The strange saga of Donald R. Manes, the once-jovial pol from Queens, was initially dismissed as a municipal melodrama of minor import.

Mayor Edward I. Koch suggested that the Queens borough president, found nearly dead and bleeding from a slit wrist and ankle 10 days ago, was suffering the disorienting effects of a crash liquid diet. Television commentators raised the possibility of an encounter with a prostitute.

Manes' friends told New York magazine that "a group of Palestinians are stalking Jewish politicians in America."

However, Manes, after telling police last week that he had been kidnaped by two mysterious assailants and hidden in the back seat of his car, said today from his hospital bed that he had tried to commit suicide.

Manes' admission came after disclosures of a bribery investigation involving one of his political proteges, although no connection has been established between his attempted suicide and the probe. This week, federal prosecutors charged Geoffrey G. Lindenauer, a deputy director of the city's parking violations bureau, with extortion. Law enforcement sources say the inquiry will widen.

U.S. Attorney Rudolph Giuliani repeatedly has refused to say whether Manes, the highest elected official in the borough of 1.9 million people, is a target of the investigation.

Giuliani said in an interview last night that "hundreds of thousands of dollars" in bribes have been paid to city officials in the last few years and that his office is investigating "hundreds of millions of dollars in city contracts."

Koch, a close ally of Manes, has moved quickly to reduce any political fallout. On Monday, he named former U.S. attorney John S. Martin to head an in-house probe of all city contracts. "Every aspect of corruption that's humanly possible to be examined will be examined," Koch said. "We want it to be exhaustive."

Koch also canceled a $22.7 million computer contract with a firm partly owned by the Bronx Democratic Chairman Stanley Friedman, a Koch ally. "Unfortunately, we are caught up in other people's scandals," Friedman said, accusing the Koch administration of "acting through the tinted glasses of hysteria" because of "the horrendous publicity."

In an editorial this week, the New York Daily News suggested that the parking probe "may be just the alligator's nose that's poking out of the sewer."

The only charge to date is against Lindenauer, 52, a former psychotherapist who entered city government with ties to the Queens Democratic organization, which has long controlled patronage in the parking violations bureau.

Lindenauer, a $71,046-a-year administrator, is accused of taking $5,000 in cash Nov. 29 from the president of Systematic Recovery Services in the men's room of a posh Japanese restaurant. The company is one of 11 that collect about $45 million a year in delinquent parking fines.

The companies keep up to 60 percent of of their collections. "These are very profitable contracts," Giuliani said. "They are worth a lot of money to the company that gets them."

Giuliani said the investigation began about six months ago as an offshoot of an undercover operation in Chicago involving the same company. Publicity about the investigation in the Chicago Tribune last month blew the secrecy of the New York inquiry, he said.

Giuliani said the investigation will continue, using "traditional methods of interviewing people and analyzing public records."

When Lindenauer was arrested, Koch immediately replaced the director of the parking bureau, Lester N. Shafran. The bureau's counsel, Michael Zapantis, was placed on administrative leave.

Koch said Manes had recently recommended that Lindenauer replace Shafran, who was due to retire as parking bureau director.

An affable, hefty politician -- "Donny" to acquaintances -- Manes is known as "the king of Queens," which is the city's most middle-class borough and would be the country's fifth-largest city if it stood alone. He sits on the city's Board of Estimate, the overseer of capital projects, zoning variances and major contracts. As Queens Democratic leader, he has a powerful hand in judgeships, city patronage jobs and spots on the Democratic ticket.

Manes' predecessor and one-time patron, Matty Troy, was imprisoned for tax evasion and grand larceny in 1976 and 1980. Last month, a veteran Queens judge, Supreme Court Justice William C. Brennan, was convicted of accepting $50,000 in bribes to fix criminal trials.

Saturday night, as Manes lay in the hospital, 800 people, including former vice-presidential nominee Geraldine A. Ferraro, showed up at a $60-a-head party to celebrate his 52nd birthday. "There's a lot of hurting for Donald," Ferraro told a local reporter.

Noting that seven hours passed between the time Manes left a reception for the Israeli consul and the time he was found by police at 1:50 a.m. Jan. 10, Queens District Attorney John Santucci said at a news conference today, "He must give us an explanation of where he was, who he was with and what was the subject discussed."

Manes is not telling.

"The fact that I came to be in a state of mind permitting me to do such a terrible thing to myself is very painful for me to deal with," he said today. "I have talked of my reasons, such as they are, with my wife, my family and the psychiatrist in this hospital who is now helping me. Of course, I also had to discuss the matter fully with my attorney."