Protein kinase C stimulates release of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 by human decidual cells.

OBJECTIVE: Increased concentrations of amniotic fluid matrix metalloproteinase (MMP)-9 and tissue inhibitor of metalloproteinase (TIMP)-1 have been observed in the context of premature rupture of membranes (PROM) and microbial invasion of the amniotic cavity. However, the source of the stimuli that contribute to the accumulation of these proteins in amniotic fluid remains to be identified. The present study was conducted to investigate MMP-2, MMP-9 and TIMP-1 secretion by decidual cells in response to activated protein kinase C (PKC). METHODS: Decidual cells were isolated from term placentae, grown to confluence and incubated with control media or 10(-11) to 10(-8) mol/l concentrations of phorbol 12-myristate 13-acetate (PMA). Concentrations of MMP-2, MMP-9 and TIMP-1 in the culture supernatant were determined using sensitive and specific immunoassays. Substrate zymography was conducted to confirm MMP-9 assays. RESULTS: PMA induced a concentration-dependent stimulation of release of MMP-9 (control vs. PMA l0(-9) and 10(-8) mol/l; p < 0.01) and TIMP-1 (control vs. PMA 10(-9) and 10(-8) mol/l; p < 0.001), but not MMP-2. A direct positive correlation was observed between MMP-9 and TIMP-1 release (r = 0.645; p < 0.001). Substrate zymography confirmed increased release of MMP-9 in response to PMA (control vs. PMA 10(-8) and PMA 10(-7) mol/l; p < 0.01). CONCLUSIONS: Activation of PKC within the decidua will result in enhanced MMP-9 release, which upon activation could contribute to degradation of matrices within fetal membranes leading to PROM.

Chronic alcohol exposure and lactation: extended observations.

Previous results from our laboratory have indicated that chronic (8 days) alcohol administration inhibits suckling-induced prolactin (PRL) release in response to 30 min of suckling. In addition, chronic alcohol administration to dams resulted in growth retardation of their litters. The present study was done to examine how an extended period of suckling (120 min) affected suckling-induced PRL release after chronic alcohol exposure. In addition, it was also examined whether the growth retardation observed during alcohol exposure persisted after alcohol infusions were discontinued. Dams were implanted with an atrial catheter on day 3 of lactation and saline or alcohol (1.0- or 2.0-g/kg BW) was administered daily for 8 days (lactation days 5 through 12). Following administration of the initial alcohol dose, the infusion was continued at rates required to maintain blood alcohol levels (BALs) for 4 h each day. Testing took place on day 12. As previously reported, suckling-induced PRL release was inhibited in dams receiving 2.0-g/kg alcohol after 30 min of suckling. However, after 120 min of suckling, PRL release in these dams was much higher than in either control or 1.0-g/kg alcohol dams. In addition, while the body weights of litters of dams administered 2.0-g/kg alcohol were reduced compared to litters of dams in the other two groups on days 8-16, their body weights rebounded and were not different from the other litters on days 18 or 20.

Alcohol inhibits suckling-induced oxytocin release in the lactating rat.

Oxytocin release in response to suckling was examined in primiparous lactating rats following alcohol administration. Lactating rats, with litters adjusted to eight pups on day 2, were implanted with an atrial catheter between days 6 to 8 of lactation. Four days later, alcohol in doses 0.0, 1.0, or 2.0 g/kg BW was infused, and blood alcohol levels achieved following infusion of initial doses were maintained for 4 h. On the day of alcohol infusion, pups were separated from the dams at 8:00 A.M. Following completion of alcohol infusion, a baseline blood sample was obtained, pups were returned to the dams, and additional samples were obtained 5, 10, 30, and 60 min after suckling started. Oxytocin levels in plasma were determined by radioimmunoassay. Suckling latencies and milk consumption during the 60 min of suckling were determined. Alcohol administration inhibited suckling-induced oxytocin release across all time points. Suckling latencies among groups were comparable. Milk consumption by pups during the 60 min of suckling was lower for the alcohol administered groups. The data from the present study demonstrate that acute alcohol administration to lactating rats inhibits suckling-induced oxytocin release resulting in reduction of milk secretion.

Ethanol and lactation: effects of milk lipids and serum constituents.

