Preventive effects of CIDR-based protocols on premature ovulation before timed-AI in Ovsynch in cycling beef cows

Ovsynch is a program developed to synchronize ovulation for timed breeding. In this paper, the authors investigate whether controlled internal drug release (CIDR)-based protocols prevent premature ovulation before timed-artificial insemination (AI) when Ovsynch is started a few days before luteolysis in cycling beef cows. Nine beef cows at 16 days after oestrus were treated with (1) Ovsynch, i.e. gonadotropin releasing hormone (GnRH) analogue on day 0, prostaglandin (PG) F(2alpha) analogue on day 7 and GnRH analogue on day 9 with timed-AI on day 10, (n=3); (2) Ovsynch+CIDR (Ovsynch protocol plus a CIDR for 7 days from day 0, n=3), or (3) oestradiol benzoate (OB)+CIDR+GnRH (OB on day 0 in lieu of the first GnRH treatment, followed by the Ovsynch+CIDR protocol, n=3). In the Ovsynch group (1) plasma progesterone concentrations fell below 0.5 ng/mL earlier (day 5) than in both CIDR-treated groups (2) and (3), where this occurred on day 8. Plasma oestradiol-17beta concentrations peaked on day 8 in the Ovsynch group and on day 9 in both CIDR-treated groups. The dominant follicle ovulated on day 10 in the Ovsynch group and on day 11 in both CIDR-treated groups. Thus, both CIDR-based protocols prevented premature ovulation before timed-AI in Ovsynch when the protocol was started a few days before luteolysis. This reflects the fact that progesterone levels remained high until the beef cattle were treated with PGF(2alpha).

Reduction of mucin-1 gene expression associated with increased Escherichia coli adherence in the canine uterus in the early stage of dioestrus

The relation between adherence of Escherichia coli and expression of mucin-1 (Muc1: an integral membrane mucin) mRNA in the endometrium was studied in beagle bitches at different stages of the oestrous cycle and in those with cystic endometrial hyperplasia/pyometra complex (pyometra). The number of E. coli adhering to the endometrium was low at pro-oestrus and oestrus and increased at the early stage (day 10) of dioestrus, corresponding to the implantation period; it declined thereafter. Adhesion of the organisms to endometrial epithelial cells collected at day 10 of dioestrus was inhibited by the addition of D-mannose. When endometrial epithelial cells collected at pro-oestrus were treated with hyaluronidase, an enzyme that digests mucins, the numbers of E. coli adhering to the cells tended to increase. With polymerase chain reaction analysis it was possible to detect Muc1 gene transcripts in the endometrium at all stages of the oestrous cycle, although the level of Muc1 mRNA decreased by day 10 of dioestrus. The levels of Muc1 mRNA in bitches with a clinical stage of pyometra were low and comparable to those at day 10 of dioestrus. The number of E. coli adhering to the endometrium and Muc1 mRNA levels in the endometrium were inversely correlated (r=-0.77, P<0.01). Immunohistochemical analysis showed little staining for Muc1 in the endometrial epithelia at day 10 of dioestrus and in bitches with pyometra. These results suggest that reduction of Muc1 expression is associated with increased E. coli adherence in the canine uterus at the early stage of dioestrus, possibly facilitating the development of pyometra.

Inhibitory Effects of CIDR-based Ovulation-synchronization Protocols on Uterine PGF2.ALPHA. Secretion at the Following Luteal Phase in Early Postpartum Non-cycling Beef Cows

We investigated whether CIDR-based ovulation-synchronization protocols inhibit secretion of prostaglandin (PG) F2alpha from the uterus in the following luteal phase in non-cycling beef cows. Ten early (a month) postpartum non-cycling Japanese Black beef cows were treated with (1) Ovsynch (GnRH analogue on Day 0, PGF2alpha analogue on Day 7, and GnRH analogue on Day 9; n=3), (2) Ovsynch+CIDR (Ovsynch protocol plus a CIDR for 7 days from Day 0; n=4), or (3) estradiol benzoate (EB) Ovsynch+CIDR (EB on Day 0 in lieu of the first GnRH treatment followed by the Ovsynch+CIDR protocol; n=3). An oxytocin challenge was administered on Day 24 to examine uterine PGF2alpha secretion. Plasma concentrations of 13,14-dihydro-15-keto- PGF2alpha were lower at 30-120 min after oxytocin administration in the Ovsynch+CIDR group and 75 min after administration in the EB Ovsynch+CIDR group than in the Ovsynch group (P<0.05). Plasma progesterone concentrations were higher from Days 1 to 7 in the Ovsynch+CIDR group and from Days 1 to 5 in the EB Ovsynch+CIDR group than in the Ovsynch group (P<0.05). The progesterone concentrations were higher on Days 27 and 29 in both CIDR-treated groups than in the Ovsynch group (P<0.05). In conclusion, in non-cycling beef cows, CIDR-based ovulation-synchronization protocols inhibit uterine PGF2alpha secretion in the following luteal phase and prevent premature luteolysis as is seen with the Ovsynch protocol.

Relations between Plasma IGF-I Concentrations during Treatment with CIDR-based or Ovsynch Protocol for Timed AI and Conception in Early Postpartum Japanese Black Beef Cows

We examined the relations between plasma insulin-like growth factor (IGF) -I concentrations during treatment with CIDR-based or Ovsynch protocol for timed AI and conception and plasma steroid concentrations in early postpartum Japanese Black beef cows. Cows in the control group (Ovsynch; n = 21) underwent Ovsynch protocol (GnRH analogue on Day 0, PGF(2alpha) analogue on Day 7, and GnRH analogue on Day 9), with AI on Day 10, approximately 20 h after the second GnRH treatment. Cows in the Ovsynch+CIDR group (n = 22) received Ovsynch protocol plus a CIDR for 7 days (starting on Day 0). Cows in the further treatment group (EB+CIDR+GnRH; n = 22) received 2 mg of estradiol benzoate (EB) on Day 0 in lieu of the first GnRH treatment, followed by the same treatment as in the Ovsynch+CIDR protocol. Plasma IGF-I concentrations were determined on Days -7, 0, 7, 9 and 17. Conception rates were improved in the CIDR-combined groups (both CIDR-treated groups were combined) relative to Ovsynch group (P < 0.05) for cows with low IGF-I concentrations (<1,000 ng/ml) on Days -7, 0, and 7, but improved conception rate produced by the CIDR-based protocols did not occur in cows with a high IGF-I concentration (> or =1,000 ng/ml). Plasma estradiol-17beta concentrations increased from Day 0 to 7 (P < 0.05) and were unchanged from Day 7 to 9 in the Ovsynch group with low IGF-I concentrations on Day 0, while they were unchanged from Day 0 to 7 and increased from Day 7 to 9 (P < 0.05) in the Ovsynch group with high IGF-I concentrations on Day 0 and in the CIDR-combined group. Plasma progesterone concentrations in the Ovsynch group with low IGF-I concentrations on Day 0 were higher on Day 14 than in the Ovsynch group with high IGF-I concentrations on Day 0 and in the CIDR-combined group (P < 0.05). In conclusion, CIDR-based protocols may improve conception relative to Ovsynch in early postpartum beef cows with lower plasma IGF-I concentrations at the start of the protocols. This improvement is probably due to prevention of premature increases of estradiol-17beta and progesterone concentrations, which occurred in cows with low IGF-I concentrations treated with Ovsynch, by the CIDR treatment.

