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1 In the bovine ciliary muscle, stimulation of muscarinic receptors with carbachol (CCh) opens two types of non-selective cation channels (NSCCS and NSCCL) with widely different unitary conductances (100 fS and 35 pS). Here we examined the dependence of the activity of NSCCS on the agonist (CCh) concentration by whole-cell voltage clamp in freshly isolated bovine ciliary muscle cells. We also examined the sensitivity of CCh-evoked NSCCS currents to several muscarinic receptor antagonists. 2 The voltage clamp experiments were carried out using Ba2+ as the charge carrier, as this divalent cation is the most permeant for NSCCS of the alkali and alkaline earth metal ions hitherto examined, whereas it is relatively impermeant to NSCCL. For the dose–activation relationship obtained, the apparent dissociation constant K was estimated to be 0.5 ± 0.2 μm ( n = 31), a value of an order of magnitude smaller than the one reported for CCh-evoked NSCCL currents in our previous experiments. 3 In the dose-inhibition experiments we observed that the CCh-evoked NSCCS currents were inhibited by the muscarinic antagonists with the following potency sequence: atropine ≈ 4-DAMP >> pirenzepine > AF-DX116, indicating that the activation of NSCCS by CCh is mediated by an M3 muscarinic receptor. 4 We have previously shown by reverse transcriptase-polymerase chain reaction that the bovine ciliary muscle contains mRNAs for several transient receptor potential channel homologues (TRPC1, TRPC3, TRPC4 and TRPC6) which are attracting attention as molecular candidates for receptor-operated NSCCs. In the present experiments, we succeeded in visually identifying these TRPCs in the plasma membrane of cultured bovine ciliary muscle cells by immunofluorescence microscopy. [ABSTRACT FROM AUTHOR]

Tartary buckwheat protein product (TBP) was prepared from buckwheat flour by alkali extraction and isoelectric precipitation. The protein content of TBP was 45.8%, and its amino acid composition of TBP was similar to that of common buckwheat protein product (BWP). SDS-PAGE analysis showed that the protein profile of TBP was partially different from that of BWP. TBP contained more quercetin (1710 mg/100 g) than BWP (5.4 mg/100 g), while there was a small difference in the contents of rutin between them. In experiment 1, the consumption of BWP and TBP at 20% net protein level for 13 d caused 32% and 25% reductions in serum cholesterol of rats fed cholesterol, respectively, when compared to the consumption of casein ( P < 0.05). The reduction of serum cholesterol by BWP and TBP was associated with enhanced excretion of fecal neutral sterols. In experiment 2, the consumption of BWP and TBP for 27 d caused 62% and 43% reductions in the lithogenic index in mice fed cholesterol, respectively ( P < 0.05). The reduction in lithogenic index was associated with enhanced excretion of fecal bile acids. Taken together, these results suggest a potential source of TBP as a functional food ingredient as well as BWP. [ABSTRACT FROM AUTHOR]