142 - 2823 days
||Rat Rattus norvegicus
||Teerds KJ, De Rooij DG, Rommerts FF, van der Tweel I, Wensing CJ. Turnover time of Leydig cells and other interstitial cells in testes of adult rats. Arch Androl. 1989 23(2):105-11 abstract, p.107 2nd paragraph & p.109 2nd paragraphPubMed ID2589905
||P.107 2nd paragraph: "As a result of repeated injections of [3H]thymidine, the percentage of labeled Leydig cells,
which was significantly different from zero (p < 0.01), increased gradually from 2 days to 8 days of treatment. After 8 days of [3H]thymidine treatment, the percentage of labeled Leydig cells had increased to 1.4% (Table 1). By using the linear regression analysis with subsequent
arcsin transformation of the percentage of labeled Leydig cells, the turnover time for this cell type could be calculated while the hypotheses of linearity and regression were not rejected. By extrapolation, an estimate could be given of the number of days required for labeling 100% of the Leydig cells: it would take 266 days (95% confidence interval, 142 to 2823 days) before all Leydig cells had become labeled."
||Abstract: "Taking into account the 95% confidence interval, the turnover time of Leydig cells ranged from 142 to 2823 days." P.109 2nd paragraph: "On the basis of the percentages of labeled
Leydig cells, the turnover time of the Leydig cells was estimated to be between 142 days and the maximum life span of the rat."