Prolactin is an anterior pituitary hormone involved in various physiological phenomenon including reproduction. The prolactin receptor (PRLR) is detected in diverse tissues such as brain, ovary, placenta and uterus in several mammalian species. A total of 227 pigs [Korean native pigs (KNP) 27; Landrace pigs 29; Korean native pigs x Landrace F1 91; Nanchuckmacdon pigs 80] were used to investigate the allele frequency difference of the prolactin receptor (PRLR) gene among the four pig lines. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) with Alu I restriction enzyme was used to determine the genotypes of PRLR. Frequencies of PRLR alleles among the four different pig lines were not significantly different (Chi-square=3.94, DF=3, P=0.27). A total of 40 Nanchuckmacdon pigs were used to investigate the effect of the prolactin receptor (PRLR) gene on total number of piglets born (TNB), number of piglets of alive (NBA) using general linear model implemented in MINITAB software. For TNB, the AB genotype had higher genotypic value (10.61) than the values of AA (9.83) and BB (10.30). Likewise, the AB genotype had higher genotypic value (8.96) than the values of AA (8.18) and BB (8.90) for NBA. However, these associations of the PRLR gene with TNB and NBA were not statistically significant. In conclusion, it is necessary to increase the sample size for investigating the effect of the PRLR gene on TNB and NBA in pigs.

MAC-T cells, bovine mammary epithelial cell line, have been utilized to investigate bovine lactation system. A lactogenic phenotype of the cell is generally induced by combination of dexamethasone, insulin and prolactin (PRL). Effect of vitamin A derivative retinoic acid (RA), well reported as an inducer for differentiation in many cells, to MAC-T cell has not been studied. The objective of this study was to confirm effect of differentiation potential by RA treatment in MAC-T cells and to test effect of combination of RA and PRL treatment. In RA or PRL treatment groups, both has induced morphological change to secrete milk of MAC-T cells. Combination of RA and PRL treatment group has presented noticeable lactogenic phenotype among the all group. This phenotype observed at four days after treatment and showed critical morphological change that was rouphly spherical structure at eight days. RA alone treatment showed slightly inhibition of proliferation in the MAC-T cells, but co-treatment with PRL was improved the cell growth more than control group. MTT assay result and Bcl-xL/Bax ratio of mRNA abundance also was entirely consistent with earlier one. RA-induced differentiation of MAC-T cells has increased αs1-casein, αs2-casein and β-casein mRNA expression compared to PRL treatment group. Expression of αs1-casein, αs2-casein and β-casein genes represented the maximum value in the combination of RA and PRL treatment group at four days. The value of each casein gene expression was 4-, 5.5- and 5.9-fold, respectively, as compared with PRL alone treatment in the MAC-T cells. Protein level of β-casein releasing to the medium also induced the highest level at four days. These results provide evidence that RA can induce the differentiation of MAC-T cells and have synergetic effect with PRL.

Domestic bitches are non-seasonally monoestrus; spontaneously ovulate only once or twice occurs at anytime of the year. Estrus induction has been applied infrequent estrus, misleading ovulation, mating difficulties, failure to conceive after normal mating, pregnancy failure and biological research. Protocol of estrus induction which included variable hormones such as FSH, GnRH, and PMSG have been applied for the last decades. Recently, Bromocriptine, one of anti-prolatin/dopamine agonist has been occasionally applied for estrus induction. The study was carried out to investigate the effective method for the induction of estrus in bitches using different hormone treatments, and the initiation time of estrus from hormone treatment by assessments of cytological observation and blood plasma progesterone concentration. A total of 54 bitches on anestrus were selected for the study and divided randomly into 8 treatment groups as follow. Control, natural estrus; FSH (L), FSH (1.5 mg/kg, twice a day, , Vetrepharm); FSH (H), FSH (3.0 mg/kg, twice a day); GnRH+FSH, GnRH (5 ug/kg, once first day, , Dongbang)+FSH (3 mg/kg, SID); PMSG, PMSG (50 IU/kg, every third day , Intevet); GnRH+PMSG, GnRH (5 ug/kg, only first day)+PMSG (50 IU/kg, every third day); GnRH, GnRH (5 ug/kg, only first day); Bromocriptine, bromocriptine (0.3 mg/kg, SID, , Novartis). The bitches were evaluated clinical sign, cytological exam and Premate for assessment of estrus induction. Estrus induction rates were significantly (P<0.05) higher in GnRH+PMSG (100%) compared to others. PMSG and GnRH+PMGS (87.5 and 100%) and Bromocriptine (77.8%) were higher than others except GnRH+PMSG. Analysis of vaginal smear has proved to be effective a correct assessment of estrus induction with assay of progesterone concentration by Premate. Proestrus initiated by the after induction in most case. In conclusion, bromocriptine is an effective drug for estrus induction in bitches and assay of progesterone concentration by Premate with examination of vaginal smear that should be useful to detection of estrus induction of estrus induced bitches.

