<PAGE>   1
                                                                   EXHIBIT 10.75

                               AMENDMENT NO. 2 TO
                              AMENDED AND RESTATED
                  REVOLVING CREDIT AND REIMBURSEMENT AGREEMENT

         THIS AMENDMENT AGREEMENT is made and entered into this 18th day of
September, 1997, by and among CAPSTONE CAPITAL CORPORATION, a Maryland
corporation (herein called the "Borrower"), NATIONSBANK, NATIONAL ASSOCIATION
(successor by merger of NationsBank, N.A. (South) (the "Agent"), as Agent for
the lenders (the "Lenders") party to the Amended and Restated Revolving Credit
and Reimbursement Agreement dated June 24, 1996 among such Lenders, Borrower and
the Agent, as amended (the "Agreement") and the Lenders (the "Increasing
Lenders") party to this Amendment Agreement.

                              W I T N E S S E T H:

         WHEREAS, the Borrower, the Agent and the Lenders have entered into the
Agreement pursuant to which the Lenders have agreed to make revolving loans to
the Borrower in the principal amount of $170,000,000 as evidenced by the Notes
(as defined in the Agreement); and

         WHEREAS, the Lender has agreed to provide to Borrower Loans of up to
$10,000,000 thereby increasing the Total Revolving Credit Commitment to
$180,000,000 and the parties hereto desire to amend the Agreement in the manner
herein set forth effective as of the date hereof;

         NOW, THEREFORE, the Borrower, the Agent and the Lender do hereby agree
as follows:

         1. Definitions. The term "Agreement" as used herein and in the Loan
Documents (as defined in the Agreement) shall mean the Agreement as hereby
amended and modified. Unless the context otherwise requires, all terms used
herein without definition shall have the definition provided therefor in the
Agreement.

         2. Amendments. Subject to the conditions hereof, the Agreement is
hereby amended, effective as of the date hereof, by deleting Exhibit A and
inserting in lieu thereof Exhibit A attached hereto, and the Lender agrees by
the execution of this Amendment Agreement that it shall be a party to the
Agreement and shall provide the Borrower its Revolving Credit Commitment.

         3. Representations and Warranties. The Borrower hereby certifies that:

            (a) The representations and warranties made by Borrower in Article
         VI thereof are true on and as of the date hereof except that the
         financial statements referred to in Section 6.01(f) shall be those most
         recently furnished to each Lender pursuant to Section 7.01(a) and (b);


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           (b) There has been no material change in the condition, financial or
         otherwise, of the Borrower and its Subsidiaries since the date of the
         most recent financial reports of the Borrower received by each Lender
         under Section 7.01 thereof, other than changes in the ordinary course
         of business, none of which has been a material adverse change;

           (c) The business and properties of the Borrower and its Subsidiaries
         are not, and since the date of the most recent financial report of the
         Borrower and its Subsidiaries received by each Lender under Section
         7.01 thereof have not been, adversely affected in any substantial way
         as the result of any fire, explosion, earthquake, accident, strike,
         lockout, combination of workers, flood, embargo, riot, activities of
         armed forces, war or acts of God or the public enemy, or cancellation
         or loss of any major contracts; and

           (d) No event has occurred and no condition exists which, upon the
         consummation of the transaction contemplated hereby, constituted a
         Default or an Event of Default on the part of the Borrower under the
         Agreement or the Notes either immediately or with the lapse of time or
         the giving of notice, or both.

         4. Conditions. As a condition to the effectiveness of this Amendment
Agreement, the Borrower shall deliver, or cause to be delivered to the Agent,
the following:

           (a) Five (5) executed counterparts of this Amendment Agreement; and

           (b) Fully-executed Notes payable to the Lenders in the amount of
         Lender's Revolving Credit Commitment.

