Yes, PRESSORS is a Scrabble word!

Letter values in Scrabble US: P 3, R 1, E 1, S 1, S 1, O 1, R 1, S 1.

Is it a valid word?

PRESSORS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

any agent that causes a narrowing of an opening of a blood vessel: cold or stress or nicotine or epinephrine or norepinephrine or angiotensin or vasopressin or certain drugs; maintains or increases blood pressure

Also: vasoconstrictive.