Expression of fibroblast growth factor 13 (Fgf13) mRNA in bovine antral follicles and corpora lutea

Recent studies have suggested a paracrine role for several fibroblast growth factors (FGFs) in the regulation of follicle and luteal development. Fgf13 is a non-secreted FGF that has been previously localized to the developing gonads, but it is not known if it is expressed in the adult ovary. The objective of the present study was to determine the expression pattern of Fgf13 mRNA in the bovine ovary. Fgf13 mRNA expression was examined by semiquantitative RT-PCR using Gapdh as the internal control gene in theca and granulosa cells, corpora lutea (CL) and oocytes collected from abattoir ovaries. Follicles were grouped according to estradiol content (<5, 5-20, >20-100 and >100 ng/ml) and size (5-7, 8-10 and >10 mm diameter). CL samples were morphologically classified into four developmental stages. Fgf13 mRNA expression was assessed in pools containing 50 oocytes aspirated from follicles larger than 4 mm in diameter. ANOVA was used to test for the main effects of follicle size group, and estradiol concentration group in granulosa and theca cells, and to test the effect of CL developmental stage on Fgf13 mRNA abundance. Fgf13 mRNA was detected in the CL and in somatic follicle cells, but not in oocytes. Thecal Fgf13 expression increased with increasing follicle diameter but did not change with intrafollicular estradiol concentrations. No evidence of developmental regulation of Fgf13 mRNA expression was observed in granulosa cells and CL. The present data demonstrate for the first time the expression of an intracellular FGF in the bovine ovary and suggests that Fgf13 mRNA is upregulated in bovine theca cells during antral follicle growth.(AU)

Expression of fibroblast growth factor 13 (Fgf13) mRNA in bovine antral follicles and corpora lutea

Recent studies have suggested a paracrine role for several fibroblast growth factors (FGFs) in the regulation of follicle and luteal development. Fgf13 is a non-secreted FGF that has been previously localized to the developing gonads, but it is not known if it is expressed in the adult ovary. The objective of the present study was to determine the expression pattern of Fgf13 mRNA in the bovine ovary. Fgf13 mRNA expression was examined by semiquantitative RT-PCR using Gapdh as the internal control gene in theca and granulosa cells, corpora lutea (CL) and oocytes collected from abattoir ovaries. Follicles were grouped according to estradiol content (20-100 and >100 ng/ml) and size (5-7, 8-10 and >10 mm diameter). CL samples were morphologically classified into four developmental stages. Fgf13 mRNA expression was assessed in pools containing 50 oocytes aspirated from follicles larger than 4 mm in diameter. ANOVA was used to test for the main effects of follicle size group, and estradiol concentration group in granulosa and theca cells, and to test the effect of CL developmental stage on Fgf13 mRNA abundance. Fgf13 mRNA was detected in the CL and in somatic follicle cells, but not in oocytes. Thecal Fgf13 expression increased with increasing follicle diameter but did not change with intrafollicular estradiol concentrations. No evidence of developmental regulation of Fgf13 mRNA expression was observed in granulosa cells and CL. The present data demonstrate for the first time the expression of an intracellular FGF in the bovine ovary and suggests that Fgf13 mRNA is upregulated in bovine theca cells during antral follicle growth.

Evidence that behavioral depression does not influence airway cell influx in allergic rats.

This study was designated to evaluate the influence of behavioral depression on the airway leukocyte recruitment in allergic animals. To achieve this, total and differential cell counts in bronchoalveolar (BAL) fluid of ovalbumin (OVA)-sensitized and depressed rats was evaluated. Inescapable electric footshock, applied on day 0, 7 and 13 after OVA sensitization, was used as a model to induce depression. In both nondepressed and depressed groups, the number of total and differential cells (eosinophils and mononuclear cells) in BAL fluid was significantly larger in sensitized compared with non-sensitized animals. However, no statistical differences were found between these groups with respect to the number of total and differential leukocytes, irrespective of the day inescapable shock was applied. Thus, behavioral depression does not influence the pattern of cell infiltration into the airways of allergen-induced airway inflammation.