Effect of CIDR-based protocols for timed-AI on the conception rate and ovarian functions of Japanese Black beef cows in the early postpartum period

Our objectives were to compare: (1) conception rates (in early postpartum Japanese Black beef cows) to timed-artificial insemination (timed-AI) among Ovsynch and Ovsynch plus CIDR protocols, and a protocol that used estradiol benzoate (EB) in lieu of the first GnRH of the Ovsynch plus CIDR; and (2) the effects of these protocols on blood concentrations of ovarian steroids. Cows in the control group (Ovsynch; n=35) underwent a standard Ovsynch protocol (GnRH analogue on Day 0, PGF(2 alpha) analogue on Day 7 and GnRH analogue on Day 9), with timed-AI on Day 10, approximately 20 h after the second GnRH treatment. Cows in the Ovsynch+CIDR group (n=31) received a standard Ovsynch protocol plus a CIDR for 7 days (starting on Day 0). Cows in the third treatment group (EB+CIDR+GnRH; n=41) received 2mg of EB on Day 0 in lieu of the first GnRH treatment, followed by the same treatment as in the Ovsynch+CIDR protocol. The conception rate tended to be greater in the Ovsynch+CIDR group (67.7%, P<0.15) and was greater in the EB+CIDR+GnRH (73.2%, P<0.05) and CIDR-combined (both CIDR-treated groups were combined) groups (70.8%, P<0.05) than in the Ovsynch group (48.6%). Plasma progesterone concentrations were higher on Day 7 (P<0.01) and lower on Days 14, 17 and 21 (P<0.001) in the CIDR-combined group than in the Ovsynch group. Plasma estradiol-17beta concentrations were higher on Day 7 in the Ovsynch group of non-pregnant cows than in the CIDR-combined group of non-pregnant cows and in an all-combined group (all treatment groups combined) of pregnant cows (P<0.01). Furthermore, estradiol-17beta concentrations were lower on Day 9 in the Ovsynch and CIDR-combined groups of non-pregnant cows than in the all-combined group of pregnant cows (P<0.05). In conclusion, both protocols using CIDR improved conception rates following timed-AI in early postpartum suckled Japanese Black beef cows relative to the Ovsynch protocol. Treatment with a CIDR may prevent early maturation of follicles observed in non-pregnant cows treated with the Ovsynch protocol, by maintaining elevated blood progesterone concentrations until PGF(2 alpha) treatment.

Detection of transforming growth factor-alpha and epidermal growth factor receptor mRNA and immunohistochemical localization of the corresponding proteins in the canine uterus during the estrous cycle

Uterine expression of the epidermal growth factor (EGF) family of growth factors has not been studied in the dog. The present study looks at the presence of mRNA transcripts and immunohistochemical localization for transforming growth factor-alpha (TGF-alpha), which is the potent EGF family member, and for EGF receptor (EGF-R) in the canine uterus during the estrous cycle. The reverse transcriptase-polymerase chain reaction together with sequencing of the products confirmed the presence of their mRNA transcripts in the endometrium throughout the estrous cycle. Immunohistochemical analysis found clear positive staining for TGF-alpha and EGF-R in the luminal and glandular epithelia at proestrus and estrus. Immunoreactivity decreased at the early stage of diestrus. In the mid stage of diestrus, clear staining for TGF-alpha was again found in the glands of the luminal region, and staining for EGF-R was observed in all glands. Very little staining was seen at anestrus for either TGF-alpha or EGF-R. These results suggest that TGF-alpha expressed in the uterus may be involved in regulating growth, differentiation and regression in the endometrial epithelial cells during the estrous cycle in the dog.

Adenomyosis with severe inflammation in the uterine cervix in a dog

A dog with purulent vulval discharge was found to have many cysts containing purulent mucus in the uterine cervix. The uterine horns did not contain any pus. Histological examination revealed a cervical adenomyosis infiltrated by many neutrophils. After an ovariohysterectomy including the whole cervix, the dog recovered well.

The effects of the aromatase inhibitor fadrozole hydrochloride on fetuses and uteri in late pregnant rats

It is well known that progesterone and estrogen are essential hormones for maintaining pregnancy in most mammals. Some specific roles of progesterone for the maintenance of pregnancy have been clarified, but the role of estrogen is not well known. This study examines the effects of the aromatase inhibitor, fadrozole hydrochloride (Fad), on fetuses, uterine physical properties and the mRNA expression of the uterine enzymes that are related to collagen metabolism during late pregnancy in rats. Continuous s.c. infusion with 300 micro g/day Fad from day 14 of pregnancy (day 1=the day of sperm detection) reduced the concentration of plasma estradiol-17beta (E(2)), and did not change that of plasma progesterone, compared with controls. The treatment increased the intrauterine pressure and reduced the size and compliance of the uterine tissue framework. It also caused injuries (hematomata on the extremities) in about one-quarter of fetuses by day 20. The collagen content of the uterine ampullae was not changed by the treatment. Uterine mRNA expressions of matrix metalloproteinase-1 (MMP-1), which degrades collagens, and of lysyl oxidase (LO), which is necessary for the formation of intra- and inter-molecular cross-links of collagen, were examined by quantitative RT-PCR. The treatment with Fad had no effect on the expression of MMP-1 mRNA and increased that of LO mRNA. Daily s.c. injection with 0.2 micro g E(2) restored the changes in uterine physical properties and the mRNA expression of LO caused by the Fad treatment, and prevented fetal injury, indicating that the influences of Fad treatment are due to estrogen deficiency but not to toxicological effects of Fad. These results imply that estrogen deficiency during late pregnancy in rats obstructs development of the uterine tissue framework so as to cause fetal injury. It is possible that an increase in the uterine expression of LO gene may be involved in this obstruction.

Enhancement of prostacyclin synthesis at the beginning of formation of caprine corpora lutea

We examined changes in the levels of prostacyclin (PGI2) synthase mRNA and 6-keto-PGF1alpha, a stable metabolite of PGI2, in the caprine corpus luteum (CL) during its development and subsequent maintenance. We also looked at the effects of a potent GnRH antagonist (GA), which is known to suppress the release of luteinizing hormone (LH), on the PGI2 synthase mRNA level and the 6-keto-PGF1alpha content during CL development. Goats were divided into a control group (n=12) and a GA-treated group (n=6). They were treated with saline or GA (50 microg/kg, s.c.) on days 0 (day of ovulation), 4, and 8 (control only), and the CL were collected from a subset of goats (n=3 for each day) on days 0 (no saline), 4, 8, or 14 (control only). Ribonuclease protection assay was performed to quantify the mRNA in the CL using specific cRNA probes generated by RT-PCR and in vitro transcription. The 6-keto-PGF1alpha content in the CL was measured by radioimmunoassay. The level of PGI2 synthase mRNA and the 6-keto-PGF1alpha content in the CL in the control group decreased from day 0 to day 4 (P<0.01), and did not change thereafter from day 4 to day 14. Levels of PGI2 synthase mRNA and 6-keto-PGF1alpha content in the CL on days 4 and 8 were not affected by treatment with GA. These results suggest that PGI2 synthesis is regulated upward at the beginning of caprine CL formation; this may play a role in initiating CL development. This study also suggests that changes of PGI2 synthesis during CL development are probably not regulated by LH.

