Rat renal cell monolayer culture: A sensitive method for investigating ADH and PTH actions on the kidney by determining adenosine 3':5'-cyclic monophosphate.

Abstract

The response of cAMP to antidiuretic hormone (ADH) was studied using rat renal medullary cells in a monolayer culture. cAMP response to parathyroid hormone (PTH) was studied in renal cortical cells. As the culture aged, an increase in basal cAMP content and a gradual decrease in the cAMP responsiveness to arginine vasopressin (AVP) were observed. After 2 days of culture, AVP and h[human]PTH-(1-34) produced a rapid increase in intracellular cAMP with single peaks, after 10 min and 5 min, respectively. Extracellular cAMP was increased linearly by both AVP and hPTH-(1-34). The response of cAMP to AVP was markedly greater in the medulla than in the cortex, while the response to hPTH-(-34) was remarkable only n the cortex. Outstanding sensitivity of cAMP responsiveness was observed in this sytem, i.e., 10-12 M AVP (1 pg/ml) and 2.43 .times. 10-10 M hPTH-(1-34) (1 ng/ml) provoked significant increases in cAMP from the basal level of 0.31 .+-. 0.04 and 0.59 .+-. 0.05 pmol/dish to 0.79 .+-. 0.03 and 1.07 .+-. 0.13 pmol/dish, respectively (P < 0.001). In the medulla, potencies of lysine vasopressin (LVP), DDAVP [1-deamino-8-D-arginine vasopressin] and oxytocin at a concentration fo 10-9 M were 76.1%, 154.2% and 8.1% of that of AVP, respectively. Apparently, this system provides a useful tool for investigating the mechanism of hormone actions on the kidney at physiological concentrations.