Chronic mild prenatal stress exacerbates the allergen-induced airway inflammation in rats.

The effects of chronic mild prenatal stress on leukocyte infiltration into the airways was investigated in rat offspring. The chronic prenatal stress consisted of transitory and variable changes in the rat's living conditions. Offspring at adult age were actively sensitized (day 0) and intratracheally challenged (day 14) with ovalbumin. Bronchoalveolar lavage was performed in the offspring at 48 h after intratracheal challenge with ovalbumin. A significant increase in total leukocyte infiltration was observed in the non-stressed offspring group and this was associated with a marked recruitment of eosinophils without a significant effect on the influx of neutrophils and mononuclear cells. In the prenatal stressed offspring, the counts of both total leukocyte and eosinophils, as well as mononuclear cells, was increased by 50% compared to the non-stressed offspring. We provide here the first experimental evidence that chronic mild unpredictable prenatal stress produces a marked increase in the allergen-induced airway inflammation in the rat offspring.

Prenatal and postnatal depression among low income Brazilian women.

Postnatal depression is a significant problem affecting 10-15% of mothers in many countries and has been the subject of an increasing number of publications. Prenatal depression has been studied less. The aims of the present investigation were: 1) to obtain information on the prevalence of prenatal and postnatal depression in low income Brazilian women by using an instrument already employed in several countries, i.e., the Edinburgh Postnatal Depression Scale (EPDS); 2) to evaluate the risk factors involved in prenatal and postnatal depression in Brazil. The study groups included 33 pregnant women interviewed at home during the second and third trimesters of pregnancy, and once a month during the first six months after delivery. Questions on life events and the mother's relationship with the baby were posed during each visit. Depressed pregnant women received less support from their partners than non-depressed pregnant women (36.4 vs 72.2%, P < 0.05; Fisher exact test). Black women predominated among pre- and postnatally depressed subjects. Postnatal depression was associated with lower parity (0.4 +/- 0.5 vs 1.1 +/- 1.0, P < 0.05; Student t-test). Thus, the period of pregnancy may be susceptible to socio-environmental factors that induce depression, such as the lack of affective support from the partner. The prevalence rate of 12% observed for depression in the third month postpartum is comparable to that of studies from other countries.

Prenatal and postnatal depression among low income Brazilian women

Postnatal depression is a significant problem affecting 10-15 percent of mothers in many countries and has been the subject of an increasing number of publications. Prenatal depression has been studied less. The aims of the present investigation were: 1) to obtain information on the prevalence of prenatal and postnatal depression in low income Brazilian women by using an instrument already employed in several countries, i.e., the Edinburgh Postnatal Depression Scale (EPDS); 2) to evaluate the risk factors involved in prenatal and postnatal depression in Brazil. The study groups included 33 pregnant women interviewed at home during the second and third trimesters of pregnancy, and once a month during the first six months after delivery. Questions on life events and the mother's relationship with the baby were posed during each visit. Depressed pregnant women received less support from their partners than non-depressed pregnant women (36.4 vs 72.2 percent, P<0.05; Fisher exact test). Black women predominated among pre- and postnatally depressed subjects. Postnatal depression was associated with lower parity (0.4 ñ 0.5 vs 1.1 ñ 1.0, P<0.05; Student t -test). Thus, the period of pregnancy may be susceptible to socio-environmental factors that induce depression, such as the lack of affective support from the partner. The prevalence rate of 12 percent observed for depression in the third month postpartum is comparable to that of studies from other countries

Chronic prenatal stress affects development and behavioral depression in rats.

