(CNN) -- Sen. Edward Kennedy was hospitalized in Boston, Massachusetts, after suffering an apparent seizure Saturday morning, his family said.
Sen. Ted Kennedy, shown in May 2007, was rushed to a hospital Saturday morning.
"Preliminary tests have determined that he has not suffered a stroke and is not in any immediate danger. He's resting comfortably, and watching the Red Sox game with his family," said Dr. Larry Ronan, a physician at Massachusetts General Hospital.
"Over the next couple of days, Sen. Kennedy will undergo further evaluation to determine the cause of the seizure, and a course of treatment will be determined at that time," said Ronan, who is Kennedy's primary care physician.
Senate Majority Leader Harry Reid said Saturday he spoke to the wife of the Massachusetts Democrat, Victoria Reggie Kennedy, and she told him her husband is going to be fine.
"Everyone knows he is a strong fighter," Reid said, speaking at the Nevada state Democratic Party convention.
Kennedy was transferred to Massachusetts General Hospital in Boston for evaluation after initial treatment at Cape Cod Hospital, an earlier statement from his office said.
The senator spent less than an hour in the Cape Cod facility, hospital spokesman David Reilly said.
Earlier, a Democratic source in Massachusetts said the 76-year-old senator had "symptoms of a stroke" at the Kennedy family compound in Hyannisport.
An official with the Hyannis Fire Department said it received a 911 call from the Kennedy compound at 8:19 a.m. and transported a male patient to the hospital, arriving at 8:50 a.m. Watch how paramedics' fast response time may have saved Kennedy's life »
The patient was subsequently transferred to the hospital's municipal airport, and a Boston Med Flight helicopter flew the man to Massachusetts General, Lt. Bill Rex said.
Family members reported that Kennedy was well enough later in the morning to call to say he would not be able to join them for lunch.
They said they were guardedly optimistic he would make a full recovery. Watch what lies ahead in Kennedy's recovery »
Kennedy had surgery in October to clear his carotid artery in hopes of preventing a stroke. Colleagues said he had recovered quickly and was working energetically recently. Watch
He suffers chronic back pain from injuries suffered in a plane crash in 1964.
Kennedy has represented Massachusetts in the Senate since 1962. He is one of only six senators in U.S. history to serve more than 40 years. He is known as a liberal champion of social issues such as health care, family leave and the minimum wage. Take a closer look at Kennedy's life »
He ran unsuccessfully for the Democratic presidential nomination in 1980. He has endorsed Illinois Sen. Barack Obama for the 2008 nomination.
Obama said that his "thoughts and prayers" are with Kennedy.
"We are going to try to find out as quickly as possible what is going on," Obama said, and added that he would call Kennedy's wife.
"He is one of my favorite people," Obama said.
The presumptive Republican presidential nominee, Sen. John McCain of Arizona, said in a statement he was "very sorry to hear that Sen. Kennedy has taken ill and, like millions of Americans, Cindy and I anxiously await word of his condition."
The two senators are close friends despite differing political ideologies. They co-sponsored a comprehensive immigration bill that has stalled in the Senate.
"He is a legendary lawmaker," McCain said.
Presidential candidate Sen. Hillary Clinton, D-New York, said: "My thoughts and prayers are with Ted Kennedy and his family today. We all wish him well and a quick recovery."
John Kerry, the junior senator from Massachusetts, was seen arriving at Massachusetts General Hospital on Saturday afternoon.
Kennedy is the youngest of nine children in the famous family of Joseph and Rose Kennedy. His oldest brother, Joe, died in World War II; two other brothers, President John F. Kennedy and Sen. Robert Kennedy, were assassinated in the 1960s.
CNN's John King, Josh Levs, Dana Bash, Ed Henry, Mike Roselli and Dan Lothian contributed to this report.
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