Prolactin and Dexamethasone Regulate Second Messenger-Stimulated Cl⁻ Secretion in Mammary Epithelia

Figure 1

((a1) and (a2)) effect of ATP on [Ca²⁺]_i in control and prolactin and/or dexamethasone-treated HC-11 cells. (a1) Representative tracing shows changes of 100 μM ATP-evoked [Ca²⁺]_i in control (C) and 24 h 1 μg/mL prolactin + dexamethasone-treated (1 μg/mL) (P-D) cells. [Ca²⁺]_i changes were detected from fluorescent intensity of Fluo-3 under confocal microscopy. Data are presented relative to the pretreatment, baseline level. (a2) [Ca²⁺]_i changes were calculated as area under curve for (C), prolactin alone (P 1 μg/mL), dexamethasone alone (1 μg/mL) or P-D cells as described in Section 2. Data are mean ± SEM, 𝑛=4, where each n value represents the mean of 39–44 cells from one dish. ((b1) and (b2)) effect of prolactin and/or dexamethasone treatment on SPCA2 (b1) and TRPC3 (b2) mRNA expression. HC-11 cells were pre-treated with 1 μg/mL prolactin (P) and/or 1 μg/mL dexamethasone (D) for 24 h. Total RNA was extracted, and realtime PCR was performed. L19 was used as internal control. C = control. Data are mean ± SEM, 𝑛=3 for SPCA and 𝑛=4 for TRPC3. *𝑃<0.05 and ***𝑃<0.001 versus control.