To determine how chronic alcohol administration during lactation affects milk composition and the nutritional status of the dam, EtOH (3 g/kg) as a 20% solution was administered by intubation to Sprague-Dawley rats from days 2 through 15 of lactation. Control dams were pair fed to account for the reduction in food intake observed in the alcohol group, while another control group maintained ad lib food intake. Dams and their litters were weighed daily throughout the study. On day 16, dams were sacrificed and samples taken for further analysis. Blood alcohol levels as well as serum levels of calcium, cholesterol, glucose, iron, lipids, phosphorous, and triglycerides were measured. Liver lipid levels and the total composition and fatty acid profile of the phospholipids in milk were also measured. Results indicate that EtOH administration and pair feeding reduced dam body weight, but not litter growth. Serum iron levels was increased in both EtOH-exposed and pair-fed controls, whereas serum cholesterol was elevated only in EtOH-exposed dams. Finally, of the phospholipids in milk, only one, phosphatidylserine, was slightly but significantly increased by EtOH. If and how these changes impact the development of the offspring remain to be studied.

Alcohol and the hormonal control of lactation.

All mammals produce milk to nourish their young. Milk production (i.e., lactation), which occurs in the mammary glands, is regulated by several hormones, most prominently prolactin and oxytocin. Studies in both humans and laboratory animals have demonstrated that maternal alcohol consumption before and during lactation can interfere with the functions of both of those hormones. Moreover, animal studies found that maternal alcohol consumption during pregnancy and even earlier in the mother's life can impair mammary gland development. Maternal alcohol consumption during pregnancy and lactation also can alter the milk's nutrient composition and result in suckling deficits of the offspring. Alcohol (and possibly its breakdown products) can pass from the maternal circulation into the breast milk. The effects of these substances on the infant, however, are still unknown.

Sulpiride-induced increases in serum prolactin levels in female rats exposed prenatally to alcohol.

We examined the impact of prenatal alcohol exposure on serum prolactin levels and on the ability of the D2 dopamine antagonist sulpiride to stimulate prolactin release in Long-Evans rats. Pregnant rats were intubated with alcohol (0, 3, or 5 g/kg/day) from gestational day 8 (GD8) to GD20. Adult female offspring were screened for estrous cycle stage. At diestrus, the rats were challenged with a single dose of sulpiride (0, 10, or 40 micrograms/kg) and trunk blood was collected 20 min later. After prenatal exposure to either dose of alcohol, mean basal serum levels of prolactin were about 65% less than the 0 g/kg group, and the 35-40% mean differences from an untreated control group were not significant. Sulpiride produced dramatic dose-dependent increases in serum prolactin levels in all prenatal treatment groups. Across all doses of sulpiride, the group given the higher dose of prenatal alcohol (5 g/kg/day) had significantly lower serum prolactin levels than all other groups. There was no significant interaction between prenatal treatment and sulpiride dose. Neither prenatal alcohol exposure nor sulpiride injections had significant effects on serum corticosterone levels in this study. Although the current results are unclear regarding a baseline decrease in prolactin levels after prenatal alcohol exposure, the overall results suggest that prenatal alcohol exposure decreases prolactin levels but there is no evidence that it does so by altering dopaminergic tone in hypothalamus of female rats.

Evaluation of lactational parameters after alcohol administration for four days during early or midlactation in the rat.

