Figure 12.

Effects of SM-specific deletion of Ca_v1.2 on popliteal lymphatic contractile function. (A) Contractile patterns in a PL from a Ca_v1.2 floxed mouse (without Cre) after tamoxifen administration 12 days prior to the experiment. Contraction patterns are essentially identical to those of PLs from WT mice (See Fig. 6A). (B) Complete absence of large-amplitude, propulsive contractions in a PL from a SM-specific Ca_v1.2 KO mouse. The vessel exhibits only very small amplitude vasomotion, which is mostly independent of the pressure level. (C) Expanded y-axis scale showing the vasomotion pattern in another PL from a SM-specific Ca_v1.2 KO mouse. (D–G) Summary of contractile parameters for Ca_v1.2^fl/fl (control) and SMMHC-Cre^ERT2; Ca_v1.2^fl/fl mice studied 10–12 days after tamoxifen administration. With one exception all parameters at all pressures were significantly different between the two groups. The exception was tone at 0.5 cmH₂O. Note that tone in SM-specific Ca_v1.2 KO vessels is ~3-fold higher than in the corresponding Ca_v1.2 floxed controls at every pressure except 0.5 cmH₂O.