Gemmell R T, Nelson J
Department of Anatomy, University of Queensland, St. Lucia, Brisbane, Australia.
Anat Embryol (Berl). 1988;177(5):395-402. doi: 10.1007/BF00304736.
The ultrastructure of the pituitary glands of the newborn northern native cat, brushtail possum and the northern brown bandicoot and the adrenal glands of the former two marsupials were examined to determine whether these endocrine glands were functional at birth. The anterior pituitary of all three species was well vascularised and many cells contained electron-dense, membrane bound granules. The adrenal glands were composed of two distinct cell populations. One group of cells possessed dark staining granules, normally observed in catecholamine-secreting cells, and the second group contained large amounts of smooth endoplasmic reticulum and mitochondria with tubulovesicular cristae, indicative of steroid hormone secreting cells. The ultrastructure of the cells of the fetal pituitary and adrenal of all three species would suggest that these glands are functional at birth and, as with many eutherians, the marsupial pituitary and adrenal gland may play an important role in determining the length of gestation.
对新生北方袋狸、帚尾袋貂和北褐袋鼹的垂体超微结构以及前两种有袋动物的肾上腺进行了检查，以确定这些内分泌腺在出生时是否具有功能。所有这三个物种的垂体前叶血管丰富，许多细胞含有电子致密的、膜结合的颗粒。肾上腺由两种不同的细胞群组成。一组细胞含有深色染色颗粒，这通常在分泌儿茶酚胺的细胞中观察到，第二组细胞含有大量的滑面内质网和具有管状嵴的线粒体，这表明是分泌类固醇激素的细胞。所有这三个物种的胎儿垂体和肾上腺细胞的超微结构表明，这些腺体在出生时具有功能，并且与许多真兽类动物一样，有袋动物的垂体和肾上腺可能在确定妊娠期长度方面发挥重要作用。