This study was conducted to examine the effects of alcohol administered for 4 days during early lactational (days 5 to 8; experiment I) or midlactational (days 9 to 12; experiment II) stage in the rat on various lactational parameters. Litter size was adjusted to eight on day 2, and dams were implanted with an atrial catheter on day 3 (experiment I) or day 7 (experiment II). From days 5 to 8 in experiment I and days 9 to 12 in experiment II, dams were infused with saline (control rats) or alcohol in saline solutions (1.0 and 2.0 g/kg body weight; experimental groups). Blood alcohol levels (BALs) achieved after infusion of the initial doses were maintained for 4 hr daily by continuing infusion. To control for the reduced food intake in the high dose alcohol group, one control group and the group given 1.0 g/kg of body weight alcohol were pair-fed to the 2.0 g/kg body weight alcohol group. On day 8 (experiment I) or day 12 (experiment II), pups were separated from the dam at 0800 hr, and an extension was attached to the catheter. Alcohol or saline was infused, and the BALs achieved after infusion of initial doses were maintained for 4 hr. After removal of a baseline blood sample, pups were returned to dams, and additional blood samples were taken for prolactin measurement 10, 30, 60, and 120 min after suckling started. Suckling latency and milk consumed during the 120 min of suckling were measured. Litters were weighed every other day from days 2 to 21. In both studies, suckling-induced prolactin was inhibited by alcohol. Milk consumed by the pups during the 2-hr period was lower for alcohol groups, compared with control. The suckling latencies were comparable among groups. Litter weights showed no alcohol dose effect. In summary, based on the results from our previous and present studies, we conclude the following: alcohol administered for 1, 4, or 8 days inhibited suckling-induced prolactin release in lactating rats. During a 2-hr test period after alcohol administration, milk consumed by pups was not adversely affected after alcohol administration for 1 day. Whereas, 4 or 8 days of administration had a significant effect. The adverse effect of alcohol on litter growth, however, was evident only after 8 days of alcohol administration. Thus, the detrimental effects of alcohol on different lactational parameters seem to be correlated to the duration of alcohol administration to dams during lactation.

Midcycle increase of prolactin seen in normal women is absent in subjects with unexplained infertility.

OBJECTIVE: To compare the bioactive and immunoactive PRL in normal and unexplained infertility subjects. DESIGN: Prospective study. SETTING: Department of Obstetrics and Gynecology, Wayne State University and The University of Michigan. PATIENT(S): Twelve normal, fertile women compared with 12 patients with unexplained infertility. INTERVENTION(S): Serum samples were obtained across the menstrual cycle and for each subject, 5 pools were prepared by combining serum aliquots from the early follicular, late follicular, midcycle, and midluteal and late luteal phases of the cycle. MAIN OUTCOME MEASURE(S): Niobium lymphoma cell bioassay and an immunoradiometric assay were used to quantitate PRL. RESULT(S): A midcycle increase in PRL was seen in controls by both assays and these levels were greater compared with other cycle stages. Comparison of midcycle PRL between groups showed differences only between bioactive PRL (34.2 +/- 8.3 versus 19.2 +/- 3.4 ng/mL [conversion factor to SI unit, 1.00]). The ratios between bioactive and immunoactive PRL were comparable. Significant correlation between bioactive and immunoactive PRL was seen for both control (r = 0.616) and unexplained infertility (r = 0.660) groups. CONCLUSION(S): The midcycle elevations of bioactive and immunoactive PRL seen in normal women were absent in women with unexplained infertility. This alteration in PRL dynamics may be a part of subtle differences in the reproductive hormone profile of women with unexplained infertility compared with their fertile counterparts.

Cocaine's lethality increases during late gestation in the rat: a study of "critical periods" of exposure.

OBJECTIVE: Cocaine-associated morbidities in pregnant women (e.g., abruptio placentae, hypertension, seizures) occur mostly during the final stages of gestation. The purpose of our study was to determine whether cocaine's toxicity and blood levels varied as a function of "critical periods" of exposure during gestation. STUDY DESIGN: To evaluate mortality rates, pregnant Long-Evans rats received subcutaneously 30, 40, or 50 mg/kg cocaine hydrochloride twice daily (C30, C40, and C50 groups) either during gestational days 7 to 13 (midgestation) or gestational days 14 to 20 (late gestation) (n 9 to 20 per group). Serum levels of the cocaine metabolite benzoylecgonine were examined in other groups of rats on either gestational day 13 (mid) or day 20 (late) in the C30 treatment condition (n = 5 and 10 per group). RESULTS: There were no maternal mortalities in the midgestation groups at any dose. In contrast, the late-gestation groups showed a dramatic dose-dependent effect, with maternal mortality rates of 0%, 40%, and 72% in the C30, C40, and C50 groups. The late-gestation group had higher benzoylecgonine levels than the midgestation groups did. CONCLUSIONS: Late gestation was associated with higher maternal mortality rates and higher benzoylecgonine levels, indicating that some underlying physiologic change enhanced cocaine's toxicity as pregnancy progressed. This increased sensitivity to cocaine may be mediated by estrogen or progesterone, suggesting that the cocaine-abusing woman is at increased risk for cocaine-induced morbidities whenever levels of these hormones are elevated, such as during the final stages of pregnancy or possibly when taking oral contraceptives.

