3H-L-leucine transport by the promiscuous crustacean dipeptide-like cotransporter.

The crustacean intestine and hepatopancreas display a variety of solute transport mechanisms for transmembrane transfer of dietary contents from lumen to epithelial cytosol. An in vitro intestinal perfusion apparatus was used to characterize mucosal to serosoal (MS) and serosal to mucosal (SM) Zn(2+) -dependent (3)H-L-leucine transport by the intestine of the American lobster, Homarus americanus. Transmural 20 µM MS (3)H-L-leucine fluxes across lobster intestine were a hyperbolic function of luminal zinc concentration (1-50 µM) following Michaelis-Menten kinetics (K(m) = 2.67 ± 0.74 µM; J(max) = 19.56 ± 2.22 pmol/cm(2) ×min). Transmural 20 µM SM (3)H-L-leucine fluxes were not affected by serosal zinc, resulting in a highly significant stimulation of net amino acid transfer to the blood by luminal metal. MS fluxes of 20 µM (3)H-L-leucine were also hyperbolic functions of luminal [Cu(2+)], [Mn(2+)], [Na(+)], and [H(+)]. MS flux of (3)H-L-leucine was a sigmoidal function of luminal [L-leucine] and was stimulated by the addition of 20 µM luminal zinc at both pH 7.0 and 5.5. A greater enhanced amino acid transport occurred at the lower pH 5.5. MS flux of 20 µM (3)H-L-leucine in the presence of 20 µM zinc was significantly inhibited by addition of 100 µM luminal glycylsarcosine, and MS flux of 20 µM (3)H-glycylsarcosine was inhibited by 100 µM L-leucine in the presence of 20 µM zinc. Results suggest that (3)H-L-leucine and metals form a complex (e.g., Leu-Zn-Leu] that may functionally mimic dipeptides and use a dipeptide-like transporter during MS fluxes as suggested for fish and mammals.

Prevalence of polycystic ovary syndrome in women seeking treatment from community electrologists. Alabama Professional Electrology Association Study Group.

OBJECTIVE: To determine the prevalence of the polycystic ovary syndrome (PCOS) among women seeking electrology, clients presenting to nine electrology centers completed a questionnaire. STUDY DESIGN: Women with potential risk factors were referred to the University of Alabama at Birmingham. They underwent a detailed history and physical examination, including hirsutism scoring by a modified Ferriman-Gallwey (F-G) method. Serum was assayed for total testosterone, sex hormone binding globulin and dehydroepiandrosterone sulfate. RESULTS: Three hundred fifteen (40%) of 779 patients had potential risk factors for hyperandrogenism and were referred. Eighty-two (26%) completed their evaluation. Six were excluded secondary to prepubertal or menopausal status. Of the remaining 76 patients, 20% had F-G scores of 7 or 8, 13% had scores of 9 or 10, and 21% had scores > 10. Forty-nine (64%) patients reported irregular menstrual cycles. Sixty-four patients were not receiving hormonal therapy: 25 reported regular menstrual cycles, and 39 reported irregular cycles. Seventeen (68%) of the 25 had at least one abnormal androgen value, while 33 (85%) of the 39 women had at least one abnormal value (nonsignificant difference). Overall, PCOS was evident in 39 of the 76 women, or 12% of the 315 patients who were referred for further evaluation. CONCLUSION: Thirty-nine of the 315 referred patients (12%) fulfilled the diagnostic criteria for PCOS. However, they were not receiving medical care for this condition. In addition, this percentage is a conservative estimate in that 74% of the referred patients did not pursue a medical evaluation. Therefore, efforts to educate both electrologists and their clients of the possibility of underlying endocrine disorders and subsequent metabolic morbidity should be undertaken.