President Carter announced the nomination yesterday of four ambassadors, including David B. Bolen, a career diplomat for 27 years, as ambassador to East Germany.

Bolen, 53, a native of Heflin, La., was ambassador to Botswana, Lesotho and Swaziland in 1973-75 until he became deputy assistant secretary of state for African affairs. He would succeed former Sen. John Sherman Cooper (R-Ky.)

The other ambassadorial nominees, all subject to Senate confirmation, are:

Bulgaria - Dr. Raymond L. Garthoff, 48, of Milford, Conn., a specialist on Soviet affairs for 20 years for the Army, North Atlantic Treaty Organization and the State Department, where he has been a senior Foreign Service inspector since 1974. He would succeed Martin F. Herze.

Nicaragua - Dr. Mauricio Solaun, 42, a native of Cuba, a sociologist at the University of Illinois since 1966. He would replace James D. Theberge.

Guyana - John R. Burke, 52, of Madison. Wis., a State Department Foreign Service officer since 1956 and deputy chief of mission in Bangkok since 1976. The post has been vacant since Max V. Krebs resigned.

Carter also nominated:

John D. Negroponte, 37, a member of the Foreign Service since 1960 and now deputy assistant secretary of state for oceans and fisheries, as an ambassador to represent this country at international conferences on fish and wildlife.