Apgar J
J Nutr. 1977 Aug;107(8):1399-403. doi: 10.1093/jn/107.8.1399.
The effects on parturition of a low zinc diet during pregnancy and of three levels of zinc repletion late in pregnancy were compared in two strains of rats, Sprague Dawley and Long Evans. Long Evans rats had a higher hematocrit and higher plasma protein levels than did Sprague Dawley rats. Long Evans rats also had heavier mammary glands and tended to deliver somewhat later than the Sprague Dawley rats. Weight gains during pregnancy and weights of the liver, spleen, adrenal glands, and pups did not vary between strains. No differences were detectable in the degree of stress at parturition between the unsupplemented females of the two strains. Injection of 300, 600, or 900 microgram zinc on day 18 of pregnancy increased female weight gains, pup weight, and spleen and mammary gland weights, and decreased hematocrit level. Three females in the unsupplemented groups died about the expected time of parturition; none died in the supplemented groups. Although there were some differences between the strains, the effects of a low zinc diet and the requirement for zinc for normal parturition were the same in the two strains. An injection of 900 microgram zinc on day 18 resulted in normal parturition in both strains.
在两种品系的大鼠（斯普拉格·道利大鼠和朗·埃文斯大鼠）中，比较了孕期低锌饮食以及孕期后期三种锌补充水平对分娩的影响。朗·埃文斯大鼠的血细胞比容和血浆蛋白水平比斯普拉格·道利大鼠高。朗·埃文斯大鼠的乳腺也更重，并且分娩时间往往比斯普拉格·道利大鼠稍晚。两品系大鼠在孕期的体重增加以及肝脏、脾脏、肾上腺和幼崽的重量没有差异。在两种品系未补充锌的雌性大鼠分娩时的应激程度方面未检测到差异。在妊娠第18天注射300、600或900微克锌可增加雌性大鼠的体重增加、幼崽体重以及脾脏和乳腺的重量，并降低血细胞比容水平。未补充锌组中有三只雌性大鼠在预期分娩时间左右死亡；补充锌组中无一死亡。尽管两品系之间存在一些差异，但低锌饮食的影响以及正常分娩对锌的需求在两品系中是相同的。在妊娠第18天注射900微克锌可使两品系大鼠均正常分娩。
