Sudson Sirivaidyapong

Differential expression of Toll-like receptor 4 (TLR4) in healthy and infected canine endometrium

This study provides the first report into immunohistochemical localization of Toll-like receptor (TLR) in the canine reproductive tract. TLR4 was investigated in endometrium during the estrous cycle and in pyometra. Pyometra is the most important pathological condition of the uterus due to bacterial infection in dogs. To protect against invading pathogens, the female reproductive tract has evolved immune mechanisms. TLRs are the cellular components of the afferent arm of the innate immune system. The expression of TLR4 was significantly higher in the endometrial stroma compared to the endometrial surface epithelium and glandular epithelium in proestrus. The glandular epithelium and stroma at the diestrous stage expressed TLR4 significantly higher than surface epithelium. Furthermore, when compared to other healthy groups, the glandular epithelium at diestrus also higher expressed TLR4 than other stages. The expression of TLR4 in the surface epithelium was higher in dogs with pyometra compared with all other groups. And, the surface epithelium of dogs suffering from pyometra also expressed TLR4 more intensely than the glandular epithelium. The innate immunity of infected canine endometrium response to bacterial infection is intensely extremely increased by the expression of TLR4. Furthermore, the different levels of TLR4 expression seems related to physiological changes in distinct cell types of endometrium, leukocytes populations, cytokines and sex hormones.

The number of ERα and PR in the mammary glands of bitches with and without tumor mass using immunohistochemical assay

The objectives of this study were to evaluate the expressions of estrogen receptors alpha (ERα) and progesterone receptors (PR) in histologically normal and tumoral canine mammary tissues within the same bitch and to correlate between the immunohistochemical staining scores of both receptors and duration of tumor growth. Twelve tumoral and contralateral normal mammary tissues, both determined by histology were surgically obtained from 12 dogs. The expressions of ERα and PR were evaluated by avidin–biotin–peroxidase complex (ABC) method and ERα and PR scores were calculated. The expressions of the ERα and the PR between normal and tumoral mammary tissues were not significantly different. The PR expression and duration of tumor growth showed a significantly inverse correlation. A positive correlation was found between the number of the ERα and the PR in both normal and tumoral mammary tissues which may indicate that either ERα or PR could be used as a prediction of hormonal therapy parameter in dogs. However, the information of ERα and PR status as well as hormonal therapy is not routinely available in veterinary medicine and it appears that half of the mammary tumors from the present study are hormone-independent tumors (ERα and PR negative). Therefore, the treatment of canine mammary tumor by hormonal therapy should be carefully considered.

GnRH-agonist implantation of prepubertal male cats affects their reproductive performance and testicular LH receptor and FSH receptor expression.

This study was conducted to investigate the effect of GnRH-agonist implantation in prepubertal tomcats on sexual behavior, reproductive performance, and expression of testicular LH receptor (LHR) and FSH receptor (FSHR) and also to compare the testicular characteristics, LHR and FSHR expression between prepubertal and adult tomcats. In experiment 1, 3-month-old tomcats (n = 6/group) were either treated with or left without 4.7 mg deslorelin implants. Semen collection and evaluation were performed just before castration at 48 weeks after treatment; removed testes were analyzed for mRNA and protein expression of LHR and FSHR. We were able to collect semen from six non-treated cats, whereas in treated cats, semen was uncollectable. The results revealed that sexual behavior was absent in the implanted cats throughout the study period. Testicular volume was found to decrease from 30 weeks after treatment onward in the implanted cats compared to the controls (P < 0.05). Semen production was found only in non-implanted cats. Testicular tissue score, seminiferous tubule diameter, and LHR protein expression were found lower in the implanted cats (P < 0.05), but no differences were observed in mRNA expression of LHR and protein expression of FSHR between groups. The mRNA expression of FSHR was higher in the implanted (P < 0.05) compared to control cats. In experiment 2, testes from prepubertal (n = 6) and adult (n = 6) male cats were collected after castration and analyzed for mRNA and protein expression of LHR and FSHR. No differences were observed in the protein expression of LHR and FSHR between the two groups, whereas mRNA expression of FSHR was higher in prepubertal cats (P < 0.05). Testicular and epididymal weight, diameter of seminiferous tubules, and the testicular grade were higher in the adult compared to prepubertal cats (P < 0.05). In conclusion, deslorelin implants suppressed protein expression of LHR and enhanced mRNA expression of FSHR along with suppression of reproductive function without any adverse effects for at least 48 weeks in male cats.

Estrogen receptor alpha (ERα) and progesterone receptor (PR) in the mammary gland of bitches during different stages of estrous cycle

The objective of this study was to evaluate the estrogen receptor alpha (ERα) and progesterone receptor (PR) expressions in normal mammary tissues of bitches during different stages of the estrous cycle. Mammary tissues were collected from five beagle bitches at six different estrous stages for each bitch, which were: anestrus, proestrus, estrus, early diestrus, mid diestrus, and late diestrus. The expressions of ERα and PR were evaluated by avidin–biotin–peroxidase complex (ABC) method, and ERα and PR scores were calculated. The lowest scores of ERα and PR were found in mammary tissue collected during mid diestrus, whereas the ERα and PR scores were significantly higher during estrus and proestrus. A significantly higher score of the PR during anestrus compared to during mid diestrus was also observed, but this was not found for ERα score. In addition, positive correlation between ERα and PR scores were found which indicated that the presence of ERα and PR may be under the same regulatory mechanism. In conclusion, these findings suggested that ovarian steroid hormones, estrogen and progesterone, which differed during the stages of the estrous cycle may have a regulatory role in ERα and PR expression in bitch mammary gland.