receptors, Muscarinic / Q000378:metabolism*; D014807:Vitamin D / Q000502:physiology*
D003959:Diamines; D018727:Muscarinic Antagonists; D010276:Parasympatholytics; D010880:Piperidines; D011976:Receptors, Muscarinic; D014807:Vitamin D; D010890:Pirenzepine; D011813:Quinuclidinyl Benzilate; D001285:Atropine; C042375:4-diphenylacetoxy-1,1-dimethylpiperidinium; D006162:Guanylate Cyclase; C054938:methoctramine