Cord blood carbohydrate-deficient transferrin levels are markedly higher than maternal.

Regular, heavy alcohol intake results in transferrin that is deficient in carbohydrate moieties. Carbohydrate-deficient transferrin (CDT) has been used as a biologic marker of heavy alcohol exposure in nonpregnant humans. There have been no reports of CDT levels in pregnancy. Our objective was to determine maternal and cord blood levels of CDT. Parturients were recruited at delivery based on graded representative alcohol consumption, from abstainers to heavy drinkers, as determined by screeners skilled at eliciting drug and alcohol histories. Maternal and cord blood serum samples were obtained at delivery. A double antibody radioimmunoassay was used to determine CDT in each sample. There were 83 paired specimens analyzed by paired t tests and stepwise regression analysis. Cord blood CDT units/liter (44.0 +/- 29.5) were significantly (P < 0.0001) higher than maternal (18.4 +/- 7.0). Maternal and cord CDT did not correlate with race, perinatal risk score, gestational age at delivery, birth weight, Apgar scores, or reported alcohol intake. Maternal CDT levels had a significant negative correlation with cigarette smoking. Cord blood CDT levels are significantly higher than maternal. While regular, heavy alcohol consumption by adults results in serum transferrin deficient in carbohydrate moieties, the reason for elevated fetal CDT is unknown.

Euprolactinemic Galactorrhea. Response of bioassayable prolactin to thyrotropin-releasing hormone.

OBJECTIVE: To define whether the pathophysiology of euprolactinemic galactorrhea (EuG) involves hyperresponsiveness to thyrotropin-releasing hormone (TRH). STUDY DESIGN: Basal and TRH-induced prolactin (PRL) patterns were examined in women with EuG (n = 7) and compared to those in controls (n = 10) with normal menstrual cycles. PRL activity was measured by radioimmunoassay (RIA) and Nb2 lymphoma cell bioassay (BA). The response of BA-PRL, RIA-PRL, the BA/RIA-PRL ratio and lactogenic activity to TRH given intravenously were studied. RESULTS: The response of RIA-PRL, BA-PRL, lactogenic activity (representing both PRL and growth hormone in the Nb2 lymphoma cell bioassay) and BA/RIA-PRL ratio were not significantly different in EuG as compared to controls. In both groups the combined BA/ RIA-PRL ratio increased at 15 (P = .006), 30 (P = .011), and 90 minutes (P = .022) after TRH injection as compared to zero time. The level of serum progesterone at the time of TRH stimulation did not affect the response of any parameter studied. CONCLUSION: The response of BA-PRL, RIA-PRL and the BA/RIA-PRL ratio to TRH was not significantly different in EuG as compared to controls. The mechanism of EuG did not involve hyperresponsiveness of BA-PRL, RIA-PRL, the BA/RIA-PRL ratio or lactogenic activity to TRH.

Comparative effects of prenatal cocaine, alcohol, and undernutrition on maternal/fetal toxicity and fetal body composition in the Sprague-Dawley rat with observations on strain-dependent differences.

Pregnant rats received either 20, 30, 40, or 50 mg/kg cocaine HCl (SC) twice daily from gestation days 7 through 19. Pair-fed and untreated control groups and a group receiving 3.0 g/kg alcohol (PO) twice daily served as comparison groups. Females were sacrificed on gestation day 20 and the fetuses examined. Maternal weight gain and food consumption showed dose-dependent decreases. Maternal water consumption, by contrast, was significantly increased in the cocaine-treated animals and may reflect a diuretic effect. The maternal mortality rates in Sprague-Dawley rats were less than in two strains of Long-Evans rats, suggesting important strain-dependent differences in susceptibility to cocaine toxicity. Cocaine caused a significant dose-dependent decrease in fetal weights. Physical anomalies in the cocaine-exposed and alcohol-exposed fetuses included occasional hemorrhaging, edema, anophthalmia, and limb reduction. Despite increased maternal water consumption by cocaine-treated dams, there were no increases in fetal body water content. There were, however, significant decreases in fetal body fat content in the pair-fed, alcohol-treated, and two highest cocaine-treated groups.

