For the past two days, Amy Kaplan, a 40-year-old emergency room nurse and single parent of two teen-age sons, has walked the picket line in front of Greater Laurel-Beltsville Hospital because she says that changes in the nursing profession are long overdue.

Kaplan, one of several hundred registered nurses on strike against three Prince George's County health facilities, said yesterday that she loves her job. Unlike her striking colleagues at Prince George's General Hospital, the county's largest, she is happy with her working conditions but felt obligated to go out on strike to support the other registered nurses, she said. "I had a very difficult time coming to this decision," she added, noting that when it came time for the strike vote last Saturday, she was so nervous that she felt nauseated.

On Monday, about 40 percent of the regularly scheduled registered nurses showed up for work at the Prince George's General and Greater Laurel hospitals and the Bowie Health Center. Hospital officials could not provide a work figure for yesterday.

Union officials said that at least 280 of the 650 nurses at the three facilities have actually walked the picket lines and more have not reported for work. Many have already found other temporary work, union officials said yesterday.

When cars carrying other nurses to work passed the picket lines, some picketers scowled, but few jeered. The striking nurses said they understood that the decision to cross or not to cross the picket line was difficult.

Some of their colleagues inside expressed similar understanding. Several nurses working at Laurel hospital held signs up in windows yesterday encouraging colleagues outside.

Strike coordinator Donna Hutchinson said some decided to join the strikers after their shifts Monday night. "Friends are talking to friends," Hutchinson said.

Other nurses at work, all of whom asked that their names not be used, said that they felt animosity was beginning to develop between themselves and the strikers. One nurse who works on a medical ward and who is a union member said yesterday that her decision not to strike did not stem from a belief that nurses are paid enough. She said she just did not like the idea of going out on strike.

"I don't agree with that way of doing things," she said.

Mike Canning, spokesman for Community Hospitals and Health Systems Inc., the corporation that operates the three health facilities, said yesterday that patients there were being adequately cared for. Supervisory nurses have been working 12-hour shifts and several temporary nurses (called "flying nurses" by the strikers) have been brought in to work, he said. Three of four outpatient clinics at Prince George's General have been closed. Many routine appointments have been canceled and outpatients requiring immediate attention are being seen in the emergency room, Canning said.

The Prince George's Staff Nurse Chapter of the Maryland Nurses Association, with a membership of about 70 percent of the registered nurses on the staff, has asked for an agency shop where all registered nurses would be required to pay dues whether or not they belong to the union. The union has also asked for a third-party committee to study the role of the nurse and how much nurses should be paid. The corporation rejected both proposals.

The other point in the contract dispute, for which no new talks are scheduled, is wages. The corporation offered the nurses an immediate 35-cent-an-hour pay increase and another 35-cent increase next summer, but the union said the second raise was not sufficient.

Salary, Kaplan said yesterday, is a sign of how much society thinks a person is worth. "Nurses need clout," she said, pointing to her sign bearing the message: "The issue is professionalism in nursing." For years, she said, "nurses have allowed themselves to be pushed around."

She said she is trying hard not to think about being fired or about her dwindling bank checking account. But in another week, she will have to look for a temporary job, she said.

"I have sons who wear leather Nikes that cost $40," she said dryly.