New issues in U.S. corporate bond markets topped $38 billion last week, with four borrowers taking on more than $3 billion each to account for more than a third of the total. Here’s a look at who’s doing the borrowing and what they're doing with the money.

Bank of America (NYSE:BAC) floated $4 billion in new notes in four tranches with maturities ranging from three to 30 years. As is typical for financials, the use of proceeds statement didn’t offer anything beyond "general corporate purposes."

Comcast's (NASDAQ:CMCSA) NBC Universal broadcast $4 billion spread over three-, five-, and six-year notes. The money is headed to General Electric as part of the payment for the sale of NBC Universal.

Sticking with the buyout theme, Heinz (UNKNOWN:HNZ.DL) squirted out $3.1 billion in 7.5-year junk bonds to finance its buyout by Berkshire Hathaway and 3G Capital Partners. The Wall Street Journal reports that the 4.25% coupon is a record low for debt tied to a leveraged buyout.

Privately held Intelsat was the other top-four borrower, launching $3.5 billion staged over five-, eight-, and 10-year paper.

Medtronic (NYSE:MDT) sold $2.75 billion of new notes in doses of five-, 10-, and 30-year maturities. The money will be used to repay commercial paper and some notes maturing over the next three years.

St. Jude Medical issued $1.6 billion split between 10- and 30-year notes. The money will be used to redeem two bond issues and for general corporate purposes. One of the issues being redeemed doesn't mature until 2019, and St. Jude isn't saving much on the coupon rate. I assume the company simply wants to lock in today's low rates.

CenturyLink (NYSE:CTL) made the billion-dollar borrowers club with a $1 billion, seven-year, high-yield issue. The money will be used to repay part of a revolving credit facility, repay some senior notes maturing next month, and for general corporate purposes.

Stryker hip-checked into the billion dollar club with $1 billion split between five- and 30-year notes. The money will be used for "working capital and other general corporate purposes, including acquisitions, stock repurchases and other business opportunities."

Buyout funding and refinancing were popular reasons for borrowing last week. Whether high-yield or junk, borrowing made up nearly $14 billion of the total, including the 4.25% Heinz issue, which doesn’t seem like a high-yielder.