To investigate the relationship between the upregulated expression of sphingosine-1-phosphate receptor 1 (S1P1) in the corpus cavernosum and erectile function in spontaneously hypertensive rats (SHRs).

Twelve-week-old healthy male Wistar-Kyoto rats (WKY) and SHR rats were randomly divided into 4 groups: WKY, SHR, WKY transfection, and SHR transfection (n = 5). A lentiviral vector carrying the S1P1 gene was injected into the corpus cavernosum penis of rats in the transfection groups (1 × 10⁹ TU/mL, 20 μL). After 1 week, the maximum penile intracavernous pressure/mean arterial pressure (ICP_max/MAP), nitric oxide (NO) content, and the expression of eNOS, P-eNOS, ROCK1, ROCK2, and S1P1 in the corpus cavernosum penis of rats in each group were measured.

The ICP_max/MAP value was significantly higher in the SHR transfection group than in the SHR group under 3-V and 5-V electrical stimulations (P <.01). The expression of S1P1 and P-eNOS proteins significantly increased (P <.01), while that of ROCK1 and ROCK2 proteins significantly decreased (P <.01) in the SHR transfected group compared with the SHR group. The NO content was significantly higher in the SHR transfection group than in the SHR group (P <.01).

The upregulated expression of S1P1 in SHR corpus cavernosum penis may improve the SHR erectile function by upregulating the P-eNOS/eNOS ratio and inhibiting the RhoA/Rho kinase signaling pathway.