Little G J, Bryden M M
Department of Anatomy, University of Queensland, St Lucia, Australia.
J Pineal Res. 1990;9(2):139-48. doi: 10.1111/j.1600-079x.1990.tb00702.x.
In the newborn southern elephant seal the pineal gland is very large, and both pineal and plasma melatonin concentration is elevated. The pineal gland was investigated during the first 24 h, and up to 20 days of age, in elephant seal pups. A primary aim of this investigation was to determine whether there are obvious ultrastructural characteristics of pinealocytes that are exhibiting extraordinarily high levels of activity. Blood and pineal glands were collected from thirty seven pups of known age which were sampled at random from early September to early November (1985) at Macquarie Island. The pineal gland is large (mean weight, 4.71 +/- 0.35 gm, range 1-9.3 gm) and actively secreting melatonin at birth. Melatonin concentrations were extremely variable, yet very high in pups during the first 24 h post-partum. Mean melatonin plasma concentration for pups 0-24 h was 17632.8 +/- 5723.8 pmol/l (4090.8 +/- 1327.9 pg/ml), ranging from 126 pmol/l (29 pg/ml) to 297000 pmol/l (68904 pg/ml). Electron microscopic examination did not reveal any marked changes in pinealocyte ultrastructure suggestive of increased secretory activity during this period. The large and extremely active pineal gland in newborn southern elephant seal suggests that it is actively involved in thermoregulation.
新生的南象海豹松果体非常大，松果体和血浆中的褪黑素浓度均升高。对南象海豹幼崽出生后头24小时以及直至20日龄期间的松果体进行了研究。本研究的一个主要目的是确定松果体细胞是否存在明显的超微结构特征，以表明其处于异常高的活动水平。从已知年龄的37只幼崽身上采集了血液和松果体，这些幼崽于1985年9月初至11月初在麦夸里岛随机取样。松果体很大（平均重量为4.71±0.35克，范围为1 - 9.3克），在出生时就积极分泌褪黑素。褪黑素浓度变化极大，但在产后头24小时内幼崽体内的浓度非常高。0 - 24小时幼崽的血浆褪黑素平均浓度为17632.8±5723.8皮摩尔/升（4090.8±1327.9皮克/毫升），范围从126皮摩尔/升（29皮克/毫升）到297000皮摩尔/升（68904皮克/毫升）。电子显微镜检查未发现松果体细胞超微结构有任何明显变化表明在此期间分泌活动增加。新生南象海豹中巨大且极其活跃的松果体表明它积极参与体温调节。