We have used the approach of Willner et al (1987), which consists of transitory and variable changes in the rat"s living conditions, to investigate the influence of chronic prenatal stress on pup development and their susceptibility to behavioral depression at adult age, as assessed by the learned helplessness model. Pregnant female Wistar rats were divided into either stressed (S; N = 35) or non-stressed (NS; N = 35) groups during the last two weeks of pregnancy. The male and female pups of both groups were either handled to test for physical development up to weaning (H; N = 25 litters) or left undisturbed (NH; N = 10 litters) until adult age, at which time the males from all four experimental groups were divided into two subgroups (N = 10 each) and were submitted to the learned helplessness model of depression. Prenatal stress reduced the number of male pups per litter, decreased the anogenital distance, and produced earlier earflap and eye opening dates, as well as a faster righting. Behavioral depression was induced in all cases, except in the NS-H animals. The prenatally stressed, non-handled pups showed greater escape latency than the NS subgroups. We conclude that the stress schedule used in this study was stressful to dams and sufficient to affect the pups" development and to increase the intensity of induced behavioral depression at adult age.

Effects of naltrexone and cross-tolerance to morphine in a learned helplessness paradigm.

Opiates have been implicated in learned helplessness (LH), a phenomenon known to be related to opiate stress-induced analgesia (SIA). In the present study, we investigated the role of opiates in the induction of LH and SIA under different conditions. Adult female Wistar rats were trained either by receiving 60 inescapable 1-mA footshocks (IS group, N = 114) or by confinement in the shock box (control or NS group, N = 92). The pain threshold of some of the animals was immediately evaluated in a tail-flick test while the rest were used 24 h later in a shuttle box experiment to examine their escape performance. The opiate antagonist naltrexone (0 or 8 mg/kg, ip) and the previous induction of cross-tolerance to morphine by the chronic administration of morphine (0 or 10 mg/kg, sc, for 13 days) were used to identify opiate involvement. Analysis of variance revealed that only animals in the IS group demonstrated antinociception and an escape deficit, both of which were resistant to the procedures applied before the training session. However, the escape deficit could be reversed if the treatments were given before the test session. We conclude that, under our conditions, induction of the LH deficit in escape performance is not opiate-mediated although its expression is opiate-modulated.

Effects of naltrexone and cross-tolerance to morphine in a learned helplessness paradigm

Opiates have been implicated in learned helplessness (LH), a phenomenon known to be related to opiate stress-induced analgesia (SIA). In the present study, we investigated the role of opiates in the induction of LH and SIA under different conditions. Adult female Wistar rats were trained either by receiving 60 inescapable 1-mA footshocks (IS group, N = 114) or by confinement in the shock box (control or NS group, N = 92). The pain threshold of some of the animals was immediately evaluated in a tail-flick test while the rest were used 24 h later in a shutttle box experiment to examine their escape performance. The opiate antagonist naltrexone (0 or 8 mg/kg, ip) and the previous induction of cross-tolerance to morphine by the chronic administration of morphine (0 or 10 mg/kg, sc, for 13 days) were used to identify opiate involvement. Analysis of variance revealed that only animals in the IS group demonstrated antinociception and an escape deficit, both of which were resistant to the procedures applied before the training session. However, the escape deficit could be reversed if the treatments were given before the test session. We conclude that, under our conditions, induction of the LH deficit in escape performance is not opiate-mediated although its expression is opiate-modulated.

Regulation of stress-induced reduced myelopoiesis in rats.

In this work we demonstrate that the stress-induced reduction in bone marrow granulocyte-macrophage colonies, reported previously from our laboratory, is prevented by both the inhibition of the hypothalamic-pituitary-adrenal axis (HPAA) and the blockage of opioid receptors. The inhibition of the HPAA was obtained through the administration of dexamethasone (1 mg/kg). The blockage of opioid receptors was done in two ways, by the administration of naltrexone (8 mg/kg) and induction of tolerance to morphine. On the other hand, no protection was observed in metyrapone treated rats. We suggest that the two physiological systems, opioid and HPAA, mediate the stress-induced myelosuppression and that these systems may function independently in this particular situation.

Hematopoietic changes in rats after inescapable and escapable shocks.

Bone marrow cell responsiveness to hematopoietic growth factors was investigated in rats only confined or experiencing inescapable, escapable shocks or no electric shock. The results demonstrated a significant reduction in the number of granulocyte-macrophage precursors in the bone marrow of confined rats and of rats exposed to inescapable shocks. The reversibility of this mielossupressive response was seen in both groups and occurred first in the confined animals. No changes were observed in the group submitted to escapable shocks when compared to controls.

