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12.
High blood alcohol levels in women. The role of decreased gastric alcohol dehydrogenase activity and first-pass metabolism 总被引:35,自引:0,他引:35
M Frezza C di Padova G Pozzato M Terpin E Baraona C S Lieber 《The New England journal of medicine》1990,322(2):95-99
After consuming comparable amounts of ethanol, women have higher blood ethanol concentrations than men, even with allowance for differences in size, and are more susceptible to alcoholic liver disease. Recently, we documented significant "first-pass metabolism" of ethanol due to its oxidation by gastric tissue. We report a study of the possible contribution of this metabolism to the sex-related difference in blood alcohol concentrations in 20 men and 23 women. Six in each group were alcoholics. The first-pass metabolism was determined on the basis of the difference in areas under the curves of blood alcohol concentrations after intravenous and oral administration of ethanol (0.3 g per kilogram of body weight). Alcohol dehydrogenase activity was also measured in endoscopic gastric biopsies. In nonalcoholic subjects, the first-pass metabolism and gastric alcohol dehydrogenase activity of the women were 23 and 59 percent, respectively, of those in the men, and there was a significant correlation (rs = 0.659) between first-pass metabolism and gastric mucosal alcohol dehydrogenase activity. In the alcoholic men, the first-pass metabolism and gastric alcohol dehydrogenase activity were about half those in the nonalcoholic men; in the alcoholic women, the gastric mucosal alcohol dehydrogenase activity was even lower than in the alcoholic men, and first-pass metabolism was virtually abolished. We conclude that the increased bioavailability of ethanol resulting from decreased gastric oxidation of ethanol may contribute to the enhanced vulnerability of women to acute and chronic complications of alcoholism. 相似文献
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Sanjana VM; Johnston PA; Robertson CR; Jamison RL 《The American journal of physiology》1976,231(2):313-318
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Zelinski-Wooten MB; Slayden OD; Chwalisz K; Hess DL; Brenner RM; Stouffer RL 《Human reproduction (Oxford, England)》1998,13(2):259-267
Large doses of antiprogestin typically disrupt menstrual cyclicity. A
chronic low-dose regimen of the potent new antiprogestin ZK 137 316, which
permits continued menstrual cyclicity but alters gonadal- reproductive
tract activity, was established. Rhesus monkeys received vehicle (n = 6) or
0.01 (n = 8), 0.03 (n = 8) or 0.1 (n = 5) mg ZK 137 316/kg body weight
daily for five menstrual cycles (C-1 to C-5). Oestradiol, progesterone and
gonadotrophin profiles were normal during cycles involving vehicle and 0.01
and 0.03 mg ZK 137 316/kg body weight. In the 0.1 mg/kg group, mid-cycle
oestradiol and gonadotrophin surges, and subsequent progesterone
production, were absent in C-3 and C-5. Ovarian cyclicity was accompanied
by timely menstruation in the vehicle and 0.01 mg/kg groups. By C-3, half
the animals in the 0.03 mg/kg group and all animals in the 0.1 mg/kg group
were amenorrhoeic. A corpus luteum was noted during the mid-luteal phase of
C-5 in the vehicle, 0.01 mg/kg and 0.03 mg/kg groups. Large antral and
cystic follicles were evident in the 0.1 mg/kg group. Thus, a daily
treatment with 0.01 mg/kg ZK 136317 permitted normal menstrual cyclicity in
macaques. While the daily administration of 0.03 mg/kg ZK 136 317 allowed
ovarian cyclicity, menstruation was disrupted in some animals. Increasing
the dose to 0.1 mg/kg antagonized pituitary function and resulted in
anovulation and amenorrhoea. A chronic low-dose regimen of the
antiprogestin ZK 137 316, which permits normal ovarian/menstrual cyclicity,
has potential as a contraceptive in women.
相似文献
20.
Quantitative analysis of muscle fibre type and myosin heavy chain Distribution in the frog hindlimb: implications for locomotory design 总被引:2,自引:0,他引:2
Lutz Gordon J. Bremner Shannon Lajevardi Nahal Lieber Richard L. Rome Lawrence C. 《Journal of muscle research and cell motility》1998,19(7):717-731
To investigate the design of the frog muscular system for jumping, fibre type distribution and myosin heavy chain (MHC) isoform composition were quantified in the hindlimb muscles of Rana pipiens. Muscles were divided into two groups: five large extensor muscles which were predicted to shorten and produce mechanical power during jumping (JP), and four much smaller muscles commonly used in muscle physiology studies, but that do not shorten or produce power during jumping (NJP). Fibres were classified as one of four different types (type 1, 2, 3 or tonic) or an intermediate type (type 1–2) based ontheir relative myosin-ATPase reactivity and MHC immunoreactivity in muscle cross-sections according to previous nomenclature established for amphibian skeletal muscle. Type 1 fibres correspond to the fastest and most powerful of the twitch fibres, and type 3 fibres are the slowest and least powerful. Myosin-ATPase histochemistry revealed that the JP muscles were co mposed primarily of type 1 fibres (89%) with a small percentage of type 2 (7%) and intermediate type 1–2 fibres (4%). The fibre type composition of NJP muscles was more evenly distributed between type 1 (29%), type 2 (46%) and type 1–2 (24%) fibres. Tonic fibres comprised less than 2% of the muscle cross-section in both JP and NJP groups. Similarly, MHC composition determined by quantitative SDS–PAGE revealed that JP muscles were composed predominantly of type 1 MHC (86%), with a balance of type 2 MHC (14%). The opposite pattern was found for MHC composition in the NJP muscles: type 1 (28%), type 2 (66%) and type 3 (6%). These results demonstrate that the large extensor muscles that produce the power required for jumping have a fibre type distribution that enables them to generate high levels of mechanical power, with the type 1 isoform accounting for 85–90% of the total M HC content. 相似文献