Improved conception in timed-artificial insemination using a progesterone-releasing intravaginal device and Ovsynch protocol in postpartum suckled Japanese Black beef cows

The primary objective was to determine the effect of supplemental progesterone, administered via an intravaginal device (CIDR), on conception rates to timed-artificial insemination (timed-AI) in postpartum suckled Japanese Black beef cows treated with the Ovsynch protocol. A secondary objective was to compare the effects of treatments on plasma concentrations of progesterone and estradiol. Cows in the control group (Ovsynch, n=38) received a standard Ovsynch protocol (100 microg GnRH analogue on Day 0, 500 microg PGF2alpha analogue on Day 7, and 100 microg GnRH analogue on Day 9), with AI on Day 10, approximately 20 h after the second GnRH treatment. Cows in the treatment group (Ovsynch+CIDR; n=40) received a standard Ovsynch protocol plus a CIDR for 7 days (starting on Day 0). Plasma progesterone concentrations were determined on Days 0, 1, 7, 9, 10, and 17 and plasma estradiol-17beta concentrations were determined on Days 7, 9, 10, and 17. The odds ratio for likelihood of conception was 3.29 times greater (P=0.02) in the Ovsynch+CIDR group compared to Ovsynch group. The conception rate was greater (P=0.03) in the Ovsynch+CIDR group than in the Ovsynch group (72.5% versus 47.7%). Insertion of a CIDR device significantly increased plasma progesterone concentrations only on Days 1 and 7 (P<0.001 and P=0.05, respectively), but had no significant effect on plasma estradiol-17beta concentrations. Including a CIDR with the Ovsynch protocol significantly improved conception rates in postpartum suckled Japanese Black beef cows.

Studies on the Regulation of Expression of Luteinizing Hormone Receptor in the Ovary and the Mechanism of Follicular Cyst Formation in Ruminants

In the series of studies, changes of expression and regulation of luteinizing hormone (LH) receptor in the ovary of domestic ruminants were examined. Furthermore, mechanisms of formation of follicular cysts in domestic ruminants, caused by stress and so on, were endocrinologically elucidated. Results of the studies provide the following conclusions. (1) The quantity of LH receptor in the bovine antral follicles increases rapidly in the latter stage of its development. (2) The quantity of LH receptor and its mRNA in the bovine and caprine corpus luteum increase during their developments. The increase of the receptor in the caprine luteal development is regulated by LH through the receptor mRNA level. (3) At least, three splice variants of LH receptor mRNA exist in the bovine luteal tissue and the variant receptors are expressed at different cellular sites according to its structure. (4) Intracellular consecutive cysteine residues of LH receptor are palmitoylated and thereby inhibit internalization of the receptor. (5) As a mechanism of the bovine follicular cyst caused by stress, it is suggested that increased secretions of progesterone and cortisol from the adrenal gland exert inhibitory effects on the hypothalamus and follicle, respectively, and subsequently LH and FSH surges are blocked, then finally ovulation is suppressed and the follicle becomes cystic.

Expression of estrogen receptor alpha and beta genes in the mediobasal hypothalamus, pituitary and ovary during the canine estrous cycle

Estrogen receptor alpha (ERalpha) and ERbeta mRNA levels were measured in the mediobasal hypothalamus, the anterior pituitary and the ovary of beagle bitches at various stages of the estrous cycle. With polymerase chain reaction analysis we detected ERbeta gene transcripts in all tissue samples. The levels of hypothalamic and pituitary ERalpha and beta mRNAs increased from mid anestrus to proestrus and declined thereafter. In the ovary, ERalpha mRNA levels increased from proestrus to diestrus and were positively correlated with plasma progesterone levels (r=0.62, P<0.01), whereas ERbeta mRNA levels increased from mid anestrus to proestrus and were positively correlated with plasma estradiol-17beta levels (r=0.73, P<0.001). These results suggest that the rise in hypothalamic and pituitary ERalpha and beta mRNAs is associated with termination of anestrus, and that increases in ovarian ERalpha and beta mRNAs may be involved in initiating development of the follicle or corpora lutea.

Delayed implantation induced by fadrozole hydrochloride in rats

The effect of aromatase inhibitors on the implantation process is not well known. This study examined the anti-implantation action in rats of a nonsteroidal aromatase inhibitor of high specific activity, fadrozole hydrochloride (Fad). Continuous subcutaneous infusion of Fad at 300 microg/day from Day 1 (the day of sperm detection) through Day 7 of pregnancy using a mini-osmotic pump was found to delay the initiation of implantation by 1 or 2 days with no negative effects on embryonic viability. The Fad treatment delayed preimplantation embryo development and zona shedding by embryos. The treatment also delayed the period of maximum sensitivity to a decidualizing stimulus (intraluminal infusion of sesame oil) by 2 days. The results show that continuous treatment with Fad has multiple anti-implantation effects in rats.

Long-term prevention of estrus in the bitch and queen using chlormadinone acetate

Estrus was prevented with weekly oral administration of 2 mg chlormadinone acetate for 2.0 to 9.8 y in bitches and queens. Abnormalities, including mammary or uterine disorders, or both, were noted in 7 out of 14 bitches and 9 out of 24 queens during this long-term treatment.

Changes of messenger RNAs encoding vascular endothelial growth factor and its receptors during the development and maintenance of caprine corpora lutea

The present study was conducted to examine changes of mRNAs encoding vascular endothelial growth factor (VEGF) and its receptors (KDR/Flk-1 and Flt-1), and CD34, which is known to be a specific marker for endothelial cells, during the development and maintenance of the caprine corpora lutea (CL). Effects of a potent GnRH antagonist (GA), which was previously shown to suppress release of luteinizing hormone (LH), on expressions of those mRNAs during the CL development were also investigated. Goats were divided into control (n = 12) and GA-treated groups (n = 6). The goats were treated with saline or GA (50 microg/kg, sc) on days 0 (day of ovulation), 4, and 8 (control only), and CL collected on a subset of goats (n = 3 for each day) on days 0 (no saline), 4, 8, or 14 (control only). Ribonuclease protection assay was performed to quantitate the mRNAs in the CL using specific cRNA probes generated by RT-PCR and in vitro transcription. Level of CD34 mRNA significantly increased from day 0 to 8 (CL development) in the control group (P < 0.05). Long and short forms were detected in the caprine CL by RT-PCR for VEGF mRNA and analyses of their sequences showed that they correspond to mRNAs encoding VEGF(165) and VEGF(121), respectively. Level of VEGF(165) mRNA significantly increased from day 4 to 8 and day 8 to 14 (CL maintenance) in the control group (P < 0.05) while VEGF(121) mRNA did not change during the whole period. Level of KDR/Flk-1 mRNA significantly increased from day 0 to 8 (P < 0.05) while Flt-1 mRNA significantly increased from day 8 to 14 (P < 0.005) in the control group. In the GA-treated group, levels of all of the mRNAs did not alter remarkably as compared with those in the control group. These results suggest that rise of KDR/Flk-1 and VEGF(165) mRNAs during the caprine CL development may be associated with enhanced angiogenesis and that increment of VEGF(165) and Flt-1 mRNAs during the CL maintenance may play nonangiogenic roles. The present study also indicates that the changes of VEGF(165) and KDR/Flk-1 mRNAs during the CL development are probably not regulated by LH.

