Behavioural responses and characterization of preputial gland extract of black rat, Rattus rattus

The present study was carried out to determine the chemistry of the preputial gland (PG) of mature male black rats and its role in sexual and social communication. 50% PG extracts from male rats of different age groups were prepared using n-hexane and dichloromethane and tested against black rats of different age groups and sexes. Results revealed that mature females were highly attracted towards and mature males were highly repelled from preputial gland extract of mature male rats for five and two days, respectively. Comparison of gas chromatography linked mass spectrometry analysis of fresh and eight days old PG extract revealed that 13 pheromonal compounds (.+/-.)-.alpha.-tocopherol acetate; acetophenone; undecane; dodecane; tridecane; tetradecane; heneicosane; docosane; squalene; cholesterol; octadecanal; palmitic acid; stigmastan-3,5-diene) were exclusively present in fresh extract but absent in eight days old preputial gland extract. These 13 compounds are already reported to have role in sexual and social communication in other mammals, insects and reptiles. They might be used by mature male rats for sexual and social communication. In the future, these identified compounds can be used in fixed proportions individually and in various combinations after testing their efficacy to develop a stable lure to increase the trappability and acceptability of antifertility agents and rodenticide-based baits for the management of black rats.