What you want to do doesnt sound particularly good and maybe you should think about re-designing those 2 procs. However, you could do something like this as a quick fix:
get your sp2 sproc to write it's intermediate results to a temporary table which you can then access/process inside of sp1. You can then drop the temporary table which you created in sp2 once sp1 returns.
http://pastie.org/883881
delimiter ;
drop procedure if exists foo;
delimiter #
create procedure foo()
begin
create temporary table tmp_users select * from users;
-- do stuff with tmp_users
call bar();
drop temporary table if exists tmp_users;
end #
delimiter ;
drop procedure if exists bar;
delimiter #
create procedure bar()
begin
-- do more stuff with tmp_users
select * from tmp_users;
end #
delimiter ;
call foo();
not very elegant but should do the trick