Laboratorio di Cronofisiologia Veterinaria, Dipartimento di Scienze Sperimentali e Biotecnologie Applicate, Facoltà di Medicina Veterinaria, Università degli Studi di Messina, Polo Universitario dell'Annunziata, 98168, Messina, Italy.
J Comp Physiol B. 2010 Aug;180(6):895-904. doi: 10.1007/s00360-010-0462-1. Epub 2010 Mar 12.
We asked whether, during the postnatal period, the daily patterns of body temperature (Tb), heart rate (HR) and breathing frequency (f) begin and develop in synchrony. To this end, measurements of HR, f and Tb were performed weekly, on two consecutive days, for the first two postnatal months on puppies of three breeds of dogs (Rottweiler, Cocker Spaniel and Carlino dogs) with very different birth weights and postnatal growth patterns. Ambient conditions and feeding habits were constant for all puppies. The results indicated that (1) the 24-h average Tb increased and average HR and f decreased with growth, (2) the daily rhythms in Tb were apparent by 4 weeks, irrespective of the puppy's growth pattern, (3) the daily rhythm of Tb in the puppy was not necessarily following that of the mother; in fact, it could anticipate it. (4) The daily rhythms in HR and f were not apparent for the whole study period. We conclude that in neonatal dogs the onset of the daily rhythms of Tb has no obvious relationship with body size or rate of growth and is not cued by the maternal Tb rhythm. The daily rhythms of HR and f do not appear before 2 months of age. Hence, they are not in synchrony with those of Tb.
我们研究了在产后阶段，体温（Tb）、心率（HR）和呼吸频率（f）的日周期是否同步开始和发展。为此，我们对三种犬种（罗特韦尔犬、可卡犬和卡尔罗犬）的幼犬在产后两个月内每周进行两次连续两天的 HR、f 和 Tb 测量，这些幼犬的出生体重和产后生长模式差异很大。所有幼犬的环境条件和喂养习惯都是相同的。结果表明：（1）24 小时平均 Tb 随生长而增加，平均 HR 和 f 随生长而降低；（2）无论幼犬的生长模式如何，4 周时 Tb 的昼夜节律都很明显；（3）幼犬的 Tb 昼夜节律并不一定与母体的昼夜节律同步；事实上，它可能会提前。（4）整个研究期间，HR 和 f 的昼夜节律都不明显。我们的结论是，在新生幼犬中，Tb 的昼夜节律的开始与体型或生长速度没有明显的关系，也不受母体 Tb 节律的影响。HR 和 f 的昼夜节律在 2 个月大之前不会出现。因此，它们与 Tb 的昼夜节律不同步。