         5. Other Documents. All instruments and documents incident to the
consummation of the transactions contemplated hereby shall be satisfactory in
form and substance to the Agent and its counsel; the Agent shall have received
copies of all additional agreements, instruments and documents which it may
reasonably request in connection therewith, including evidence of the authority
of Borrower to enter into the transactions contemplated by this Amendment
Agreement, in each case such documents, when appropriate, to be certified by
appropriate corporate or governmental authorities; and all proceedings of the
Borrowers relating to the matters provided for herein shall be satisfactory to
the Agent and its counsel.

         6. Entire Agreement. This Amendment Agreement sets forth the entire
understanding and agreement of the parties hereto in relation to the subject
matter hereof and supersedes any prior negotiations and agreements among the
parties relative to such subject matter. No promise, conditions, representation
or warranty, express or implied, not herein set forth shall bind any party
hereto, and no one of them has relied on any such promise, condition,
representation or warranty. Each of the parties hereto acknowledges that, except
as in this Amendment Agreement or otherwise expressly stated, no
representations, warranties or commitments, express or implied, have been made
by any other party to the other. None of the terms or conditions of this
Amendment Agreement may be changed, modified, waived or canceled orally or
otherwise, except by writing, signed by all the parties hereto, specifying such
change, modification, waiver or cancellation of such terms or conditions, or of
any proceeding or succeeding breach thereof.




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         7. Full Force and Effect of Agreement. Except as hereby specifically
amended, modified or supplemented, the Agreement and all of the other Loan
Documents are hereby confirmed and ratified in all respects and shall remain in
full force and effect according to their respective terms.

         IN WITNESS WHEREOF, the parties hereto have caused this Amendment
agreement to be duly executed by their duly authorized officers, all as of the
day and year first above written.

                                         CAPSTONE CAPITAL CORPORATION
WITNESS:

/s/ Krista M. Young                      By: /s/ Andrew L. Kizer
----------------------------------           --------------------------------


/s/ Suzanne H. Duffy                     Name:  Andrew L. Kizer
----------------------------------       Title: Vice President




<PAGE>   4



                                          NATIONSBANK, NATIONAL ASSOCIATION
                                          as Agent


                                          By: /s/ Scott S. Ward
                                              --------------------------------
                                          Name:    Scott S. Ward
                                          Title:   Senior Vice President





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                                          CREDITANSTALT CORPORATE FINANCE, INC.


                                          By: /s/ Robert M. Biringer
                                              --------------------------------
                                          Name:   Robert M. Biringer
                                          Title:  Executive Vice President


                                          By: /s/ W. Craig Stamm
                                              --------------------------------
                                          Name:   W. Craig Stamm
                                          Title:  Vice President



<PAGE>   6




                                          THE SUMITOMO BANK, LIMITED


                                          By: /s/ Lauren P. Carrigan
                                              --------------------------------
                                          Name:    Lauren P. Carrigan
                                          Title:   Assistant Vice President

                                          By: /s/ Diane M. Rhoades
                                              --------------------------------
                                          Name:    Diane M. Rhoades
                                          Title:   Executive Officer



<PAGE>   7



                                    EXHIBIT A


                        Applicable Commitment Percentages


<TABLE>
<CAPTION>
                                                                                            Applicable
                                                                                            ----------
                                                        Revolving Credit                    Commitment
                                                        ----------------                    ----------
Lender                                                     Commitment                        Percentage
------                                                  ----------------                   -------------
<S>                                                       <C>                              <C>
NationsBank, National Association                         $ 45,000,000                     25.000000000%
AmSouth Bank of Alabama                                   $ 25,000,000                     13.888888889%
Credit Lyonnais New York Branch                           $ 30,000,000                     16.666666667%
National City Bank of Kentucky                            $ 15,000,000                      8.333333333%
Creditanstalt Corporate Finance, Inc.                     $ 30,000,000                     16.666666667%
The Bank of Nova Scotia                                   $ 10,000,000                      5.555555556%
First Commercial Bank                                     $ 10,000,000                      5.555555556%
The Sumitomo Bank, Limited                                $ 15,000,000                      8.333333333%
                                                          ------------                     ------------
         Total                                            $180,000,000                              100%
</TABLE>