Search PubMed⌕ Search

Biomedical subjects

Z L Qin

Publications and source records attributed to Z L Qin.

9 recordsLinked to original sources
PubMed2001

[Trace elements and extracellular matrix].

OBJECTIVE: To investigate the effects of trace elements on the metabolism of extracellular matrix and explore the physiological and pathological mechanism of trauma. METHODS: Based on the experimental and clinical data, it was studied that the action of trace elements in the metabolism of extracellular matrix in trauma repairing. RESULTS: During wound healing, the trace elements were the components of many kinds of enzymes, carriers and proteins. They took part in the synthesis of hormones and vitamins as well as the transmission of information system. They activated many different kinds of enzymes and regulate the levels of free radicals. The trace elements had the complicated effects on the synthesis, decompose, deposition and reconstruction of collagen and other extracellular matrix. CONCLUSION: The trace elements play an important role in regulating the metabolism of extracellular matrix.

Collagen↗
PubMed1999

Vascular angiotensin II receptor and calcium signaling in toadfish.

The renin-angiotensin system evolved during the early evolution of vertebrates and regulates blood pressure/blood volume homeostasis in nonmammalian and mammalian vertebrates. Properties of vascular angiotensin (ANG) receptors and signal pathways in primitive animals are, however, not well understood. We aimed to determine whether vascular ANG II receptors in the toadfish, Opsanus tau, an aglomerular teleost, pharmacologically resemble either the ANG subtype 1 receptor (AT1) or the subtype 2 receptor (AT2) by examining (i) the effects of selective ANG receptor antagonists on ANG II-induced vasopressor action and binding and (ii) ANG II's effect on cytosolic Ca2+ signaling. [Asn1, Val5]ANG II (native teleost ANG II) dose-dependently increased the mean arterial pressure of conscious toadfish. ANG II-induced pressor responses (100-500 ng/kg) were inhibited substantially (79-83%) by [Sar1, Ile8]ANG II (5 microg x kg-1 + 5 microg x kg-1 x min-1) and moderately (34-53%) by losartan (AT1 antagonist, 10 mg/kg + 20 mg x kg-1 x h-1) and by PD 123319 (AT2 antagonist, 10 mg/kg + 20 mg x kg-1 x h-1) (36-60%). Likewise, the [Asp1, Val5, His9]ANG I-induced pressor effect was completely eliminated by an ANG I-converting enzyme inhibitor, SQ 14,225. Specific 125I-ANG II binding to vascular smooth muscle (VSM) membrane fractions was displaced completely by [Asn1, Val5]ANG II and [Sar1, Ile8]ANG II. Losartan, but not PD 123319, partly displaced ANG II binding at 10(-10)-10(-6) M. Furthermore, ANG II (10(-7) or 10(-8) M) caused a rapid, transient increase in the cytosolic Ca2+ signal (fluorescence ratio (FR) of 340/380 nm) of isolated VSM tissues measured by fura-2 and a dual wavelength fluorospectrometer, whereas extracellular K+ induced sustained, dose-dependent (P < 0.01) increases in FR. The results indicate that toadfish VSM tissues possess a rather nonselective ANG receptor; partial inhibition of ANG II binding by losartan and stimulation of cytosolic Ca2+ signaling by ANG II suggest that the receptor has some resemblance to AT1 homologous receptors.

1-Sarcosine-8-Isoleucine Angiotensin II↗
PubMed1998

Ca2+ signaling in fowl aortic smooth muscle increases during maturation but is impaired in neointimal plaques.

Many bird species show the spontaneous development of high arterial pressure and vascular lesions in the aorta and other large arteries. In chickens, arterial pressure tends to increase with age/maturation (particularly in males), and subendothelial hyperplasia (neointima) in the abdominal aorta is often seen prior to sexual maturation. The mechanisms involved, however, are not known. Our aim, therefore, was to determine (1) whether cytosolic Ca2+ signaling (CCS) responses to vasoactive substances in fowl aortic smooth muscle differ among chickens at different maturation stages and (2) whether CCS responses to Ca2+ channel agonists in neointimal plaques differ from those in normal aortic smooth muscle. K+ increased CCS in a dose-dependent manner in isolated and superfused abdominal aortic smooth muscle tissue from chicks (5-9 weeks old), pullets (11-18 weeks old) and adult hens (20 weeks and older); CCS responses increased as chickens matured. The addition of Bay K 8644 (10(-6)mol l-1) to Ringer's solution containing 50 mmol l-1 K+ further increased CCS, and this response was reduced to half by nifedipine (10(-6)mol l-1). Norepinephrine did not alter CCS in chicks, whereas marked dose-dependent increases in CCS were noted in pullets. In contrast to the CCS responses to K+, the norepinephrine-induced CCS responses became smaller in adult hens. Isolated neointimal plaques showed only slight increases in CCS in response to 50 mmol l-1 K+ plus Bay K 8644, whereas clear responses were noted in aortic smooth muscle tissue underlying the plaques. These results suggest (1) that CCS responses to Ca2+ channel agonists increased with sexual maturation in fowl, but (2) that CCS responses to norepinephrine were low in mature hens and to K+ plus Bay K 8644 were low in spontaneously developed neointima, suggesting that phenotypic modulation of Ca2+ channel/norepinephrine receptors may have occurred during maturation/aging and in neointima.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1991

[RP-HPLC determination of 1-(p-methylphenyl-2-(2-piperidinoacetyl- 1,2,3,4-tetrahydroisoquinoline hydrochloride in rabbit plasma and its pharmacokinetic parameters].

A reversed phase high performance liquid chromatographic method (RP-HPLC) was developed for the determination of rabbit plasma levels of 1-(p-methylphenyl-2-(2-piperidinoacetyl)-1, 2, 3, 4-tetrahydroisoquinoline hydrochloride (70026), a new antiarrhythmic agent with promising prospects. Its pharmacokinetic parameters were obtained from the rabbit plasma level-time curve measured. 70026 plasma sample was determined by extracting with ether and 0.2 mol/L sulfuric acid, chromatographing on LiChrosorb RP-C18 column, and detecting at 230 nm. The mobile phase selected was methanol-water-triethylamine-phosphoric acid (63:37:1:0.8 v/v). The average recovery of the entire procedure from plasma was 99.94 +/- 3.10 (SD) %; the average CV of within-day and between-day were 4.12% and 3.95% respectively; the minimum detection limit was 3 ng; 70026 plasma concentration ranging from 25-2000 ng/ml yielded a good linear relationship with the peak area ratios, Y = 0. 002865X-0.01346, r = 0. 9999. No endogeneous interference was found in chromatograms of plasma sample. The purity of chromatographic peak of 70026 was identified and proved by mass spectrometry. In urine sample, the hydrolysate of 70026 was found as the original and bound forms. The rabbit plasma level of 70026 after intravenous administration versus time curve was found to be in correspondence with two-compartment model, T1/2 = 4.80 + 1.522 (h).

Animals↗