Voluntary exercise increases gonadotropin secretion in male Golden hamsters.

To determine the effect of voluntary exercise and food restriction on reproductive hormone secretion, 48 adult male hamsters were placed in cages with (EX) or without (SED) running wheels. One-half of the animals in each exercise group was fed ad libitum, and the other half was food restricted to reduce their body weight to 90 g over 4 wk. After 10 wk, the EX ad libitum-fed group had much larger testes and much higher serum follicle-stimulating hormone and testosterone levels than the other three groups, but these values in the EX food-restricted hamsters were similar to those in the SED food-restricted group. In experiment 2, 20 adult male hamsters were castrated and later implanted with silicone rubber capsules containing testosterone. Two weeks after implantation of the capsules, the serum follicle-stimulating hormone levels were higher in the EX than in the SED group of testosterone-treated hamsters, but not in animals receiving blank capsules. These data suggest that exercise increases gonadotropin secretion by inhibiting the negative feedback of testosterone.

Effects of chronic alcohol administration on lactational performance in the rat.

Lactating rats, with litters adjusted to eight pups on day 2, were implanted with an atrial catheter on day 3 of lactation. Alcohol in doses of 0.0, 1.0, or 2.0 g/kg BW was infused from day 5 to 12. The blood alcohol levels (BALs) achieved following infusion of the initial doses were maintained for 4 hours daily by infusion. To control for the reduced food intake in alcohol administered groups, rats receiving alcohol doses of 0.0 and 1.0 g/kg BW were pairfed to 2.0 g/kg BW alcohol group. For infusion, combinations of 50% dextrose, 30% alcohol in saline and saline solutions were used for 0.0 and 1.0 g/kg BW alcohol groups whereas the 2.0 g/kg BW alcohol group received 30% alcohol in saline thereby equilizing the calorie intake of the three experimental groups. On day 12, pups were separated from the dams at 0800 h, a catheter extension was attached at 0900 h and baseline blood samples for prolactin level were taken at 1000 h. Following infusion of initial alcohol doses, samples were taken for BALs. Additional samples for BALs were removed 2 h after continuing the infusion. At the end of 4-h infusion, blood samples were taken for alcohol and postinfusion prolactin levels. In groups designed to study the suckling-induced prolactin release, pups were weighed and returned to the dams. Subsequent blood samples were taken 30 min after initiation of suckling. In nonsuckled groups, blood samples were obtained at corresponding time periods. BALs were determined by head space gas chromatography and plasma prolactin by a double antibody radioimmunoassay. Suckling latency and milk consumption during the 30 min of suckling were measured. Dams' and litter weights were determined on days 2, 5, and 12 of lactation. Infusion of alcohol for 8 days from day 5 to 12 of lactation did not affect maternal body weight. However, litters nursed by dams receiving 2.0 g/kg BW alcohol weighted less on day 12 compared to all other groups. Suckling latencies did not differ among groups. Milk consumed during the 30 min of suckling was lower for the alcohol administered groups. The inhibitory effect on milk consumption was greater for the 2.0 g/kg BW group than in the 1.0 g/kg BW alcohol group. Alcohol infusion did not affect the basal prolactin, whereas, the higher dose (2.0 g/kg BW) inhibited suckling-induced prolactin release.(ABSTRACT TRUNCATED AT 400 WORDS)

Attenuation of the magnitude of suckling-induced prolactin release with advancing lactation: mechanisms.

