Histology of the one-humped camel’s uterus and vagina during the follicular and luteal phases of the oestrous cycle

Abstract

The dromedary camel is one of the domestic animals that have not received adequate scientific attention. Unlike other domestic animals, the dromedary camel does not ovulate spontaneously until after a successful mating. Therefore, present study seeks to evaluate the histological features of the vagina and the uterus of dromedary camel during follicular and luteal phases of the oestrous cycle. A total of 86 one-humped camels were included, and their blood samples were collected for progesterone assay. The progesterone assay enabled us to divide the camels into the follicular and luteal phase groups, according to progesterone concentration standards for luteal and follicular phase of the oestrous cycle. In the specimen collected during the follicular phase, the mean serum progesterone level was 0.89±16 ng/ml, while its level was 1.61±0.81 ng/ml in the specimen during the luteal phase. Animals with P4 values <1 ng/ml (n=51, mean of 0.89 ± 0.16ng/ml) and those with P4 values >1 ng/ ml (n=35, mean of 1.61 ± 0.81 ng/ml) were considered to be in follicular and luteal phase, respectively. Vaginal and uterine tissue samples were collected from all members of both groups. The histological features observed in the uterus during the follicular phase are presented with a layer of simple columnar epithelium with fewer elastic epithelial cells. In the uterine lamina propria, there are several visible tubular glands. Blood vessels are conspicuous and clogged. The inner circular and outer longitudinal layers of the muscle bands are thick, with numerous interstitial spaces. There are more intercellular gaps in the vagina than in the uterus. On the other hand, in the sample collected during the luteal phase, uterine tissue is consisted of simple columnar epithelium. The glands in the lamina propria are more coiled and tubular. Luteal phase is also characterized by the presence of congested blood vessels that are thick in appearance. Thick and clogged blood arteries in the uterus have also been observed. The uterine muscle layer consists of separate inner circular and outer longitudinal layers. It is also thicker than the one observed in the follicular phase. This detailed histological study of vagina and uterus will not only help to understand the reproductive status of camel, but it will also assist in pathological evaluation of the reproductive tract.