Gender differences in the hepatic transport of organic anions is well established. Although uptake of many organic anions is greater in females, sodium-dependent taurocholate uptake is greater in hepatocytes from male rats. We examined the hypothesis that endogenous estrogens alter the number of sinusoidal bile acid transporters and/or decrease membrane lipid fluidity. The initial sodium-dependent uptake of [3H]taurocholate was 75% greater in hepatocytes from males than from either intact or oophorectomized females rats. Taurocholate maximal uptake was increased twofold ( P < 0.03) without a significant change in the Michaelis-Menten constant. Sinusoidal membrane fractions were isolated from male and female rat livers with equal specific activities and enrichments of Na+-K+-ATPase. Males had a significant ( P < 0.05) increase in cholesterol esters and phosphatidylethanolamine-to-phosphatidylcholine ratio. Fluorescence polarization indicated decreased lipid fluidity in females. In females, expression of the sodium-dependent taurocholate peptide (Ntcp) and mRNA were selectively decreased to 46 ± 9 and 54 ± 4% ( P < 0.01), respectively, and the organic anion transporter peptide (Oatp) and Na+-K+-ATPase α-subunit were not significantly different. Nuclear run-on analysis indicated a 47% ( P < 0.05) decrease in Ntcp transcription, without a significant change in Oatp. In conclusion, these studies demonstrated that decreased sodium-dependent bile salt uptake in female hepatocytes was due to decreased membrane lipid fluidity and a selective decrease in Ntcp.

Terrestrial arthropod fauna have been suggested as a key indicator of ecological integrity in forest systems. Because phenotypic identification is expert-limited, a shift towards DNA metabarcoding could improve scalability and democratize the use of forest floor arthropods for biomonitoring applications. The objective of this study was to establish the level of field sampling and DNA extraction replication needed for arthropod biodiversity assessments from soil. Processing 15 individually collected soil samples recovered significantly higher median richness (488–614 sequence variants) than pooling the same number of samples (165–191 sequence variants) prior to DNA extraction, and we found no significant richness differences when using 1 or 3 pooled DNA extractions. Beta diversity was robust to changes in methodological regimes. Though our ability to identify taxa to species rank was limited, we were able to use arthropod COI metabarcodes from forest soil to assess richness, distinguish among sites, and recover site indicators based on unnamed exact sequence variants. Our results highlight the need to continue DNA barcoding local taxa during COI metabarcoding studies to help build reference databases. All together, these sampling considerations support the use of soil arthropod COI metabarcoding as a scalable method for biomonitoring.

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The oestrogen agonist and antagonist activity of a single dose of en-clomiphene (0.5--50 mg/kg) was studied in peripheral and brain tissue in the 3 week ovariectomized rat. 17 beta-Oestradiol benzoate (100 microgram/kg) or vehicle was injected 24 h after en-clomiphene administration and data collected at 72 h. En-clomiphene produced a dose-related (agonist) fall in body weight and food intake. Agonist action was not observed upon sexual receptivity and prolactin secretion; oestrogen antagonism of these parameters was only seen at the higher doses. The effects of en-clomiphene upon serum LH and FSH were complex, both agonist and antagonist activity being demonstrated in the absence and presence of oestrogen. En-clomiphene was uterotrophic at all doses tested; however, oestrogen antagonism was only seen at the higher doses. Inhibition of the accumulation of uterine luminal fluid at the higher doses of en-clomiphene was a sensitive index of oestrogen antagonism. The results are discussed in relation to previous studies of the effects of en-clomiphene on oestrogen receptors. With the exception of the antagonism of oestrogen-induced sexual receptivity no correlation could be made between biological activity and the status of oestrogen receptors in tissue.