Prostaglandin F2 alpha modulates responses of single cultured mesangial cell to arginine vasopressin.
The role of prostaglandin F2 alpha (PGF2 alpha) interaction with arginine vasopressin (AVP) in modulating intracellular Ca2+ homeostasis was studied. Examinations were done on single cultured mesangial cells loaded with fura-2. Pretreatment of cultured mesangial cells during 1 min with different concentrations of PGF2 alpha (10(-5)-10(-8) M) caused a significant prolongation of [Ca2+]i transients after subsequent AVP applications. The observed effect of a prolonged sustained phase was not influenced by the temporal sequence of AVP stimulation after preincubation with PGF2 alpha: the signal was modulated in nearly the same way after 5 min delay as after nearly simultaneous application of AVP and PGF2 alpha. Measurements in Ca(2+)-free medium showed that the prolonged sustained phase of [Ca2+]i transients after AVP applications in cells pretreated with PGF2 alpha was mostly due to Ca2+ release from intracellular store(s). Pretreatment of the cells with PGF2 alpha also greatly enhanced the % of AVP responsive cells. Even at concentrations of AVP as low as 10(-10) M about 30% of cells pretreated with PGF2 alpha responded with the fast [Ca2+]i rise. Thus, present studies showed that PGF2 alpha specifically modulates [Ca2+]i transients after AVP stimulation and enhances sensitivity of mesangial cells to AVP. The results help to identify PGF2 alpha participation in the cellular regulatory mechanisms of microcirculation and filtration in the kidney.
Gabrilevskaya
O V
OV
I. Physiologisches Institut der Universität Heidelberg, Germany.
Vogel
J
J
Nobiling
R H
RH
D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D003470:Culture Media / Q000494:pharmacology; D015237:Dinoprost / Q000494:pharmacology*; D004357:Drug Synergism; D005920:Glomerular Mesangium / Q000166:cytology / Q000187:drug effects*; D008297:Male; D051381:Rats; D017208:Rats, Wistar
D003470:Culture Media; D001127:Arginine Vasopressin; D015237:Dinoprost; D002118:Calcium