Hallbäck D A, Jodal M, Lundgren O
Acta Physiol Scand. 1979 Apr;105(4):469-80. doi: 10.1111/j.1748-1716.1979.tb00112.x.
The vascular anatomy of the filiform and fungiform papillae of the feline tongue was studied by i.a. injection of India ink. Vascular loops of various appearances were found in the types of papillae studied, i.e. the large and the small filiform papillae and the fungiform ones. Such hairpin loops may function as countercurrent exchangers and to test this hypothesis tissue osmolality was determined in the papillae, while exposing them to various isotonic electrolyte solutions. The large filiform papillae with a vascular arrangement similar to that of intestinal villi exhibited a marked osmolar gradient from tip to base when exposed to a solution containing both glucose and sodium. If sodium and/or glucose was excluded from the solution, tissue osmolality was significantly decreased. This was also the case when the chloride ions of the solution was substituted with sulphate. The small filiform papillae are only provided with one or a few capillary loops. They exhibited a less marked osmolar gradient than the large ones and one of the different electrolyte solutions decreased the gradient. In the fungiform papillae a tissue hyperosmolality at the tip was also demonstrated. It is proposed that the papillary epithelium is provided with active transport mechanism(s) and that the papillary vessels function as countercurrent multipliers. The functional importance of these mechanisms are tentatively discussed.
通过向猫舌丝状乳头和菌状乳头注射印度墨水等方法，对其血管解剖结构进行了研究。在所研究的乳头类型中，即大、小丝状乳头和菌状乳头中，发现了各种形态的血管袢。这种发夹样袢可能起到逆流交换器的作用，为验证这一假设，在将乳头暴露于各种等渗电解质溶液的同时，测定了乳头中的组织渗透压。大丝状乳头的血管排列与肠绒毛相似，当暴露于含有葡萄糖和钠的溶液中时，从尖端到基部呈现出明显的渗透压梯度。如果溶液中不含钠和/或葡萄糖，组织渗透压会显著降低。当溶液中的氯离子被硫酸根取代时，情况也是如此。小丝状乳头仅配有一个或几个毛细血管袢。它们呈现出的渗透压梯度不如大丝状乳头明显，且一种不同的电解质溶液会降低该梯度。在菌状乳头中，也证实了尖端存在组织高渗现象。有人提出，乳头上皮具有主动转运机制，乳头血管起到逆流倍增器的作用。并初步讨论了这些机制的功能重要性。
