Improvement in Chick Comb Response to Androsterone Obtained with Alcohol as Vehicle. ∗

Abstract

In our studies of the bioassay method for androgens, utilizing the comb of the baby chick, it has appeared that further improvement in the method might be attained by utilizing some vehicle for the androgens other than sesame oil. We have been aware of the fact that an oily vehicle entails certain disadvantages: (1) It has a tendency to spread over the head feathers of the chick and thus cause a loss of variable amounts of the hormone by diversion from the comb. (2) As a solvent, oil is unsatisfactory particularly for the gummy residues frequently obtained in extracting androgens from urine. (3) The oil itself is not absorbed, as has been shown histo-logically by Soloway, Hansen and McCahey, 1 but the hormone is absorbed selectively by diffusion out of the vehicle instead of along with it. (4) The high viscosity of an oily vehicle is a distinct source of error in the preparation of quantitative solutions of the androgens. Other liquids which have been employed in place of sesame oil are tri-caproin (Hall and Dryden 2 ), 60% alcohol for estrogens (Ito, Hajazu and Kon 3 ), and 96% alcohol for testosterone (Zondek and Sulman 4 ) . The latter also mention the possibility of using benzol, ether, benzene and acetone but report no comparative studies with these solvents. Since 95% alcohol tends to overcome the undesirable features of sesame oil enumerated above, we have compared the two vehicles with respect to the comb growth response elicited by identical doses of androsterone. The procedure was similar to that described in the preceding paper (Klempner, Hollander and Frank 5 ), wherein we compared the response elicited by the same dose of androsterone in paired experiments in which the only variable was the volume of sesame oil employed.