Dunlap C E, Sundberg D K, Rose J C
Peptides. 1985 May-Jun;6(3):483-9. doi: 10.1016/0196-9781(85)90114-7.
Enkephalin immunoreactive material from adrenal glands was characterized both in maternal and fetal sheep at various gestational ages. Whole gland extracts from both maternal and fetal sheep contained three major peaks of Enk immunoreactivity corresponding to apparent molecular weights of 10,000, 2800, and less than 1200 daltons. The majority of maternal adrenal Enk immunoreactivity was found in medullary tissue, although cortex also contained low but detectable amounts. This was also the case in newborn lambs and 139 day fetuses, where adrenal cortex was sufficiently developed to allow extraction and quantitation of opioid material. In fetuses at mid-gestation (70-80 days), adrenal medullary Enk immunoreactivity was approximately 75% of maternal values. Met-Enk and Leu-Enk content in 139 day fetal medulla were 70 and 76% of maternal values respectively, while newborn Met- and Leu-Enk medullary content were similar to maternal values. The molar ratio of Met-Enk to Leu-Enk was approximately 4:1 in both maternal and fetal adrenal medulla, and 2:1 in adrenal cortex, suggesting different synthetic processing of opioid peptides in the two tissues. The early appearance of significant levels of adrenal medullary Enk immunoreactivity and subsequent development paralleling that of catecholamines suggest a predominant role for adrenal enkephalins in regulation of fetal cardiovascular function early in gestation.
对不同妊娠阶段母羊和胎羊肾上腺中的脑啡肽免疫反应性物质进行了表征。母羊和胎羊的全腺提取物中含有三个主要的脑啡肽免疫反应性峰，其表观分子量分别为10,000、2800和小于1200道尔顿。母羊肾上腺的脑啡肽免疫反应性大部分存在于髓质组织中，尽管皮质中也含有少量但可检测到的量。新生羔羊和139天龄胎儿的情况也是如此，此时肾上腺皮质已充分发育，能够提取和定量阿片类物质。在妊娠中期（70 - 80天）的胎儿中，肾上腺髓质的脑啡肽免疫反应性约为母羊的75%。139天龄胎儿髓质中的甲硫氨酸脑啡肽（Met-Enk）和亮氨酸脑啡肽（Leu-Enk）含量分别为母羊的70%和76%，而新生羔羊髓质中的Met-Enk和Leu-Enk含量与母羊相似。母羊和胎羊肾上腺髓质中Met-Enk与Leu-Enk的摩尔比约为4:1，肾上腺皮质中为2:1，这表明两种组织中阿片肽的合成加工方式不同。肾上腺髓质中脑啡肽免疫反应性显著水平的早期出现以及随后与儿茶酚胺平行的发育表明，肾上腺脑啡肽在妊娠早期胎儿心血管功能调节中起主要作用。
