Intracellular [Ca2+] and K+ and Cl- efflux responses in submandibular cells of neonatal and adult rats.
The effects of graded doses (5 x 10(-8) to 10(-5)) acetylcholine on intracellular Ca2+ and on 86Rb and 36Cl efflux were compared in submandibular cell clusters of 1 and 7 day-old and adult rats. Initial Ca2+ peaks were similar at agonists concentrations lower than 10(-7) M but the release of Rb+ and Cl- were smaller in cells of young animals. At higher agonist concentrations, Ca2+ peaks were higher in immature cells; however, initial Cl- (but not Rb+) efflux was similar to that of mature cells. Plateau Ca2+ levels were independent of age and agonist concentrations but the content of Cl- and Rb+ varied greatly and differences between age groups were less evident. These data confirm a dissociation between intracellular Ca2+ levels and Ca(2+)-mediated ion transport in immature salivary cells.
Seagrave
J C
JC
Lovelace Medical Foundation, Center for Basic and Applied Medical Research, Albuquerque, NM 87106.
Ramsey
R C
RC
Barker
S
S
Martinez
J R
JR
D000109:Acetylcholine / Q000494:pharmacology; D000375:Aging; D000818:Animals; D000831:Animals, Newborn; D002118:Calcium / Q000378:metabolism*; D002712:Chlorides / Q000378:metabolism*; D005470:Fluorometry; D016257:Fura-2; D011868:Radioisotopes / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012414:Rubidium Radioisotopes / Q000378:metabolism; D013363:Submandibular Gland / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D013997:Time Factors
D002712:Chlorides; D011868:Radioisotopes; D012414:Rubidium Radioisotopes; D000109:Acetylcholine; D002118:Calcium; D016257:Fura-2