“…The number of cells undertaking the differentiating process, as well as the incorporation rate of lipogenic precursors into trigylceridefatty acids, were enhanced by addition of triiodothyronine in cell cultures of ob 17 lines (Gharbi-Chihi, Grimaldi, Torresani and Ailhaud 1981;Grimaldi, Djian, Forest, Poll, Negrel and Ailhaud 1983) and in primary cultures (unpublished results). Moreover, in vivo, de novo lipogenesis could not be correlated to fat cell size {Holm, Jacobson, (Bjorntorp and Smith 1975), but has been reported to depend on age (Gandemer, Pascal and Durand 1982) and on adipose tissue localization (Fried, Lavau and Pi-Sunyer 1981). Since, in culture, new fat cell recruitment was partly related to de novo lipogenesis stimulation, it is therefore tempting to postulate a similar relationship in vivo.…”