PROSTAGLANDINS FOR USE IN THE PROPHYLAXIS, TREATMENT OR DIAGNOSIS OF PULMONARY HYPERTENSION

The present invention is concerned with the use of a compound of formula (I) wherein -W- is selected from where a is 0 or 1, U is hydrogen or halogen and Z is -V(CH2)b-CO2H where b is an integer of from 1 to 3 and V is oxygen or methylene; X is hydrogen, methyl, halogen, cyano, or -C IDENTICAL CH; Y is oxygen, methylene, - N=, or -N(Ar)- where Ar is an optionally substituted phenyl group; R is -(CH2)5R where R is hydrogen or methyl, or R is cyclohexyl, or R is -CH(CH3)CH2C IDENTICAL CCH3; R1 is hydrogen or methyl; and the dotted lines represent independently optional double bonds; and physiologically acceptable salts and acid derivatives thereof, in the manufacture of a medicament for the prophylaxis or treatment of pulmonary hypertension and in the manufacture of a diagnostic aid for identifying PPH (primary pulmonary hypertensive) patients having active pulmonary vasoconstriction. Medicaments and diagnostic aids obtained by the use of the invention which may be administered when primary or secondary pulmonary hypertension is indicated are also within the scope of the invention.