Section 2. Except as hereinafter provided in this chapter, the provisions of chapters one hundred and seventy-five, one hundred and seventy-six A, one hundred and seventy-six B, one hundred and seventy-six C, one hundred and seventy-six E, and one hundred and seventy-six F, shall not apply to a health maintenance organization, provided, however, that in the case of any company doing business in the commonwealth and otherwise subject to the provisions of said chapters, this section shall apply only with respect to its health maintenance organization activities.