Helospectin II, a member of the vasoactive intestinal peptide (VIP) family, exhibits vasodilatory and antihypertensive properties that reduce blood pressure. This neuropeptide was initially isolated from the venom of the salivary glands of the Heloderma suspectum lizard [1] [2].

It appears that there is some text missing from your request, as the sentence 'Helospectin II (suffusion at 0.' is incomplete. This does not give a full description of the activity of the chemical compound. Could you please provide the full sentence or additional context that describes the activity of Helospectin II? Once I have the complete sentence, I would be happy to rewrite it in Chinese and improve its clarity and conciseness as you requested.

Helospectin II（剂量范围0.03-2 nmol/kg，左颈静脉注射100 μL）可降低大鼠血压[2]。