Parotid secretion patterns during meals and their relationships to the tonicity of body fluids and to gastrin and pancreatic polypeptide in sheep
Parotid secretion patterns during meals and their relationships to the tonicity of body fluids and to gastrin and pancreatic polypeptide in sheep
复制标题
绵羊进餐时腮腺的分泌模式及其与体液张力、胃泌素和胰多肽的关系
DOI：
10.1079/bjn19900118
复制
发表时间：
1990
影响因子：
3.6
通讯作者：
G. Greenberg
中科院分区：
文献类型：
--
作者：
R. Carter;W. Grovum;G. Greenberg
比较了800g紫花苜蓿干草作为1、2、4、8种不同膳食时绵羊单侧腮腺唾液的流动规律。这些模式与瘤胃液和血浆的张力变化以及血浆中胃泌素和胰多肽的浓度有关。自由使用干草过夜的绵羊从早上8点到9点给绵羊提供新鲜干草，然后按照计划给予一、两、四或八餐新鲜干草，即每餐频率大小的平均剥夺时间为6.5h。唾液流率的峰值和峰值的时间在不同的膳食大小之间都不同。流速在进餐后3.2分钟达到最大值后迅速下降。饲喂7分钟后，血浆和瘤胃液的紧张度分别仅增加2.2和8.2摩尔/公斤。这些增加不会导致进食3.2分钟后观察到的腮腺流量迅速下降。餐后颈静脉血浆胃泌素浓度无明显变化。但从开始进食前16分钟至4分钟，上述指标均显著升高(P=0.0043)。餐后4.5min血浆胰多肽浓度出现峰值。然而，在这种肽的浓度恢复到喂养前的水平后，腮腺的流量仍然很低。在进餐早期观察到的腮腺分泌速度的快速下降可能是由于中枢兴奋的消退，而不是限制产生的抑制因素。
The flow pattern of unilateral parotid saliva in sheep was compared when a total of 800 g lucerne (Medicago sativa) hay was offered as one, two, four or eight distinct meals. These patterns were related to changes in the tonicity of rumen fluid and plasma and to plasma concentrations of gastrin and pancreatic polypeptide. Sheep having ad lib access to hay overnight were offered fresh hay from 08.00 to 09.00 hours and were then given one, two, four or eight meals of fresh hay according to a schedule such that the mean deprivation period was 6.5 h for each meal frequency-size. Neither the peak in saliva flow rate nor the time of this peak differed among the different meal sizes. The flow rate decreased rapidly after reaching a maximum at 3.2 min into the meal. After 7 min of eating, the tonicity of plasma and rumen fluid had increased by only 2.2 and 8.2 mosmol/kg respectively. These increases would not cause the rapid decline in parotid flow observed after 3.2 min of eating. There was no postprandial change in the concentration of gastrin in jugular plasma. However, it did increase significantly (P = 0.0043) from 16 to 4 min before eating commenced. There was a postprandial peak in plasma pancreatic polypeptide concentration after 4.5 min of eating. However, the parotid flow rate remained low after the concentration of this peptide returned to prefeeding levels. The rapid decrease in parotid secretion rate observed early in the meal may be due to subsiding central excitation rather than to an inhibitory factor limiting production.