Inhibition of luteinizing hormone receptor expression during the development of caprine corpora lutea by administration of gonadotropin-releasing hormone antagonist

The present study was conducted to examine effects of a potent GnRH antagonist (GA), which suppresses release of luteinizing hormone (LH), on LH receptor expression during the development of the caprine corpus luteum (CL). Goats were divided into control and GA-treated groups. The goats were treated with saline or GA (50 microg/kg, s.c.) on days 0 (day of ovulation), 4 and 8 (control only), and CL collected on a subset of goats (n = 3 for each day) on days 0 (no saline), 4, 8, or 14 (control only). Ribonuclease protection assay and [(125)I]-hCG binding assay were performed to quantitate mRNA and protein of the LH receptor in the CL, respectively. On day 4, CL weight, levels of LH receptor mRNA and protein in the GA-treated group were similar to those of the control group. By day 8, CL weight and levels of LH receptor mRNA and protein in the GA-treated group were reduced relative to those of the control group (P < 0.05). There was no difference of affinity of the LH receptor between both groups on day 8. These results suggest that the treatment with GA inhibits gene and protein expressions of the LH receptor during the development of CL in the goat, and thus, support an idea that endogenous LH participates in the increase of its own receptor.

Enhancement of aromatase gene expression in the mediobasal hypothalamus during anestrus in the beagle bitch

The relationships among expression of cytochrome p450 aromatase (p450arom) mRNA in the mediobasal hypothalamus (MBH), ovarian aromatase activity, and estrogen secretion were examined throughout the estrous cycle in beagle bitches. Using polymerase chain reaction (PCR) analysis we were able to detect p450arom gene transcripts in the canine MBH. The level of hypothalamic p450arom mRNA increased during the progression of anestrus and declined thereafter. Ovarian p450arom activity, as measured by a (3)H2O assay, were low in anestrus, increased in proestrus, and declined thereafter. Ovarian p450arom activity and plasma estradiol-17beta levels were positively correlated (r=0.77, P<0.05). These results suggest that enhancement of hypothalamic p450arom gene expression is associated with termination of anestrus.

Detection of transforming growth factor-alpha and epidermal growth factor receptor mRNA and immunohistochemical localization of their proteins in the ovine uterus during the early implantation period

Accumulated evidence suggests that growth factors of the epidermal growth factor (EGF) family play an important role in the murine implantation process. In the sheep, however, the uterine distribution of these factors and their receptor, EGF receptor (EGF-R), during implantation is not known. This study examined the presence of mRNA transcripts and immunohistochemical localization for transforming growth factor-alpha (TGF-alpha), the potent EGF-family member, and EGF-R in the ovine uterus during the early implantation period. By reverse transcriptase-polymerase chain reaction and sequencing of the products, the presence of TGF-alpha and EGF-R mRNA transcripts were detected in the endometrium on Days 14, 16 and 20 (Day 0 = day of mating). Immunohistochemical analysis revealed that the luminal and glandular epithelial cells and some stromal cells of the endometrium and the trophectoderm were positive for TGF-alpha and EGF-R on Days 14 and 15. Distinct staining for TGF-alpha was observed in the glandular epithelium of deep endometrial areas and strong immunoreactivity for EGF-R was found in the trophectoderm. On Days 16, 18 and 20, although the staining pattern for TGF-alpha was similar to that on the previous days, the immunoreactivity for EGF-R in the stromal cells increased and that in the gland decreased. A distinct immunoreactivity for EGF-R was found in the trophectoderm throughout the days examined. These results suggest that TGF-alpha expressed in the endometrium and trophectoderm may exert effects locally on these tissues during implantation in sheep. Furthermore, it is speculated that the temporal changes in the uterine EGF-R distribution may be related to the endometrial microvascular development.

Change in concentrations of luteinizing hormone subunit messenger ribonucleic acids in the estrous cycle of beef cattle

Changes in the concentrations of LH subunit messenger ribonucleic acids (mRNAs) and in the LH content of the anterior pituitary of beef cattle were studied during the estrous cycle. Japanese beef cows were classified according to the expected day of the estrous cycle: stage I (early-luteal phase, days 1-4; day 1=day of ovulation), stage II (early-mid-luteal phase, days 5-10), stage III (late-mid-luteal phase, days 11-17) and stage IV (follicular phase, days 18-20), according to the morphology of the ovaries. The anterior pituitaries of the cows were collected and the levels of alpha and LHbeta subunit mRNAs were determined by slot-blot analyses. The LH content of the anterior pituitary was measured by radioimmunoassay. The level of alpha subunit mRNA in the pituitary of cows was highest in stage I and decreased significantly by stage II (P<0.05); thereafter it tended to increase. The level of LHbeta subunit mRNA did not change significantly during the estrous cycle. The LH content of the pituitary of cows was low in stage I and tended to increase by stage II, then to decrease from stage II to III, and to increase significantly from stage III to IV (P<0.05). These results suggest that the highest levels of gene expressions of alpha subunit in the anterior pituitary occur in the early-luteal phase of beef cows, while the LH content is increased most in the follicular phase. The enhanced gene expressions of common alpha subunit in the early-luteal phase could be important in replenishing the bovine anterior pituitary with LH, which is depleted of hormone by the LH surge or the enhanced pulsatile release.

The effect of transforming growth factor-alpha on the progression of decidualization in rats

Although transforming growth factor-alpha (TGF-alpha), one of the epidermal growth factor (EGF) family of growth factors, is expressed in the rat decidual cells, its roles in decidualization remain to be elucidated. This study examined the effect of TGF-alpha on the progression of decidualization and a possibility for involvement of prostaglandins (PGs) in its action. Pseudopregnant rats were ovariectomized and given endometrial trauma on Day 5 (vaginal plug = Day 1) and were daily treated with 2 mg progesterone thereafter. Immunocytochemical localization of EGF receptor was distinctly evident in the decidual, stromal and epithelial cells on Day 7. Continuous infusion of TGF-alpha (500 pg/h) into the uterine lumen from Day 7 significantly increased weights of the uterine horns with deciduomata on Day 9. Although injection on Day 7 of indomethacin, an inhibitor of PGs synthesis, decreased the uterine weight, this effect was overridden by the continuous infusion of this growth factor. These results demonstrated the stimulatory action of TGF-alpha on the progression of decidualization. Further, TGF-alpha increased the secretion of prostaglandin E in cultured decidual and/or stromal cells dose-dependently, suggesting the possibility that PGs mediate the action of this growth factor.

