CCK Agonists II

A method for stimulating contraction of the gall bladder comprising administering an effective amount of the synthetic peptide having the formula:

• X--R.sub.0 --R.sub.1 --Tyr(Y)--R.sub.3 --R.sub.4 --Trp--R.sub.6 --R.sub.7 --R.sub.8 --NHQ wherein X is H, Suc, Ac, Oxa, Mal, Glt, Prp, Prl or Acr;
• R.sub.0 is Gln, pGlu, Cys, Tyr, Tyr(OCH.sub.3), des--NH.sub.2 --Tyr or desR.sub.0 ;
• R.sub.1 is Asp, Tyr(OH or SE), Ser(OH or SE), Hyp(OH or SE), Thr(OH or SE), Cys, Tyr(OCH.sub.3) or desR.sub.1 ;
• Y is OH or SE;
• R.sub.3 is Met, Nva or Nle;
• R.sub.4 is D--Cys or D--Ala;
• R.sub.6 is Met, Nva or Nle;
• R.sub.7 is Asp, Ser(SE), Thr(SE) or Hyp(SE);
• R.sub.8 is Phe or Tyr(OCH.sub.3);
• and Q is lower alkyl, fluoro lower alkyl or hydrogen;
• provided that either Y is SE or R.sub.7 is other than Asp;
• or a pharmaceutically acceptable salt thereof.

A method of counteracting convulsions in an animal comprising administering an effective amount of a synthetic peptide having the formula:

• X--R.sub.0 --R.sub.1 --Tyr(Y)--R.sub.3 --R.sub.4 --Trp--R.sub.6 --R.sub.7 --R.sub.8 --NHQ wherein X is H, Suc, Ac, Oxa, Mal, Glt, Prp, Prl or Acr;
• R.sub.0 is Gln, pGlu, Cys, Tyr, Tyr(OCH.sub.3), des--NH.sub.2 --Tyr or desR.sub.0 ;
• R.sub.1 is Asp, Tyr(OH or SE), Ser(OH or SE), Hyp(OH or SE), Thr(OH or SE), Cys, Tyr(OCH.sub.3) or desR.sub.1 ;
• Y is OH or SE;
• R.sub.3 is Met, Nva or Nle;
• R.sub.4 is D--cys or D--Ala;
• R.sub.6 is Met, Nva or Nle;
• R.sub.7 is Asp, Ser(SE), Thr(SE) or Hyp(SE);
• R.sub.8 is Phe or Tyr(OCH.sub.3);
• and Q is lower alkyl, fluoro lower alkyl or hydrogen;
• provided that either Y is SE or R.sub.7 is other than Asp;
• or a pharmaceutically acceptable salt thereof.