To study why suckling-induced plasma prolactin levels decline in magnitude with advancing lactation, we examined prolactin release in lactating rats following suckling and pharmacologic manipulations during early, mid- and late lactation. On day 2 of lactation, litters were adjusted to 8 pups. On day 3, dams were implanted with an atrial catheter and experiments were conducted on lactation days 5, 11 and 17. To examine suckling-induced prolactin release, pups were removed at 0800 h, an extension was attached to the catheter at 1100 h, and pups returned to dams at 1200 h. Blood samples were obtained before, and at 10, 30, 60, 90 and 120 min after suckling started. Prolactin responses to sulpiride and thyrotropin releasing hormone (TRH) administration were studied in lactating rats separated from their litters for 4 hours. Blood samples were obtained before, and at 10, 30, 60 and 90 min after sulpiride (10 or 40 micrograms/kg BW) and 5, 10, 20 and 30 min after TRH (1 or 4 micrograms/kg BW) in rats pretreated with sulpiride. Prolactin release in response to suckling, administration of sulpiride or sulpiride and TRH diminished as lactation advanced. From these results, we conclude that refractoriness in anterior pituitary lactrotropes to prolactin-releasing stimuli is at least partially responsible for the decline in suckling-induced prolactin release with advancing lactation.

Prolactin secretion in lactating rats following chronic alcohol exposure: provocative tests with secretagogues.

This study was done to examine the mechanism of action of alcohol in inhibiting suckling-induced prolactin release in the lactating rat. Alcohol (0.0, 1.0 or 2.0 g/kg body weight) was administered daily for 8 days from day 5 to 12 of lactation via an indwelling atrial catheter, implanted on day 3 of lactation. Following the administration of the initial alcohol dose, infusion was continued at rates required to maintain the blood alcohol levels (BALs) for four hours every day. Prolactin responses to sulpiride and TRH were tested on day 12. Alcohol administration for 8 days and maintaining the blood alcohol levels for four hours daily did not affect the basal or sulpiride and TRH-stimulated plasma prolactin release. Since the prolactin releasing capacity of pituitary lactotropes of the lactating rat is not compromised following chronic alcohol exposure, we conclude that alcohol does not act at the anterior pituitary level to inhibit the suckling induced prolactin release but probably acts by other mechanisms: either via the hypothalamic and/or higher central nervous system or by disrupting the neural impulse transmission, engendered at the nipples in response to suckling.

Beta-endorphin-stimulated prolactin release in lactating rats following alcohol administration.

To delineate the mechanism of alcohol inhibition of the suckling-induced prolactin increase, we examined beta-endorphin-stimulated prolactin release in lactating rats separated from their litters. On day 2 of lactation litters were adjusted to eight pups. On day 7, dams were implanted with an atrial catheter; experiments were conducted on lactation day 10. Litters were separated from their dams at 0800. After five hours, a PE50 extension tube filled with heparinized saline was attached to the catheter. At 1400 a preinfusion blood sample was removed and was followed by infusion of saline (control) or alcohol in saline (1.0 and 2.0 g/kg/body weight). Following the removal of a postinfusion blood sample, beta-endorphin (600 micrograms/kg/body weight) was administered. Additional blood samples were withdrawn 10, 30, 60, and 120 min after beta-endorphin. Alcohol infusion did not alter basal prolactin. beta-Endorphin administration resulted in pronounced prolactin increases in all groups. Alcohol failed to inhibit beta-endorphin-induced plasma prolactin increase. From the present study with beta-endorphin and our previous studies with sulpiride and thyrotropin-releasing hormone (TRH) it is concluded that the anterior pituitary is not the site where alcohol acts to inhibit suckling-induced prolactin release in rats.

Alcohol effects on TRH-induced prolactin response in lactating rats: in vivo and in vitro studies.

The site of action of alcohol in inhibiting suckling-induced prolactin release in lactating rats was examined by in vivo and in vitro studies. In vivo, sulpiride- and thyrotropin-releasing hormone (TRH)-induced prolactin release was studied in lactating rats separated from their litter. On day 7, dams were implanted with an atrial catheter. On day 10, pups were removed from dams at 0800 h and, after 5 h, an extension was attached to the catheter. An hour later, a baseline blood sample was removed and was followed by sulpiride (40 micrograms/kg) administration. Additional blood samples were withdrawn over 1 h. After the 60-min sample, sulpiride-administered rats were infused with 0.0, 1.0, or 2.0 g/kg b.wt. alcohol. Following alcohol, a postinfusion blood sample was removed, TRH (4.0 micrograms/kg) was administered, and subsequent blood samples were obtained 5, 10, 20, and 30 min after TRH. For in vitro studies, cells from lactating rats in midlactation were enzymatically dissociated, plated, and on culture day 5 were exposed to 0 or 10 nM TRH. Each set of cells were additionally exposed to 0, 100, or 300 mg% alcohol and media harvested after 4 h. In a subsequent study, plated cells were exposed to increasing doses of TRH in the presence of 0, 100, or 300 mg% alcohol and media harvested as above. Prolactin in plasma (in vivo studies) and medium (in vitro studies) was measured by RIA.(ABSTRACT TRUNCATED AT 250 WORDS)

Lactation and prolactin release in foster dams suckling prenatally ethanol exposed pups.