[Carinal resection of bronchogenic carcinoma]

Carinal resection was performed in 10 cases of bronchogenic carcinoma during 12 year-period. The mean age of patients was 58 years, with a range of 42 to 68 years. There were 7 male and 3 female. The tumor was located on the right side in 7 cases, on the left side in 1 case on the carina in 2 cases. The histological examination showed squamous cell carcinoma in 5 cases, adenocarcinoma in 4 cases and adenoid cystic carcinoma in 1 case. The staging revealed T3N2 M0 Stage IIIA in 2 cases, T4N0M0 Stage IIIB in 1 case, T4N1M0 Stage IIIB in 1 case, T4N2M0 Stage IIIB in 5 cases and T4N3M0 Stage IIIB in 1 case. The surgical methods were as follows; sleeve pneumonectomy in 5 cases, wedge carinal resection with pulmonary resection in 3 cases (right sleeve upper lobectomy in 2 cases and right pneumonectomy in 1 case), carinal resection in 2 cases. The site of bronchial anastomosis was overlapped by thymus in 6 cases. The 30-day mortality rate in tracheo-carinal resection was 10% (one patient). Eight patients died and remaining 2 patients are still alive without any evidence of recurrence. 5-year survival rate was 36%. These outcomes were almost equal to those of surgical case in the same stage.

K-ras mutation in sputum of primary lung cancer patients does not always reflect that of cancerous cells

K-ras mutation in sputum was examined using mutant-allele-specific amplification method among 100 primary lung cancer and 15 non-oncological patients. K-ras mutation was detected in 11 out of 59 adenocarcinoma cases (18.6%), 5 out of 32 squamous cell carcinoma cases (15.6%), 2 out of 4 large cell carcinoma cases (50.0%) and 3 out of 15 non-oncological disease cases (20.0%). In the 18 cases of primary lung cancer K-ras mutation was examined in both sputum and the resected specimen of the primary lesion. In 5 cases K-ras mutation in sputum was detected without K-ras mutation in primary lesion. Therefore, these findings suggested that K-ras mutation in sputum may not be directly related to that of the primary lesion.

In situ telomerase activity in pleural effusions: a promising marker for malignancy

Telomerase activity in 16 pleural effusions was studied using an in situ telomerase repeat amplification protocol (TRAP) assay on cytospin preparations. Six of nine cytologically malignant specimens contained telomerase-positive cells (67%), and in two further specimens, suspicious positive cells were seen. Two of four atypical specimens contained telomerase-positive cells, whereas two benign cases were telomerase-negative. No mesothelial cells showed telomerase reactivity. Thus, telomerase activity was specific for malignancy and it was always found only in malignant cells. The results suggest that telomerase activity measured with this in situ method can be a valuable complement in the assessment of malignancy in pleural effusions.

Roles of pulsatile release of LH in the development and maintenance of corpus luteum function in the goat

The roles of the pulsatile release of LH in the functional development and maintenance of the corpus luteum (CL) during the estrus cycle in the goat were examined using a potent GnRH antagonist. In Experiment 1, to assess the inhibitory effects of the GnRH antagonist on the release of LH during the estrus cycle, 9 goats were divided into 3 groups. Goats in Group I received only saline on Days 0 (day of ovulation), 5, 10 and 15. Goats in Group II received the GnRH antagonist (50 microg/kg, s.c.) on the days mentioned for Group I to inhibit endogenous LH during the periods of luteal development and maintenance. Goats in Group III received saline on Days 0 and 5 and then the GnRH antagonist on Days 10 and 15 to inhibit LH during the period of luteal maintenance. Serial blood sampling took place on Days 1, 3, 5, 8, 13 and 18 to characterize the LH pulses. The LH pulses were observed throughout the estrus cycle in Group I but were completely abolished in Group II. In Group III, the pulsatile release of LH was observed from Day 1 to 8, but the LH pulses were completely abolished on Days 13 and 18. In Experiment 2, 16 goats were divided into the same 3 groups as in Experiment 1 to examine the effects of the GnRH antagonist on the luteal function. The concentration of progesterone in the plasma in Group I increased after ovulation, reached a maximum level around Day 12, and subsequently returned to the basal level on Day 17. The concentrations of progesterone in Group II rose after ovulation, but reached a plateau around Day 6 and maintained the level up to Day 9, then rapidly decreased from Day 9 to 10 to the basal level. The concentrations of progesterone in Group II were lower on Days 7 to 15 than those in Group I (P<0.01). The concentrations of progesterone in Group III increased after ovulation, reached a maximum level around Day 8, then dropped from Day 10 to 13 to the basal level. The concentrations of progesterone in Group III on Days 11 to 15 were lower than those in Group I (P<0.05 on Day 11, P<0.01 on Days 12 to 15). These results demonstrate that endogenous LH is essential for normal development and maintenance of the CL function during the estrus cycle in the goat. Further, this study suggests that while the functional maintenance of the caprine CL depends entirely on LH support, such functional dependence during early CL development is only partial.

Luteinizing hormone receptors in the bovine corpus luteum during the oestrous cycle and pregnancy

The concentration and affinity of luteinizing hormone (LH) receptors in bovine luteal tissues during the oestrous cycle and pregnancy were investigated by Scatchard analysis of the binding of 125I-labeled human chorionic gonadotropin. Corpora lutea (CL) were classified into five stages of the oestrous cycle and three stages of pregnancy. The concentration of LH receptors sharply increased from the early I stage of the oestrous cycle (Days 2-3; 3.09 fmol mg(-1) protein) to the early II stage (Days 5-6; 9.44 fmol mg(-1) protein) and then remained constant until the late luteal stage (Days 15-17; 8.14-9.56 fmol mg(-1) protein). The LH receptors could not be analysed in the regressed luteal tissue due to the small amounts of binding. There was no significant difference in the concentrations of LH receptors (5.63-9.64 fmol mg(-1) protein) among the three stages of pregnancy. Moreover, the concentrations of the receptors in the CL of pregnancy were comparable to those in the mid-cycle CL. The binding affinity did not change significantly during the oestrous cycle and pregnancy. Based on these results, it is assumed that the luteal function during the entire period of pregnancy might be regulated, at least in part, by LH, which is mediated via its specific receptors, and that the luteal function during pregnancy seems not to be regulated by changes in the binding capacity and affinity of LH receptors. To understand the physiological roles of LH in regulating luteal function in pregnant cows, further studies are required.

Epidermal growth factor (EGF) in the goat uterus: immunohistochemical localization of EGF and EGF receptor and effect of EGF on uterine activity in vivo

This study examined the distribution of immunoreactive epidermal growth factor (EGF) and EGF receptor (EGF-R) in the uterus and the effects of EGF on uterine activity in goats. Immunohistochemistry of EGF and EGF-R in the uteri showed distinct staining in the luminal and glandular epithelium and slight to moderate staining in the stromal and myometrial cells. To examine possible roles of the EGF system in the regulation of uterine activity, pressure changes in the intrauterine balloon were determined after intraluminal infusion of EGF into the uterine horn. Either at estrus or diestrus (9 to 14 days after the first day of estrus), treatment with 1 or 5 microg of EGF gradually reduced uterine activity, whereas infusion of the vehicle alone had no effect. The maximum reduction in uterine activity was seen 4 h after the treatment with 1 microg of EGF (40% to 45% reduction in the area surrounded by the contraction curve and its baseline), and the activity slowly returned thereafter. These results suggest that EGF in the uterus may play a role in regulating uterine activity in goats.

