Here is how the Latin American debt of an estimated $400 billion is affecting individual nations:

*BRAZIL: Holding the world's largest foreign debt, estimated at $124 billion, Brazil suspended debt payments for one year in February 1987 and is renegotiating refinancing. Labor discontent is widespread because of austerity program needed to satisfy creditors.

*MEXICO: With a debt of $104 billion, Mexico suspended payments on principal in 1982. It is now up to date on payments, but internal belt-tightening measures have been unpopular and threaten to undermine the domination of the ruling Institutional Revolutionary Party, in power since 1929.

*ARGENTINA: Suspended payments on its foreign debt of $56 billion in April 1987. No prospect of getting new financing until after May 14 presidential elections.

*VENEZUELA: President Carlos Andres Perez on March 3 announced suspension of debt payments after rioting, resulting from an austerity plan, led to 260 deaths. Venezuelan authorities are negotiating to refinance debt of $33 billion.

*CHILE: President Augusto Pinochet, using tough measures against dissidents, has kept his nation up to date on payments on a debt of $17.7 billion. Chile has strictly complied with its International Monetary Fund agreements and last year reduced its debt by $1.5 billion.

*PERU: In 1985 President Alan Garcia announced Peru would only pay an amount equivalent to 10 percent of its exports to meet payments on a foreign debt that is now $16.2 billion. The IMF and the Inter-American Development Bank have declared Peru ineligible for new loans.

*COLOMBIA: Usually a good payer, but, because of difficulties in renewing credit, it suspended some interest payments this year on a foreign debt of $16 billion.

*ECUADOR: Suspended payments on its debt of $11 billion in March 1987 for lack of foreign exchange after oil exports were stopped when an earthquake broke a critical pipeline. President Rodrigo Borja is trying to arrange for refinancing.