A Role of Steroidal Substances in the Male Abdominal Gland of the Newt, Cynops pyrrhogaster

Abstract

Sodefrin, a peptide pheromone, has been considered to be a major female-attr acting substance released from the abdominal gland of the male newt, Cynops pyrrhogaster. Recently, we found that a considerable amount of steroidal substances such as pregnenolone, progesterone, androstenedione and estradiol exsists in the abdominal gland of the male newt. Moreover it was confirmed that pregnenolone and androstenedione are released into the duct of the abdominal gland, As a step to elucidate the role of these substances, they were tested for their female-attracting activity employing the method developed by Toyoda et al.(1994). As a result, these two steroidal substances to be contained in 0.01 part of the abdominal gland was revealed to have a female-attracting activity. It was also revealed that a mixture of these steroids and sodefrin exerts more potent attracting activity than the steroids or sodefrin alone, These results strongly suggest that both steroids and the peptide pheromone are released from the gland and act together to attract sexually developed females during courtship.Toyoda et al. (1994). Physiology and Behavior, 55, 569-576. [J Physiol Sci. 2007;57 Suppl:S174]