[Bronchofiberscopy]

New diagnostic modalities have been used in conjunction with endoscopy for early detection of lung cancer. Videoendoscope is routinely used instead of fiberoptic bronchoscope. Fluorescence diagnosis has been proved to be useful in detecting subtle lesions which might be invisible by conventional endoscopy in central airway. Also, a number of small peripheral lesions has increased by the helical CT. CT guided transbronchial lung as well as needle cytology are indicated for definitive diagnosis of such lesions. Endobronchial Ultrasonography is employed to evaluate the depth of cancer invasion of the bronchus and lymph node swelling around the bronchus. It should be helpful in staging of lung cancer and selecting therapy.

[Molecular biological diagnosis]

Biological behavior of lung cancer was evaluated by basic study. Malignancy Associated Change is the concept that the nuclear features of normal cells in the vicinity of cancer show subtle morphological difference from those of healthy individuals. The difference was recognized by high resolution cytometry and the expression of MAC cells was correlated with the degree of abnormality of chest diseases. Comparative genomic hybridization and fluorescence in situ hybridization were performed to investigate genetic abnormality of. Multiple genetic abnormalities and chromosomal instability showed poor prognosis. Two dimensional electrophoresis was employed to detect the expression of the specific protein of lung cancer. TAO2 was proved to be specific to well differentiated adenocarcinoma. Also, metabolic analysis will be employed for cell analysis.

Correlation between morphology and telomerase activity in cells from exfoliative lung cytologic specimens

BACKGROUND

Telomerase is a ribonucleoprotein that compensates for the erosion of telomeres (chromosomal termini). Telomerase activity is detected in more than 85% of cancerous lesions and is therefore considered a novel marker of cancer. The authors compared cytologic morphology and telomerase activity at the cellular level to obtain further insight into their association.

METHODS

The authors used bronchial washing and brushing materials obtained from 18 patients with lung carcinomas (6 squamous cell, 8 adenocarcinoma, 2 large cell, 1 small cell, and 1 metastasis from colon carcinoma) and 20 patients with nonmalignant disease. An in situ telomeric repeat amplification protocol (TRAP) assay was performed, and routine Papanicolaou-stained slides using the same sample were assessed.

RESULTS

Nuclear fluorescent signals at the nuclear area, corresponding to telomerase activity, shown by the in situ TRAP assay were only detected in samples containing morphologically malignant cells. No nuclear fluorescence was seen in the keratinizing component of well-differentiated squamous cell carcinoma. Nuclear staining was not seen in metaplastic or basal hyperplastic cells. Cytoplasmic fluorescence was only found in macrophages and polymorphonuclear leukocytes.

CONCLUSIONS

Nuclear fluorescence corresponding to telomerase activity was not demonstrated in metaplastic or basal hyperplastic cells, thus indicating that detection of telomerase activity is closely associated with the presence of malignant cells, but not premalignant lesions, in lung carcinoma patients. Moreover, in some samples with cancer, cells failed to show telomerase activity, suggesting the limitation of this method for the detection of malignant cells in certain lung carcinoma patients.

Tumor necrosis factor-alpha and its receptor in bovine corpus luteum throughout the estrous cycle

The objective of this study was to investigate tumor necrosis factor alpha (TNF-alpha) expression, the presence of functional TNF-alpha receptors, and expression of TNF receptor type I (TNF-RI) mRNA in the bovine corpus luteum (CL) during different stages of the estrous cycle. Reverse transcription (RT)-polymerase chain reaction (PCR) showed no difference in TNF-alpha mRNA expression during the estrous cycle. Concentrations of TNF-alpha in the CL tissue increased significantly from the mid to the late luteal stage and decreased thereafter (P < 0.05). An RT-PCR analysis showed higher levels of TNF-RI mRNA in CL of Days 3-7 than of other stages (P < 0.05). (125)I-TNF-alpha binding to the membranes of bovine CL was maximal after incubation at 38 degrees C for 48 h. The binding was much greater for TNF-alpha than for related peptides. A Scatchard analysis revealed the presence of a high-affinity binding site in the CL membranes collected at each phase of the estrous cycle (dissociation constant: 3.60 +/- 0.58-5.79 +/- 0.19 nM). In contrast to TNF-RI mRNA expression, the levels of receptor protein were similar at each stage of the estrous cycle. When cultured cells of all luteal stages were exposed to TNF-alpha (1-100 ng/ml), TNF-alpha stimulated prostaglandin F(2alpha) and prostaglandin E(2) secretion by the cells in a dose-dependent fashion (P < 0.01), especially during the early luteal phase, although it did not affect progesterone secretion. These results indicate the local production of TNF-alpha and the presence of functional TNF-RI in bovine CL throughout the estrous cycle, and suggest that TNF-alpha plays some roles in regulating bovine CL function throughout the estrous cycle.

Increased LH pulse frequency and estrogen secretion associated with termination of anestrus followed by enhancement of uterine estrogen receptor gene expression in the beagle bitch

The relationships among pulsatile LH secretion pattern, estrogen secretion, and expression of the uterine estrogen receptor gene were examined throughout the estrous cycle in beagle bitches. In Experiment 1, blood samples were collected from 30 bitches every 10 min for 8 h from a cephalic vein during different phases of the estrous cycle. An increase in the mean plasma levels of LH occurred from mid to late anestrus (P < 0.01). The LH pulse frequency increased (P < 0.01) from late anestrus to proestrus, and was strongly correlated (r = 0.96, P < 0.001) with the mean plasma level of estradiol-17 beta (E2). In Experiment 2, middle uterine samples, including the myometrium and endometrium, from 18 bitches were taken at 6 stages of the estrous cycle. The total number of estrogen receptors and nuclear estrogen receptor and its mRNA levels in the uterus also increased (P < 0.01) from late anestrus to proestrus. Mean plasma E2 level and the number of uterine estrogen receptor were positively correlated (r = 0.81, P < 0.05). In Experiment 3, nine bitches were ovariectomized in mid anestrus. Two weeks later they received a single injection of 10 or 50 micrograms/kg, i.m., estradiol benzoate. The number of uterine estrogen receptor and their mRNA levels for ovariectomized bitches were low, but increased (P < 0.05) after treatment with a low dose of estradiol benzoate. These results suggest that increases in LH pulse frequency and estrogen secretion are associated with termination of anestrus and that subsequent enhancement of uterine estrogen receptor expression may be up-regulated by estradiol.

Oxytocin gene expression and action in goat testis

Gene expression, immunohistochemical localization, binding and effects of oxytocin (OT) on androgen production in the testis of adult goats were studied. Using polymerase chain reaction (PCR) analysis we were able to detect OT gene transcripts in the goat testis. Immunohistochemistry revealed that both OT and neurophysin epitopes were expressed together in the intratubular regions, especially in the Sertoli cells, suggesting the production of OT in these cells. However, enzyme immunoassay found no difference in OT concentration between testicular arterial and venous plasma. Saturable, specific [3H]-OT binding sites were present in membrane fractions of the goat testis. Scatchard analysis indicated an apparent affinity of 42 +/- 7 L/nmol and binding capacity of 24 +/- 4 fmol OT bound/mg DNA. In vitro treatment of goat testes for 6 h with 100 nM OT led to a 3.5-fold increase (P < 0.001) in 5 alpha-dihydrotestosterone (DHT) production in spite of the induced decrease in testosterone, suggesting that OT not only affects testosterone production but also modulates its conversion to DHT. These results indicate that the goat testis produces OT, which may be involved in the local control of androgen biosynthesis.