Chronic but not acute Li+ treatment prevents behavioral depression in rats.

The effect of lithium administration on the learned helplessness model of depression was investigated. Female Wistar rats (190-210 g) received either tap water alone (N = 156) or 20 mM LiCL provided chronically (30 days; N = 127) or acutely (5 days; N = 22) in the drinking water. Three days before the end of treatment, each group was divided into two subgroups which received either inescapable shock (IS) or no shock (NS) treatment in shuttle boxes. All groups were subsequently submitted to an escape test on the following day and then sacrificed one day after the escape test, when blood samples were taken to measure serum Li+, Na+ and K+ concentrations by flame photometry. There were no significant differences in serum Na+ amongst the 4 groups. Chronically treated NS and IS rats both presented an increase in serum K+ compared to the control rats. The IS and not the NS chronically treated rats presented increased serum Li+ levels which cannot be accounted for in terms of differences in Li+ intake. The IS group treated chronically with lithium had a better escape performance than the IS group receiving either tap water or acute Li+ administration. We conclude that chronic but not acute Li+ treatment at a serum level within the prophylactic range (0.5 mEq/l) is able to prevent learned helplessness in the rat. These results agree with the data obtained in clinical practice indicating that Li+ is only effective after chronic administration and that Li(+)-induced hyperkalemia is a side effect.

Chronic but not acute Li+ treatment prevents behavioral depression in rats

The effect of lithium administration on the learned hellessness model of depression was investigated. Female Wistar rats (190-210g) received either tap water alone (N=156) or 20 mM LiCL, provided chronically (30 days; N = 127) or acutely (5 days; N = 22), in the drinking water. Three days before the end od treatment, each group was divided into two subgroups which received either inescapable shock (IS) or no shock (NS) treatment in shuttle boxes. All groups were subsequenty submitted to an escape test on the following day and then sacrificed one day after the escape test, when blood samples were taken to measure serum Li+, Na+ and K+ concentrations by flame photometry. There were no significant differences in serum Na+ amongst the 4 groups. chronically treated NS and IS rats both presented an increase in serum K+ compared to the control rats. The IS and not the NS chronically treated rats presented increased serum Li+ levels which cannot be accounted for in terms of differences in Li+ intake. The IS group treated chronically with lithium had a better escape performance than the IS group receiving either tap water or acute Li+ administration. We conclude that chronic but not acute Li+ treatment at a serum level within the prophylactic range (0,5 mEq) is able to prevent learned helplessness in the rat. These results agree with the data obtained in clinical practice indicating that li+ is only effective after chronic administration and that Li+ - induced hyperkalemia is a side effect

Lithium treatment prolongs shock-induced hypoalgesia.

We have investigated the effect of chronic lithium (Li+) treatment on stress-induced hypoalgesia, a phenomenon known to be dependent on the activation and sensitization of the central opioid system. Adult female Wistar rats received either 20 mM LiCl in the drinking water (serum level of 0.5 mEq/l, N = 110) or tap water (controls, N = 113) for 28 days. The rats were divided into three subgroups and were trained either by receiving 60 inescapable 1-mA footshocks (IS) while yoked to an escapable (ES) group, or by confinement (NS) to the shock box. As a control for the activation of the opioid system, we included rats injected with 0.9% saline (N = 24) or morphine (4 mg/kg, sc, N = 20) before confinement. Twenty-four hours later, the rats (N = 187) were either submitted to five inescapable (1 s, 0.6 mA) footshocks (shock reexposure) or received no shocks over the same period (N = 80). The pain threshold was estimated using a tail-flick apparatus after the training session and immediately after the shock reexposure. ANOVA followed by Duncan's test indicated that hypoalgesia was produced soon after the training session in the morphine and shocked groups and persisted in the Li(+)-IS group for up to three days. Hypoalgesia was reinstated in the control IS and morphine groups by reexposure to the shocks, but was not modified in the Li(+)-IS groups. We conclude that Li+ treatment prolongs the hypoalgesia induced by inescapable shocks.