The effect of prenatal ethanol exposure on lactation was studied employing prenatally ethanol-exposed pups transferred to foster dams following parturition. During pregnancy, from day 8 to term, dams consumed either standard laboratory chow (ad libitum control), or liquid diets containing 0%, 17.5%, or 35% ethanol derived calories (EDC). To equalize caloric intake, the 0% and 17.5% EDC groups were pair-fed to rats in 35% EDC group. Following delivery, pups born to dams fed with laboratory chow (control) or liquid diets containing 0, 17.5, or 35% EDC were adjusted to eight per litter and transferred to foster dams, which had been fed laboratory chow and water ad libitum throughout pregnancy. Foster dams were implanted with an atrial catheter on day 3 of lactation. On days 6 (early lactation) and 10 (midlactation), following separation of litters from dams for a 6-hr period, a baseline blood sample was removed via a catheter extension. Pups were weighed and returned to the dams. Subsequent blood samples were obtained 10, 30, 60, 120, and 180 min after initiation of suckling. Suckling latency and the amount of milk consumed during the 3-hr suckling were also determined. Litters were weighed on days 2, 6, 10, and 21. The prolactin surge in foster dams in response to suckling by prenatally ethanol-exposed pups was not altered on day 6 of lactation. On day 10, after the initial rise, suckling-induced prolactin was amplified in dams suckled by prenatally ethanol-exposed pups.(ABSTRACT TRUNCATED AT 250 WORDS)

Histology of ovaries of female rabbits immunized with deglycosylated zona pellucida macromolecules of pigs.

Female rabbits (n = 36, 6 per group) were immunized with: (i) solubilized isolated porcine zona pellucida (SIZP), which contains ZP1, 82 kDa; ZP3 alpha, 55 kDa; and ZP3 beta, 55 kDa; (ii) a purified preparation of ZP3 alpha and ZP3 beta (ZP3); (iii) purified endo-beta-galactosidase digested glycoproteins ZP3 alpha-(EBGD) and (iv) ZP3 beta-(EBGD) (each about 30% deglycosylated); (v) chemically deglycosylated core proteins ZP3 alpha-(DG) and (vi) ZP3 beta-DG (each greater than 92% deglycosylated). Rabbits injected with saline (n = 6) or Freund's adjuvant (n = 6) served as controls. Rabbits were bled weekly to monitor titres. Every six weeks two animals from each group (n = 16) were selected for unilateral oophorectomy followed by histological examination. Sections were scored for numbers of primary, secondary and tertiary follicles. Anti-ZP3 titres developed in all treatment groups and correlated with carbohydrate content (peak per cent [125I]-labelled ZP3 binding by radioimmunoassay: SIZP 71.9 +/- 1.2, ZP3 70.0 +/- 2.5, ZP3 alpha-EBGD 60.9 +/- 5.3, ZP3 beta-EBGD 56.4 +/- 5.0, ZP3 alpha-DG 56.4 +/- 4.0, ZP3 beta-DG 53.5 +/- 4.3) (means +/- SEM). Animals immunized with SIZP, ZP3 and ZP3 beta-EBGD showed a statistically significant reduction in the number of primary, secondary and tertiary follicles compared with controls (P less than 0.01, MANOVA), whereas animals immunized with ZP3 alpha-EBGD, ZP3 alpha-DG and ZP3 beta-DG did not (P greater than 0.05, MANOVA). These results demonstrate that immunization with purified ZP3 alpha macromolecules (ZP3 alpha-EBGD, ZP3 alpha-DG) or ZP3 beta-DG does not produce histopathological changes in ovaries. Such deglycosylated ZP macromolecules represent potential target antigens for immunocontraceptive development.