The relationship between p21/waf1 expression patterns and cell proliferation during the tumorigenesis of the bronchus

Each developmental stage in the process towards bronchial squamous cell carcinoma (normal epithelium, squamous metaplasia and early stage squamous cell carcinoma including in situ carcinoma) was examined for p21/waf1 protein expression and cell proliferation using MIB1. P21/waf1 immunoreactivity was classified into four patterns: predominantly cytoplasmic staining, exclusively nuclear staining, both nuclear and cytoplasmic staining and negative. The cases with predominantly cytoplasmic staining showed suppression of cell proliferation. Most cases with either negative or exclusively nuclear staining revealed high cell proliferation. The simultaneous evaluation of p21/waf1 and cell proliferation is valuable for clinical determination of the high risk for malignant transformation.

The effects of heparin-binding epidermal growth factor-like growth factor on preimplantation-embryo development and implantation in the rat

This study examined the effects of heparin-binding epidermal growth factor-like growth factor (HB-EGF) on preimplantation-embryo development and initiation of implantation in the rat. In vitro studies showed that HB-EGF improved the development of 8-cell embryos to the blastocyst stage in a concentration-dependent manner, and the growth factor had no effect on the cell number of the blastocyst developed. Intraluminal injection of an anti-HB-EGF antiserum into the uterine horns at 0600 h on day 5 of pregnancy decreased the number of implantation sites (blue dye reaction) at 0200 h on day 6. Intraluminal injection of 20 microl of HB-EGF solution (10 or 100 ng/ml) into each uterine horn induced implantation in about half of the ovariectomized progesterone-treated delayed implanting rats, and the number of implantation sites per rat increased dose-dependently. These results suggest that HB-EGF is involved in the preimplantation-embryo development and initiation of implantation in the rat.

Cytologic features based on the expression of E-cadherin and catenins in lung adenocarcinoma

OBJECTIVE

To investigate the relationship between E-cadherin-associated cell-to-cell adhesion and cytologic features in preoperative cytologic lung adenocarcinoma specimens.

STUDY DESIGN

Evaluation of the relationship between cell-to-cell adhesion, formation of cellular clusters and frequency of single cells in 31 cases of primary lung adenocarcinoma, collected by brush and needle cytology preoperatively.

RESULTS

Most cases with remarkable overlapping of cells in compact cellular clusters and a few solitary cells maintained cell-to-cell adhesion. Cellular clusters that had a slight tendency to overlap, a small cell-to-cell adhesion area and a high frequency of solitary cells tended to lack E-cadherin-associated cell-to-cell adhesion.

CONCLUSION

Formation of cellular clusters and the appearance of solitary cancer cells are closely related to E-cadherin-associated cell-to-cell adhesion. Therefore, it is highly likely that cytologic features may indicate malignant behavior, such as local invasion and lymph node metastasis, in primary lung adenocarcinoma.

Peripheral non-small cell lung cancers 2.0 cm or less in diameter: proposed criteria for limited pulmonary resection based upon clinicopathological presentation

Clinical features of peripheral non-small cell lung cancer 2.0 cm or less were retrospectively analyzed. Nodal status and prognosis in relation to tumor diameter and histologic type were investigated in 171 consecutive patients with peripheral clinical T1N0M0 non-small cell lung carcinomas 2 cm or less in diameter and who had undergone surgical resection between 1976 and 1997. Of the 171 patients, 136 had adenocarcinoma, 27 had squamous cell carcinoma, four had large cell carcinoma, three had carcinoid and one had adeno-squamous carcinoma. There was no statistically significant difference in the incidence of stage I cases between adenocarcinoma and squamous cell carcinoma. Lymph node involvement was recognized in 30 (17.5%) patients: ten (5.8%) at N1 nodes and 20 (11.7%) at N2 nodes. Lymph node metastasis was significantly more common in tumors 1.5-2.0 cm in diameter (22%) than in those 1.5 cm or less in diameter (14.0%, P = 0.0490). There was no lymph node metastasis in tumors 1.0 cm or less in diameter. The 5-year survival rates cases with or without lymph node involvement were 63.3 and 75.3%, respectively, showing significant difference (P = 0.0338). The result of the present study suggested that systematic mediastinal and hilar lymph node dissection is necessary even for cases with tumor diameter less than 2 cm. However, if the tumor is within 1.0 cm in diameter, mediastinal lymph node dissection might be dispensable; therefore, these cases are good candidates for video-assisted lobectomy.

Coordinated expression of splice variants for luteinizing hormone receptor messenger RNA during the development of bovine corpora lutea

We characterized splice variants for LH receptor mRNA in the bovine corpus luteum and examined the levels of expression of all the splice variants during the development of corpus luteum. Total RNA was extracted from bovine corpora lutea, and reverse transcriptase-polymerase chain reaction (RT-PCR) was performed to amplify a part of the extracellular and transmembrane domains. As a result, four distinct bands were observed on analyses with polyacrylamide gel electrophoresis, and sequencing of the products revealed that the largest form (519 bp) was the full-length A form and that the three shorter forms (438, 253, and 172 bp) were its splicing variants. Splicing patterns of the 438-, 253-, and 172-bp forms are identical to the F, B, and G forms, respectively, found in the ovine ovary. In order to examine the level of expression of all these splice variants simultaneously, semiquantitative RT-PCR was set up and performed. The relative intensities for all four forms of LH receptor mRNA significantly increased (P < 0.05) from Stage I (Days 1-4; Day 1 = day of ovulation) to IIS (Days 5-10, CL weight < 4 g), and from Stage IIS to IIL (Days 5-10, CL weight > or = 4 g). The intensities of all forms for LH receptor mRNA decreased slightly, but not significantly, from Stage IIL to III (Days 11-17). The ratios of the levels for all the forms did not change significantly during the development of the corpus luteum. Determination of the steady-state levels of LH receptor mRNA by Northern blotting showed similar changes during the development of the corpus luteum to changes of the splice variants examined by the semiquantitative RT-PCR. These results suggest that at least three splicing variants of LH receptor mRNA (i.e., F, B, and G forms) exist in the bovine corpus luteum and that the levels of all the forms of LH receptor mRNA increased in a coordinated manner during the development of bovine corpus luteum.

Induction of luteinizing hormone surge by pulsatile administration of gonadotropin-releasing hormone analogue in cows with follicular cysts

LH release in response to pulsatile administration of small amounts of GnRH analogue in cows with follicular cysts was examined. The pulsatile administration of GnRH analogue induced a LH-surge like peak over 10 hr in both normal cows and cows with follicular cysts. The mean peak value of LH in follicular cystic cows did not differ significantly from that of normal cows. All the cows with cysts resumed normal estrous cycles with ovulations within 3 weeks of this treatment. These results suggest that the function of the anterior pituitary for LH release in response to GnRH analogue is not abnormal in cows with follicular cysts, and that cystic cows recover to normal conditions after the pulsatile administration of GnRH analogue.