Lithium treatment prolongs shock-induced hypoalgesia

We have investigated the effect of chronic lithium (Li+) treatment on stress-induced hypoalgesia, a phenomenon known to be dependent on the activation and sensitization of the central opioid system. Adult female Wistar rats received either 20 mM LiCl in the drinking water (serum level of 0.5 mEq/l,N = 110) or tap water (controls N = 113) for 28 days. The rats were divided into three subgroups and were trained either by receiving 60 inescapable 1-mA footshocks (IS) while yoked to a escapable (ES) group, or by confinement (NS) to the shock box. As a control for the activation of the opioid system, we included rats injected with 0.9 percent saline (N = 24) or morphine (4 mg/kg, sc, N =20) before confinement. Twenty-four hours later, the rats (N = 187) were either submitted to five inescapable (1 s,0.6 mA) footshocks (shock reexposure) or received no shocks over the same period (N = 80). The pain threshold was estimated using a tail-flick apparatus after the training session and immediately after the shock reesposure. ANOVA followed by duncan's test indicated that hypoalgesia was produced soon after the training session in the morphine and shocked groups and persisted in the Li+-IS group for up to three days. Hypoalgesia was reinstated in the control IS and morphine groups by reexposure to the shochs, but was not modified in the Li+-IS groups. We conclude that Li+ treatment prolongs the hypoalgesia induced by inescapable shocks

Developmental toxicity of lithium treatment at prophylactic levels.

Lithium (Li+) salts are frequently used in psychiatry and may be administered to women in their reproductive years. We have investigated the influence of chronic Li+ administration on rat offspring. Pregnant Wistar rats drank either tap water ad libitum or 10 mM LiCl, or were water restricted (paired to rats receiving LiCl) until pup weaning. Following birth, pups were fostered to form five experimental groups (N = numbers of litters): a) Control-S, stressed by water restriction (N = 21), b) Li+ during the prenatal and lactating periods (N = 18), c) Li+ during the prenatal period only (N = 22), d) Li+ during the lactating period only (N = 15), and e) Control-NS no treatment (N = 13). Prenatal water restriction or Li+ treatment impaired the performance of the righting reflex, altered the number of males born and delayed the final date of eye opening. Postnatal water restriction or Li+ treatment of the dams reduced body growth and the date of eye opening of pups. No difference was found in the time to pup earflap opening, or in the motor coordination test. The specific effect of lithium on pups included impairment of the righting reflex, an increase in the number of males born, a reduction in body weight at weaning and a delay in the eye opening date. The serum Li+ levels of the dams were maintained at approximately 0.5 mEq/l. There was an increase in serum potassium, but not sodium, concentrations. We conclude that chronic treatment of dams with Li+ in amounts similar to those used in the prophylaxis of bipolar disorders aggravated the delay in physical and behavioral development of pups produced by stress associated with limited water intake and handling.

Developmental toxicity of lithium treatment at prophylactic levels

Lithium (Li+) salts are frequently used in psychiatry and may be administered to women in theirreproductive years. We have investigated the influence of chronic Li+ administration on rat offspring. Pregnant Wistar rats drank either tap water ad libitum or 10 mM LiCl, or were water restricted (paired to rats receiving LiCl) until pup weaning. Following birth, pups were fostered to form five experimetnal groups (N = numbers of litters): a) Control-S, stressed by water restriction (N = 21), b) Li+ during the prenatal and lactating periods (N=18),c) Li+ during the prenatal period only (N=22), d) Li+ during the lactating period only (N = 15), and e) Control-NS no treatment (N = 13). Prenatal water restriction of Li+ treatment impaired the performance of the righting reflex, altered the number of males born and delayed the final date of eye opening. Postnatal water restriction or Li+ treatment of the dams reduced body growth and the date of eye opening of pups. No difference was found in the time to pup earflap opening, or in the motor coordination test. The specific effect of lithium on pups included impairment of the righting reflex, an increase in the number of males born, a reduction in body weight at weaning and a delay in the eye opening date. The serum Li+ levels of the dams were maintained at approximately 0.5 mEq/l. Ther was an increase in serum potassium, but not sodium, concentrations. We conclude that chronic treatment of dams with Li+ in amounts similar to those used in the prophylaxis of bipolar disorders aggravated the delay in physical and behavioral development of pups produced by stress associated with limited water intake and handling

Reversal of learned helplessness by chronic lithium treatment at a prophylactic level.