Glucocorticoid는 비유기 동물의 유선세포 pro-lactin receptor(PRL-R) 발현을 증가시키며, 전반적인 유선세포의 유합성 작용을 활성시킴으로 유합성 능력을 증진시킨다. 유선세포 PRL-R 발현량 증가는 유생산량 향상과 밀접한 관계를 갖는다. 본 실험은 비유중기의 재래산양의 유합성 능력을 향상시키고자, 0.05. 0.1과 0.2 g hydrocortisone을 5ml의 생리식염수에 현탁하여, 정맥투여하고 유선세포 PRL-R와 -유

Prolactin (PRL) surge in cycling rats at proestrous afternoon has previously been reported as an inducer of apoptotic cell death of luteal cells. This death-inducing action of PRL seeins unusual, because PRL can he categorized as a cell-survival factor, if other known physiological functions of PRL are taken into account. In this study, the apoptotic action of PRL was assessed in cultured cells prepared from rat luteal tissue and underlying molecular /cellular mechanism of PRL-induced luteolysis was analyzed. The latest crop of corpora lutea (CLs) were enucleated from rat ovaries at 18:00 h on the proestrous day before the next ovulation. Donor rats were pretreated with CB154, a dopamine agonist, in order to he exempted from the endogenous PRL surge. The harvested GLs were dispersed and cultured with or without PRL (2g /ml) for 24 or 48 h. An addition of PRL to the culture medium changed the parameters indicative of cell death via apoptosis: a decrease in cell viability (MTT) and an increase in chromatin condensation. Most of the DNA breakdown in nuclei induced by PRL occurred in steroidogenic cells which were identified by 3-HSD activity staining, and the number of 3-HSD-positivecells were significantly decreased. Interestingly, most of the cells with an apoptotic nucleus adhered to one or more intact and seemingly non-steroidogenic cells. Because the expression of Fas has heen shown to be abundant in murine ovary, and Fas is known to have an exact physiological role in occurrence of apoptotic cell death, the membrane form-Fas ligand (rnFasL) was quantified in the cell lysate. An addition of PRL increased expression of mFasL. Moreover, an addition of concanavalin A (ConA), a T-cell specific activator, in place of PRL, enhanced the apoptotic parameters. Cumulatively, the apoptotic PRL action was addressed to cells unknown than steroidogenic lute~ cells. The most prohable candidate for the direct target cells is Tcells in the luteal tissue that can express mFasL in response to PRL.

We investigated the effect of light spectra on circadian rhythm by exogenous prolactin (PRL) by using light emitting diodes (LEDs): red, green, and purple. We injected PRL into live fish or treated cultured brain cells with PRL. We measured changes in the expressions of period 2 (Per2), cryptochrome 1 (Cry1), melatonin receptor 1 (MT1) mRNAs, and MT1 proteins, and in the plasma PRL, serotonin, and melatonin levels. After PRL injection and exposure to green LED light, MT1 expression and plasma melatonin levels were significantly lower, but the expressions of Per2 and Cry1 were significantly higher than others. Plasma serotonin after PRL injection and exposure to red LED light was significantly lower than others. These results indicate that injection of high concentration PRL inhibits melatonin, and inhibited melatonin regulates circadian rhythm via clock genes and serotonin. Thus, exogenous PRL regulates the circadian rhythm and light spectra influence the effect of PRL in goldfish.

망간은 정소 독성을 나타내며, 뇌기저핵에 작용하여 혈청 프로락틴의 농도를 증가시킨다. 그리고 혈청 프로락틴 농도 상승에 의한 과프로락틴혈증(hyperprolactinemia)은 정소의 정자 생성을 억제한다. 본 연구에서는 망간의 전신 노출이 흰쥐 정소의 정자 생산과 혈청 프로락틴 농도에 미치는 영향을 조사하기 위하여 실험동물을 대조군 과 망간 노출군 (Mn )으로 나누고, 노출군은 다시 노출 기간에 따라 4주와 13주 노출군 등 4군으로 분류하였다(n=