title: Influence of the menstrual cycle on the absorption and elimination of D-xylose.
abstract: Thirteen healthy female volunteers with regular menstrual cycles (28 +/- 2 days) received 25 gm oral and 5 gm intravenous doses of D-xylose on 2 successive days during the follicular, ovulatory, and luteal phases of two consecutive menstrual cycles. The ovulation time was characterized by luteinizing hormone levels, body basal temperatures, and progesterone and estradiol serum levels. D-Xylose was assayed in plasma and urine with a phloroglucinol-based colorimetric method. The findings of this study indicated that menstrual cycle did not significantly affect D-xylose absorption. After oral administration, the total clearance was significantly increased in cycle 2 during the luteal phase (p = 0.004). After intravenous administration in both cycles, D-xylose total clearance was also significantly faster during the luteal phase (p = 0.038 and p = 0.041, respectively). After oral administration, the renal clearance tended to be higher during the luteal phase in both cycles studied. After intravenous administration, this parameter was increased during the luteal phase by 24% and 25% in cycle 1 and by 8% and 12% in cycle 2. These findings are consistent with those of others showing an increase in glomerular filtration rate (GFR) during the luteal phase of the menstrual cycle. The findings of this study seem to be explained by the hormonal changes occurring during the menstrual cycle. Further investigations are warranted with use of specific probes of renal processes (GFR, renal reabsorption and tubular secretion) to confirm our findings and to elucidate the underlying mechanisms.
authors.affiliation: Laboratoire de Pharmacocinétique clinique, Ecole de Pharmacie, Université Laval, Québec, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Fiset
authors.forename: M
authors.initials: M
authors.lastname: LeBel
mesh_terms: D000042:Absorption; D000284:Administration, Oral; D000328:Adult; D005260:Female; D005498:Follicular Phase; D006801:Humans; D007275:Injections, Intravenous; D008183:Luteal Phase; D008597:Menstrual Cycle; D014994:Xylose / Q000008:administration & dosage / Q000493:pharmacokinetics*
chemical_list: D014994:Xylose