Role of palmitoylation of conserved cysteine residues of luteinizing hormone/human choriogonadotropin receptors in receptor down-regulation

The conserved cysteine residues 621 and 622 of luteinizing hormone/human chorionic gonadotropin receptors were converted to serine (C621S, C622S, C621/622S) and glycine residues (C621/C622G) by site directed mutagenesis. The wild type and mutant receptor cDNAs were cloned into the mammalian expression vector (PCMV4) and human embryonic kidney cells (293 cells) were transiently transfected with these constructs. Equilibrium binding studies with [(125)I]hCG (human chorionic gonadotropin) showed that the mutant and wild type receptors expressed on the cell surface exhibited similar K(d). The effect of mutation of the conserved cysteine residues on the ability of the receptors to undergo ligand-induced down-regulation was then tested. In vitro exposure of cells expressing the wild type receptor to a saturating concentration of human chorionic gonadotropin (100 ng/ml) for 24 h resulted in modest down-regulation of receptors. The palmitoylation deficient mutants, C621S, C622S, C621/622S and C621/622G, showed increased down-regulation compared with the wild type receptor. The extent of down-regulation of the mutant receptors correlated with increased internalization of the receptor. Additionally, the G protein coupling efficiency of the palmitoylation deficient mutants was not different from the wild type since the EC(50)s for cyclic AMP (cAMP) production were identical in both groups. These studies demonstrate that palmitoylation deficient mutants are more prone to ligand-induced receptor down-regulation. Furthermore, abrogation of palmitoylation by mutagenesis showed no effect on the efficiency of the palmitoylation deficient mutants to couple to Gs protein.

Post-translational processing in the Golgi plays a critical role in the trafficking of the luteinizing hormone/human chorionic gonadotropin receptor to the cell surface

Point mutations in the luteinizing hormone/human chorionic gonadotropin (LH/hCG) receptor have been shown to cause constitutive activation which results in precocious puberty in affected males. We introduced one of these mutations, Asp-556 --> Gly, into the rat LH/hCG receptor and demonstrated that the mutant receptor constitutively activated adenylate cyclase in transfected 293 T cells. The cell surface expression of the mutant receptor was lower than that of the wild type receptor. Pulse-chase studies showed that the 73-kDa precursor of both the mutant and wild type receptors was synthesized at comparable efficiencies. However, post-translational processing of the mutant receptor to the mature 92-kDa form, which has N-linked complex type oligosaccharide chains, was impaired. Sensitivity of the mutant receptor to peptide-N-glycanase F and endoglycosidase H, and insensitivity to sialidase indicated that the 73-kDa species represents the high mannose form that has not yet been trafficked through the medial and trans Golgi. Additionally, although the wild type receptor was palmitoylated, the mutant receptor was not. Although the high mannose 73-kDa species is capable of binding LH/hCG, our results show that post-translational processing in the Golgi is required for the mature 92-kDa receptor to reach the cell surface.

Evaluation of a new solution containing trehalose for twenty-hour canine lung preservation

We examined the efficacy of two new preservation solutions containing trehalose--an extracellular type (ET-K) of solution and an intracellular type (IT-K) of solution--in relation to that of Euro-Collins (EC) solution in 20-h canine lung preservation. Canine lungs were flushed with one of the three solutions (n = 5 for each solution) after pretreatment with PGE1 (20 micrograms/kg) and were stored for 20 h at 4 degrees C. The left lungs were transplanted and evaluated to 6 h post transplant. In the ET-K group, the arterial oxygen tension after reperfusion was significantly higher than in the IT-K and EC groups. The pulmonary vascular resistance, wet/dry weight ratio, and histological evaluation of each transplanted lung in the ET-K group were also better than in the IT-K and EC groups. This indicates that ET-K solution is useful for 20-h preservation of canine lung grafts.

Changes in plasma concentrations of gonadotropins and steroid hormones during the formation of bovine follicular cysts induced by the administration of ACTH

Bovine follicular cysts were induced by treatments with ACTH (3 mg, im) daily for 14 days beginning in the late luteal phase. Cortisol concentrations in plasma significantly increased after ACTH treatments. During the formation of follicular cysts induced by the injections of ACTH, mean plasma concentrations of progesterone were significantly higher than those in the untreated preovulatory period, while mean plasma concentrations of estradiol-17 beta were significantly lower. During the treatment period, mean plasma concentrations of LH and FSH remained low, and the preovulatory surges of LH and FSH did not occur. Suppressed concentrations of LH and FSH might be caused by the increases in secretions of cortisol and progesterone, and by the decrease in secretion of estradiol-17 beta.

Identification of constitutively activating mutation of the luteinising hormone receptor in a family with male limited gonadotrophin independent precocious puberty (testotoxicosis)

A family of male limited gonadotrophin independent precocious puberty was examined for activating mutation of the LH receptor. A transition of A to G in nucleotide 1733 of the human LH receptor gene was identified in all affected males and in an unaffected carrier female. The mutation was shown by identifying a new restriction site created by the mutation. This mutation appears to be a common feature of the disorder, as it has been reported previously in unrelated families. Therefore, the presence of this new restriction site can serve as a diagnostic tool in males at risk before the onset of symptoms, as well as identifying carrier females.

Palmitoylation of luteinizing hormone/human choriogonadotropin receptors in transfected cells. Abolition of palmitoylation by mutation of Cys-621 and Cys-622 residues in the cytoplasmic tail increases ligand-induced internalization of the receptor

We have examined whether the two cysteine residues (621 and 622) of the carboxyl-terminal cytoplasmic domain of the rat luteinizing hormone (LH/hCG) receptor are potential sites for palmitoylation. The full-length LH/hCG receptor cDNA was cloned into an expression vector (hCGR-pCMV4). A human embryonic kidney cell line expressing large T antigen (293T cells) was transiently transfected with hCGR-pCMV4 by the calcium phosphate precipitation technique. The functional expression of the receptor was confirmed by 35S-labeled cysteine incorporation into the receptor as well as by 125I-human chorionic gonadotropin (hCG) binding. The transfected cells were then labeled with [3H]palmitic acid, and the labeled receptors purified on hCG-Affi-Gel matrix and subjected to SDS-polyacrylamide gel electrophoresis and autoradiography. The hCGR-pCMV4-transfected cells incorporated [3H]palmitic acid into a 92-kDa band corresponding to the mature form of the LH/hCG receptor; this band was absent in cells transfected with vector alone. Site-directed mutagenesis of either cysteine 621 or 622 to serine residue was partially inhibitory, whereas mutation of both cysteine residues (621 and 622) completely abolished palmitoylation. Scatchard analyses revealed that the mutant and wild type receptors have similar affinities for 125I-hCG. The biological function of palmitoylation was then examined in the transfected cells. The results showed that although the intracellular trafficking of the receptor and the ability to stimulate cyclic AMP production were unaffected, the rate of ligand-induced internalization of the receptor was higher in palmitoylation-deficient mutants compared to the wild type receptors. The first order rate constants of internalization of the mutant receptors were over 2-fold higher than the wild type. Intracellular degradation of the receptor-bound ligand was also higher in the mutants. These studies suggest that the native LH/hCG receptor is palmitoylated at cysteine residues 621 and 622, creating a membrane-anchoring site at the putative cytoplasmic domain. This palmitic acid-mediated anchoring decreases the ligand-induced receptor internalization thereby prolonging the retention of the ligand-bound receptor on the cell surface.