1. The effect of chronic lithium (Li) administration in a learned helplessness (LH) model was investigated. Female Wistar rats (190-210 g) received either tap water ad libitum (N = 56) or 20 mM LiCl (N = 63) in the drinking water or were water restricted (35% based on lower liquid intake of rats receiving lithium, N = 40) for 30 days. On the 28th day, each of these groups was divided into three subgroups which received escapable (ES), inescapable (IS) or no shock (NS) treatment in shuttle boxes. All groups were submitted to the escape test on the 29th day and sacrificed on the 30th day, when blood samples were taken for measurement of serum lithium, sodium and potassium concentrations. 2. The NS group had lower serum Li levels (0.36 +/- 0.06, N = 15) than the ES (0.46 +/- 0.07, N = 15) or IS group (0.44 +/- 0.09, N = 25). The Li-pretreated group subjected to IS had a more effective escape performance than the IS group under water restriction and showed the same behaviour as animals not submitted to shocks. 3. We conclude that chronic treatment with Li at a serum level of 0.44 +/- 0.09 mEq/l prevents learned helplessness in rats. These results corroborate the validity of the use of this model for the assessment of the capacity of Li to protect against some depressive episodes.

Reversal of learned helplessness by chronic lithium treatment at a prophylactic level

1. The effect of chronic lithium (Li) administration in a learned helplessness (LH) model was investigated. Female Wistar rats (190-210 g) received either tap water ad libitum (N = 56) or 20 mM LiCl (N = 63) in the drinking water or were water restricted (35 per cent based on lower liquid intake of rats receiving lithium, N = 40) for 30 days. On the 28th day, each of these groups was divided into three subgroups which received escapable (ES), inescapable (IS) or no shock (NS) treatment in shuttle boxes. All groups were submitted to the escape test on the 29th day and sacrificed on the 30th day, when blood samples were taken for measurement of serum lithium, sodium and potassium concentrations. 2. The NS group had lower serum Li levels (0.36 +/- 0.06, N = 15) than the ES (0.46 +/- 0.07, N = 15) or IS group (0.44 +/- 0.09, N = 25). The Li-pretreated group subjected to IS had a more effective escape performance than the IS group under water restriction and showed the same behaviour as animals not submitted to shocks. 3. We conclude that chronic treatment with Li at a serum level of 0.44 +/- 0.09 mEq/l prevents learned helplessness in rats. These results corroborate the validity of the use of this model for the assessment of the capacity of Li to protect against some depressive episodes

Dissociation of the toxic and behavioral effects of lithium on rats.

In a previous study we have shown that weight loss or animal death as a sign of toxicity due to chronic administration of lithium in rats is more intense among male than female adult animals (5 months old), and is not observed in growing male and female animals (2 months old) (Teixeira and Karniol, Acta Pharmacologica et Toxicologica, 51: 1-5, 1982). In this study we report the results obtained for the same animals in the open field test. The ip administration of 3.0 mEq/day of LiCl to female rats for 28 days produced a decrease in rearing (60- and 150-day old animals) and ambulation (150-day old animals) in relation to control animals. Male rats of both ages submitted to the same treatment showed no changes in rearing or ambulation. The low level of activity observed in the male control groups during the 2nd and 4th experimental week may probably explain the lack of lithium effect on the number of rearing (both age groups) and ambulation (older animals) activities. We conclude that, under the present experimental conditions, the behavioral effects of lithium on female rats are dissociated from the toxic action of this substance.