Democratic state Rep. Carl Sciortino today announced a bid for Massachusetts’ 5th District seat.

“I am really proud of the progressive leadership that Ed Markey has brought to our district, and I’m looking forward to continuing that leadership in Washington for communities here,” Sciortino said in a telephone interview with CQ Roll Call.

Rep. Edward J. Markey currently serves the safely Democratic 5th District, which includes suburbs to the north and west of Boston. Markey is the frontrunner in the Senate special election.

Sciortino cited “equality, reproductive health and the future of our environment” as issues that he is focused on and would emphasize if he gets to Capitol Hill.

Sciortino first ran for state representative in 2004 at age 25. The race pivoted on same-sex marriage, which the openly gay Sciortino supports. He faced an incumbent who opposed it. After a hard-fought race, Sciortino won the primary by 93 votes. He took office in 2005 and has been re-elected ever since.

Democrats name a number of other ambitious Bay State politicos in the Legislature who are looking at the 5th District race, including state Sens. Karen Spilka, Katherine Clark and Will Brownsberger.

“Yes, Ed Markey is running for Senate: I’m supporting strongly for that seat,” Brownsberger said in a voicemail left for CQ Roll Call. “If he’s successful, I will run, in turn, for his seat.”

Markey will face Rep. Stephen F. Lynch in the April 30 Democratic primary.

State Rep. Dan Winslow is only declared Republican candidate for the Senate race to fill the seat formerly held by new Secretary of State John Kerry.