Four of the five senators under investigation for ties to savings and loan executive Charles H. Keating Jr. made impassioned and sometimes combative defenses of their actions yesterday, arguing that they did nothing wrong. Two said they did nothing more than other members of the Senate in helping constituents and political contributors.

One by one, Sens. John McCain (R-Ariz.), John Glenn (D-Ohio), Alan Cranston (D-Calif.) and Donald W. Riegle (D-Mich.) told the Select Committee on Ethics that they had complied with existing Senate rules in their dealings with Keating. Sen. Dennis DeConcini (D-Ariz.), who repeatedly has denied any improprieties, is expected to repeat those denials when the hearings continue Monday.

To illustrate his contention that fund-raising is closely tied to official Senate business, Cranston brought in five huge charts -- readable to the television audience -- listing the staff members that every senator has designated to raise campaign funds.

"Let me ask you this, members of the committee," Cranston said. "How many of these Senate staffers who are legally empowered to raise money do you think have sat in meetings with their senator and contributors, potential or proven, when substantive issues were discussed, like problems with bureaucrats and legislation? How many of you . . . could testify that some member of your Senate staff who you have authorized to raise money has never ever said to you something like, 'John Doe is coming in and about to meet with you, and I'll sit in; here's what I think you ought to do -- and, remember, he's been a big help to you' ?"

"I say that it's absurd to suggest that fund-raising and substantive issues are separated in Senate offices by some kind of wall."

Known as the "Keating Five," the five senators are being investigated for their intervention with federal regulators on behalf of Keating and his failing Lincoln Savings and Loan Association of Irvine, Calif., during a period in which Keating raised more than $1.3 million for their campaigns and causes. The collapse of Lincoln is expected to cost taxpayers at least $2 billion.

The senators opened their defense after special committee counsel Robert S. Bennett, winding up his presentation of findings from a year-long investigation, charged that Cranston actively solicited money from Keating while Keating was seeking his help in dealings with federal thrift regulators.

Cranston's official intervention on Keating's behalf was "closely connected" with the money Keating raised for him, including $49,000 in campaign contributions, $850,000 for three voter-registration groups controlled by Cranston and a $300,000 line of credit for campaign use that was never used, Bennett contended.

Bennett, who outlined his case against the other four senators on the first day of hearings Thursday, said Cranston was the only one of the five who personally solicited Keating for contributions by the thrift entrepreneur, now facing trial in California on junk-bond fraud charges.

On four occasions Cranston "accepted or solicited several hundred thousand dollars" for voter registration groups with which he was associated, and "each of these four occasions was linked by time and circumstance to a request by Mr. Keating for assistance," Bennett told the panel.

At one point, Bennett quoted Cranston as saying in a deposition taken earlier this year that "a person who makes a contribution has a better chance to get access than someone who does not . . . I'm not going to mislead them {the public} into the belief that every citizen will have an equal opportunity to get at me, because it's not true."

In a highly personal defense of his actions that included references to the prostate cancer he suffers from, the "malicious" attacks on his only living son, Kim, and his "anguish" over seeing his integrity under attack, Cranston said he "engaged in no unethical conduct . . . broke no law . . . broke no Senate rule."

While he did not directly rebut Bennett's charge that he was helping Keating while seeking money from him, Cranston accused Bennett of trying to judge him by rules that do not exist and to single him out for activities that are common to all senators.

In response to Bennett's references to his use of a fund-raiser to meet with Keating on Lincoln's regulatory problems as well as campaign contributions, Cranston noted that Senate rules permit every senator to appoint staff members to solicit and receive campaign contributions. The charts he displayed showed that all six members of the ethics committee have designated fund-raisers on their staffs, including administrative and legislative assistants in the case of committee chairman, Sen. Howell T. Heflin (D-Ala.), and vice chairman, Sen. Warren B. Rudman (R-N.H.).

Cranston's fund-raiser, Joy Jacobson, was not on his Senate staff but has said she attended meetings dealing with Keating's regulatory problems. She also wrote several memos to Cranston in which she discussed Keating as a source of contributions and his requests for assitance in solving his regulatory problems. In a deposition taken earlier this year, Jacobson said she was unaware at the time of the meeting of any relationship between official actions that Cranston took on Keating's behalf and Keating's contributions to him. But, she testified, "in retrospect I think that there was a link there."

In his morning presentation, Bennett read from a January 1987 confidential memo in which Jacobson told Cranston that Keating was among campaign supporters who "rightfully expect" some resolution of pending requests for help from the senator.

In another memo, Jacobson said Keating should be happy with the recent appointment of M. Danny Wall as head of the Federal Home Loan Bank Board and added: "You should ask Keating for 250,000 dollars." Asked why she suggested $250,000, Bennett said Jacobson responded that Cranston had wanted to ask for $500,000.

Riegle joined Cranston in criticizing the current system of campaign financing and cautioned committee members that all senators and candidates will be in "dire jeopardy," unless the rules are changed.

Glenn and McCain, who were largely absolved by Bennett of unethical conduct, told the committee they did nothing improper or illegal. "At no time did I pare my principles or compromise my convictions," said Glenn. McCain said he got involved only to see that "Lincoln was being treated fairly," and, when Keating asked him to do things he regarded as improper, "I said no."

Riegle, choking with emotion at one point, asserted that "there has never been any time and there never will be a time" when he would trade favors for campaign contributions. "I would never in any way I know violate the ethics of this place. I wouldn't do it and nobody could make me do it."

As the hearing began, the committee refused a request from William W. Taylor III, Cranston's attorney, to disqualify Sen. Jesse Helms (R-N.C.), a committee member, because Helms referred to Cranston during his recent reelection campaign as "the leading water carrier in Congress for that S&L kingpin, Charles Keating." Taylor said Cranston was entitled to an assurance of impartiality.

Helms said he made the remark in the context of ads criticizing his record on the savings and loan issue that were aired by his Democratic opponent, Harvey Gantt. Helms said Gantt had received money from a Cranston political action committee to which Keating had contributed.

Michael Davidson, the Senate legal counsel, said committees are not empowered to disqualify members, and the ethics panel, recessing to meet behind closed doors, left the decision up to Helms. Helms refused to disqualify himself.

Staff writer John E. Yang contributed to this report.