An insurer may invest in loans which are secured by pledge of securities eligible for investment under this article or by the pledge or assignment of life insurance policies issued by other insurers authorized to transact insurance in this state. On the date made, no loan shall exceed in amount 75 percent of the market value of the collateral pledged. The amount so loaned shall be included in the maximum percentage of funds permitted under this article to be invested in the kinds of securities or evidences of debt pledged.