Urinary Progestogen and Estrogen Excretion During Pregnancy in Eulemur macaco flavifrons, E. rubriventer, and Hapalemur griseus occidentalis

Abstract

Via a non-invasive approach, we aimed to provide comparative data on the presence and relative abundance of progestogen and estrogen metabolites excreted into the urine of Eulemur rubriventer, E. macaco flavifrons and Hapalemur griseus occidentalis and to characterize the patterns of progestogen and estrogen excretion during pregnancy. We found that estrone is the major urinary estrogen in Eulemur macaco flavifrons and Hapalemur griseus occidentalis, while 16α-hydroxyestrone appeared to be the predominant estrogen in the urine of E. rubriventer. Estradiol-17s was either absent (Hapalemur) or present in very low amounts. HPLC of progestogens had high levels of immunoreactivity in an assay against 5α-pregnane-3α-ol-20-one (5-P-3OH) in each species, though the nature of the progestogens measured by the 5-P-3OH assay differed among species. During pregnancy, 5-P-3OH levels remained relatively low in Eulemur rubriventer, whereas in E. macaco flavifrons and Hapalemur griseus occidentalis, a sustained elevation in levels occurred from mid-pregnancy until the final weeks before parturition. Estrogen excretion differed depending on the sex of the fetus in each species, with only females carrying male infants showing clearly elevated estrogen levels during the last 6–8 weeks of gestation. In conclusion, we demonstrate both species similarities and differences in the metabolism and urinary excretion patterns of reproductive hormones throughout gestation in the Lemuridae. The data not only extend our knowledge on the reproductive physiology of lemurs but also show that more studies on other lemur taxa are needed to provide a broader basis for interspecific comparison.