Crichton E G, Hoyer P B, Krutzsch P H
Department of Anatomy, College of Medicine, University of Arizona, Tucson 85724.
Cell Tissue Res. 1990 May;260(2):355-66. doi: 10.1007/BF00318638.
In the leaf-nosed bat, Macrotus californicus, a 4.5-month period of delayed early embryogenesis (October-March) precedes a 3.5-month period of normal embryogenesis (March-June). This prolonged gestation provides a unique opportunity to correlate ovarian changes with the events following implantation. The present study investigated luteal cell development and follicular biology during gestation. Circulating progesterone (P) levels following implantation were unchanged before transition to normal development, and were maximal at the start of active gestation. Luteal cell diameters increased during this period. Serum P levels declined prior to parturition, when cells staining positive for 3 beta-hydroxy-5-steroid dehydrogenase-5,4-isomerase (3 beta-HSD) activity were reduced in number and diameter, and enzyme staining was less intense in tissue slices. Subcellular steroidogenic organelles were present during delayed development, but smooth endoplasmic reticulum (SER) was markedly increased after the resumption of normal development at which time also luteal cells reacted positively to staining for 17 beta-HSD. Before parturition, lipid droplet accumulation and reduced SER suggested a reduction in steroid secretion. Large multilaminar follicles stained positive for 3 beta-HSD activity throughout gestation and for 17 beta-HSD except in late delayed development. Thus, the delay in embryogenesis may be due to an inadequately developed corpus luteum or to the steroidogenic activity of the multilaminar follicles.
在加州叶鼻蝠（Macrotus californicus）中，4.5个月的早期胚胎发育延迟期（10月至次年3月）先于3.5个月的正常胚胎发育阶段（3月至6月）。这种延长的妊娠期为将卵巢变化与着床后事件相关联提供了独特的机会。本研究调查了妊娠期黄体细胞的发育和卵泡生物学。着床后循环孕酮（P）水平在过渡到正常发育前保持不变，在活跃妊娠期开始时达到最高值。在此期间黄体细胞直径增大。分娩前血清P水平下降，此时对3β-羟基-5-类固醇脱氢酶-5,4-异构酶（3β-HSD）活性染色呈阳性的细胞数量和直径减少，且组织切片中的酶染色强度降低。在发育延迟期存在亚细胞类固醇生成细胞器，但在恢复正常发育后滑面内质网（SER）显著增加，此时黄体细胞对17β-HSD染色也呈阳性反应。分娩前，脂滴积累和SER减少表明类固醇分泌减少。整个妊娠期大型多层卵泡对3β-HSD活性染色呈阳性，对17β-HSD染色呈阳性，但在发育延迟后期除外。因此，胚胎发育延迟可能是由于黄体发育不全或多层卵泡的类固醇生成活性所致。
